Commit Graph

12148 Commits

Author SHA1 Message Date
Subash Abhinov Kasiviswanathan 227355ad4e tcp: Update window clamping condition
[ Upstream commit a2cbb1603943281a604f5adc48079a148db5cb0d ]

This patch is based on the discussions between Neal Cardwell and
Eric Dumazet in the link
https://lore.kernel.org/netdev/20240726204105.1466841-1-quic_subashab@quicinc.com/

It was correctly pointed out that tp->window_clamp would not be
updated in cases where net.ipv4.tcp_moderate_rcvbuf=0 or if
(copied <= tp->rcvq_space.space). While it is expected for most
setups to leave the sysctl enabled, the latter condition may
not end up hitting depending on the TCP receive queue size and
the pattern of arriving data.

The updated check should be hit only on initial MSS update from
TCP_MIN_MSS to measured MSS value and subsequently if there was
an update to a larger value.

Fixes: 05f76b2d634e ("tcp: Adjust clamping window for applications specifying SO_RCVBUF")
Signed-off-by: Sean Tranchetti <quic_stranche@quicinc.com>
Signed-off-by: Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29 17:33:19 +02:00
Willem de Bruijn 3db4395332 fou: remove warn in gue_gro_receive on unsupported protocol
[ Upstream commit dd89a81d850fa9a65f67b4527c0e420d15bf836c ]

Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
not known or does not have a GRO handler.

Such a packet is easily constructed. Syzbot generates them and sets
off this warning.

Remove the warning as it is expected and not actionable.

The warning was previously reduced from WARN_ON to WARN_ON_ONCE in
commit 270136613b ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad
proto callbacks").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240614122552.1649044-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19 06:04:30 +02:00
Eric Dumazet 77100f2e84 tcp_metrics: optimize tcp_metrics_flush_all()
[ Upstream commit 6532e257aa73645e28dee5b2232cc3c88be62083 ]

This is inspired by several syzbot reports where
tcp_metrics_flush_all() was seen in the traces.

We can avoid acquiring tcp_metrics_lock for empty buckets,
and we should add one cond_resched() to break potential long loops.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19 06:04:25 +02:00
Willem de Bruijn 6772c4868a net: drop bad gso csum_start and offset in virtio_net_hdr
commit 89add40066f9ed9abe5f7f886fe5789ff7e0c50e upstream.

Tighten csum_start and csum_offset checks in virtio_net_hdr_to_skb
for GSO packets.

The function already checks that a checksum requested with
VIRTIO_NET_HDR_F_NEEDS_CSUM is in skb linear. But for GSO packets
this might not hold for segs after segmentation.

Syzkaller demonstrated to reach this warning in skb_checksum_help

	offset = skb_checksum_start_offset(skb);
	ret = -EINVAL;
	if (WARN_ON_ONCE(offset >= skb_headlen(skb)))

By injecting a TSO packet:

WARNING: CPU: 1 PID: 3539 at net/core/dev.c:3284 skb_checksum_help+0x3d0/0x5b0
 ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774
 ip_finish_output_gso net/ipv4/ip_output.c:279 [inline]
 __ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:301
 iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82
 ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813
 __gre_xmit net/ipv4/ip_gre.c:469 [inline]
 ipgre_xmit+0x759/0xa60 net/ipv4/ip_gre.c:661
 __netdev_start_xmit include/linux/netdevice.h:4850 [inline]
 netdev_start_xmit include/linux/netdevice.h:4864 [inline]
 xmit_one net/core/dev.c:3595 [inline]
 dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611
 __dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261
 packet_snd net/packet/af_packet.c:3073 [inline]

The geometry of the bad input packet at tcp_gso_segment:

[   52.003050][ T8403] skb len=12202 headroom=244 headlen=12093 tailroom=0
[   52.003050][ T8403] mac=(168,24) mac_len=24 net=(192,52) trans=244
[   52.003050][ T8403] shinfo(txflags=0 nr_frags=1 gso(size=1552 type=3 segs=0))
[   52.003050][ T8403] csum(0x60000c7 start=199 offset=1536
ip_summed=3 complete_sw=0 valid=0 level=0)

Mitigate with stricter input validation.

csum_offset: for GSO packets, deduce the correct value from gso_type.
This is already done for USO. Extend it to TSO. Let UFO be:
udp[46]_ufo_fragment ignores these fields and always computes the
checksum in software.

csum_start: finding the real offset requires parsing to the transport
header. Do not add a parser, use existing segmentation parsing. Thanks
to SKB_GSO_DODGY, that also catches bad packets that are hw offloaded.
Again test both TSO and USO. Do not test UFO for the above reason, and
do not test UDP tunnel offload.

GSO packet are almost always CHECKSUM_PARTIAL. USO packets may be
CHECKSUM_NONE since commit 10154dbded6d6 ("udp: Allow GSO transmit
from devices with no checksum offload"), but then still these fields
are initialized correctly in udp4_hwcsum/udp6_hwcsum_outgoing. So no
need to test for ip_summed == CHECKSUM_PARTIAL first.

This revises an existing fix mentioned in the Fixes tag, which broke
small packets with GSO offload, as detected by kselftests.

Link: https://syzkaller.appspot.com/bug?extid=e1db31216c789f552871
Link: https://lore.kernel.org/netdev/20240723223109.2196886-1-kuba@kernel.org
Fixes: e269d79c7d35 ("net: missing check virtio")
Cc: stable@vger.kernel.org
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240729201108.1615114-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-14 13:58:48 +02:00
Kuniyuki Iwashima 70014b73d7 netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init().
[ Upstream commit 5830aa863981d43560748aa93589c0695191d95d ]

We had a report that iptables-restore sometimes triggered null-ptr-deref
at boot time. [0]

The problem is that iptable_nat_table_init() is exposed to user space
before the kernel fully initialises netns.

In the small race window, a user could call iptable_nat_table_init()
that accesses net_generic(net, iptable_nat_net_id), which is available
only after registering iptable_nat_net_ops.

Let's call register_pernet_subsys() before xt_register_template().

[0]:
bpfilter: Loaded bpfilter_umh pid 11702
Started bpfilter
BUG: kernel NULL pointer dereference, address: 0000000000000013
 PF: supervisor write access in kernel mode
 PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
PREEMPT SMP NOPTI
CPU: 2 PID: 11879 Comm: iptables-restor Not tainted 6.1.92-99.174.amzn2023.x86_64 #1
Hardware name: Amazon EC2 c6i.4xlarge/, BIOS 1.0 10/16/2017
RIP: 0010:iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat
Code: 10 4c 89 f6 48 89 ef e8 0b 19 bb ff 41 89 c4 85 c0 75 38 41 83 c7 01 49 83 c6 28 41 83 ff 04 75 dc 48 8b 44 24 08 48 8b 0c 24 <48> 89 08 4c 89 ef e8 a2 3b a2 cf 48 83 c4 10 44 89 e0 5b 5d 41 5c
RSP: 0018:ffffbef902843cd0 EFLAGS: 00010246
RAX: 0000000000000013 RBX: ffff9f4b052caa20 RCX: ffff9f4b20988d80
RDX: 0000000000000000 RSI: 0000000000000064 RDI: ffffffffc04201c0
RBP: ffff9f4b29394000 R08: ffff9f4b07f77258 R09: ffff9f4b07f77240
R10: 0000000000000000 R11: ffff9f4b09635388 R12: 0000000000000000
R13: ffff9f4b1a3c6c00 R14: ffff9f4b20988e20 R15: 0000000000000004
FS:  00007f6284340000(0000) GS:ffff9f51fe280000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000013 CR3: 00000001d10a6005 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259)
 ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259)
 ? xt_find_table_lock (net/netfilter/x_tables.c:1259)
 ? __die_body.cold (arch/x86/kernel/dumpstack.c:478 arch/x86/kernel/dumpstack.c:420)
 ? page_fault_oops (arch/x86/mm/fault.c:727)
 ? exc_page_fault (./arch/x86/include/asm/irqflags.h:40 ./arch/x86/include/asm/irqflags.h:75 arch/x86/mm/fault.c:1470 arch/x86/mm/fault.c:1518)
 ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:570)
 ? iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat
 xt_find_table_lock (net/netfilter/x_tables.c:1259)
 xt_request_find_table_lock (net/netfilter/x_tables.c:1287)
 get_info (net/ipv4/netfilter/ip_tables.c:965)
 ? security_capable (security/security.c:809 (discriminator 13))
 ? ns_capable (kernel/capability.c:376 kernel/capability.c:397)
 ? do_ipt_get_ctl (net/ipv4/netfilter/ip_tables.c:1656)
 ? bpfilter_send_req (net/bpfilter/bpfilter_kern.c:52) bpfilter
 nf_getsockopt (net/netfilter/nf_sockopt.c:116)
 ip_getsockopt (net/ipv4/ip_sockglue.c:1827)
 __sys_getsockopt (net/socket.c:2327)
 __x64_sys_getsockopt (net/socket.c:2342 net/socket.c:2339 net/socket.c:2339)
 do_syscall_64 (arch/x86/entry/common.c:51 arch/x86/entry/common.c:81)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
RIP: 0033:0x7f62844685ee
Code: 48 8b 0d 45 28 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 09
RSP: 002b:00007ffd1f83d638 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007ffd1f83d680 RCX: 00007f62844685ee
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000004 R08: 00007ffd1f83d670 R09: 0000558798ffa2a0
R10: 00007ffd1f83d680 R11: 0000000000000246 R12: 00007ffd1f83e3b2
R13: 00007f628455baa0 R14: 00007ffd1f83d7b0 R15: 00007f628457a008
 </TASK>
Modules linked in: iptable_nat(+) bpfilter rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache veth xt_state xt_connmark xt_nat xt_statistic xt_MASQUERADE xt_mark xt_addrtype ipt_REJECT nf_reject_ipv4 nft_chain_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_comment nft_compat nf_tables nfnetlink overlay nls_ascii nls_cp437 vfat fat ghash_clmulni_intel aesni_intel ena crypto_simd ptp cryptd i8042 pps_core serio button sunrpc sch_fq_codel configfs loop dm_mod fuse dax dmi_sysfs crc32_pclmul crc32c_intel efivarfs
CR2: 0000000000000013

Fixes: fdacd57c79 ("netfilter: x_tables: never register tables by default")
Reported-by: Takahiro Kawahara <takawaha@amazon.co.jp>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-11 12:47:22 +02:00
Subash Abhinov Kasiviswanathan 1cfdc250b3 tcp: Adjust clamping window for applications specifying SO_RCVBUF
[ Upstream commit 05f76b2d634e65ab34472802d9b142ea9e03f74e ]

tp->scaling_ratio is not updated based on skb->len/skb->truesize once
SO_RCVBUF is set leading to the maximum window scaling to be 25% of
rcvbuf after
commit dfa2f04833 ("tcp: get rid of sysctl_tcp_adv_win_scale")
and 50% of rcvbuf after
commit 697a6c8cec03 ("tcp: increase the default TCP scaling ratio").
50% tries to emulate the behavior of older kernels using
sysctl_tcp_adv_win_scale with default value.

Systems which were using a different values of sysctl_tcp_adv_win_scale
in older kernels ended up seeing reduced download speeds in certain
cases as covered in https://lists.openwall.net/netdev/2024/05/15/13
While the sysctl scheme is no longer acceptable, the value of 50% is
a bit conservative when the skb->len/skb->truesize ratio is later
determined to be ~0.66.

Applications not specifying SO_RCVBUF update the window scaling and
the receiver buffer every time data is copied to userspace. This
computation is now used for applications setting SO_RCVBUF to update
the maximum window scaling while ensuring that the receive buffer
is within the application specified limit.

Fixes: dfa2f04833 ("tcp: get rid of sysctl_tcp_adv_win_scale")
Signed-off-by: Sean Tranchetti <quic_stranche@quicinc.com>
Signed-off-by: Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-11 12:47:20 +02:00
Eric Dumazet f9fef23a81 tcp: annotate data-races around tp->window_clamp
[ Upstream commit f410cbea9f3d2675b4c8e52af1d1985b11b387d1 ]

tp->window_clamp can be read locklessly, add READ_ONCE()
and WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20240404114231.2195171-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 05f76b2d634e ("tcp: Adjust clamping window for applications specifying SO_RCVBUF")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-11 12:47:19 +02:00
Petr Machata 7704460acd net: nexthop: Initialize all fields in dumped nexthops
[ Upstream commit 6d745cd0e9720282cd291d36b9db528aea18add2 ]

struct nexthop_grp contains two reserved fields that are not initialized by
nla_put_nh_group(), and carry garbage. This can be observed e.g. with
strace (edited for clarity):

    # ip nexthop add id 1 dev lo
    # ip nexthop add id 101 group 1
    # strace -e recvmsg ip nexthop get id 101
    ...
    recvmsg(... [{nla_len=12, nla_type=NHA_GROUP},
                 [{id=1, weight=0, resvd1=0x69, resvd2=0x67}]] ...) = 52

The fields are reserved and therefore not currently used. But as they are, they
leak kernel memory, and the fact they are not just zero complicates repurposing
of the fields for new ends. Initialize the full structure.

Fixes: 430a049190 ("nexthop: Add support for nexthop groups")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:54:38 +02:00
Ido Schimmel 42f493bd6c ipv4: Fix incorrect source address in Record Route option
[ Upstream commit cc73bbab4b1fb8a4f53a24645871dafa5f81266a ]

The Record Route IP option records the addresses of the routers that
routed the packet. In the case of forwarded packets, the kernel performs
a route lookup via fib_lookup() and fills in the preferred source
address of the matched route.

The lookup is performed with the DS field of the forwarded packet, but
using the RT_TOS() macro which only masks one of the two ECN bits. If
the packet is ECT(0) or CE, the matched route might be different than
the route via which the packet was forwarded as the input path masks
both of the ECN bits, resulting in the wrong address being filled in the
Record Route option.

Fix by masking both of the ECN bits.

Fixes: 8e36360ae8 ("ipv4: Remove route key identity dependencies in ip_rt_get_source().")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20240718123407.434778-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:54:37 +02:00
Nicolas Dichtel 0aa47c27f8 ipv4: fix source address selection with route leak
commit 6807352353561187a718e87204458999dbcbba1b upstream.

By default, an address assigned to the output interface is selected when
the source address is not specified. This is problematic when a route,
configured in a vrf, uses an interface from another vrf (aka route leak).
The original vrf does not own the selected source address.

Let's add a check against the output interface and call the appropriate
function to select the source address.

CC: stable@vger.kernel.org
Fixes: 8cbb512c92 ("net: Add source address lookup op for VRF")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240710081521.3809742-2-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03 08:54:13 +02:00
Ido Schimmel 935dec4e42 ipv4: Fix incorrect TOS in fibmatch route get reply
[ Upstream commit f036e68212c11e5a7edbb59b5e25299341829485 ]

The TOS value that is returned to user space in the route get reply is
the one with which the lookup was performed ('fl4->flowi4_tos'). This is
fine when the matched route is configured with a TOS as it would not
match if its TOS value did not match the one with which the lookup was
performed.

However, matching on TOS is only performed when the route's TOS is not
zero. It is therefore possible to have the kernel incorrectly return a
non-zero TOS:

 # ip link add name dummy1 up type dummy
 # ip address add 192.0.2.1/24 dev dummy1
 # ip route get fibmatch 192.0.2.2 tos 0xfc
 192.0.2.0/24 tos 0x1c dev dummy1 proto kernel scope link src 192.0.2.1

Fix by instead returning the DSCP field from the FIB result structure
which was populated during the route lookup.

Output after the patch:

 # ip link add name dummy1 up type dummy
 # ip address add 192.0.2.1/24 dev dummy1
 # ip route get fibmatch 192.0.2.2 tos 0xfc
 192.0.2.0/24 dev dummy1 proto kernel scope link src 192.0.2.1

Extend the existing selftests to not only verify that the correct route
is returned, but that it is also returned with correct "tos" value (or
without it).

Fixes: b61798130f ("net: ipv4: RTM_GETROUTE: return matched fib result when requested")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:54:05 +02:00
Ido Schimmel 015d29dbe4 ipv4: Fix incorrect TOS in route get reply
[ Upstream commit 338bb57e4c2a1c2c6fc92f9c0bd35be7587adca7 ]

The TOS value that is returned to user space in the route get reply is
the one with which the lookup was performed ('fl4->flowi4_tos'). This is
fine when the matched route is configured with a TOS as it would not
match if its TOS value did not match the one with which the lookup was
performed.

However, matching on TOS is only performed when the route's TOS is not
zero. It is therefore possible to have the kernel incorrectly return a
non-zero TOS:

 # ip link add name dummy1 up type dummy
 # ip address add 192.0.2.1/24 dev dummy1
 # ip route get 192.0.2.2 tos 0xfc
 192.0.2.2 tos 0x1c dev dummy1 src 192.0.2.1 uid 0
     cache

Fix by adding a DSCP field to the FIB result structure (inside an
existing 4 bytes hole), populating it in the route lookup and using it
when filling the route get reply.

Output after the patch:

 # ip link add name dummy1 up type dummy
 # ip address add 192.0.2.1/24 dev dummy1
 # ip route get 192.0.2.2 tos 0xfc
 192.0.2.2 dev dummy1 src 192.0.2.1 uid 0
     cache

Fixes: 1a00fee4ff ("ipv4: Remove rt_key_{src,dst,tos} from struct rtable.")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:54:05 +02:00
Eric Dumazet 44aa1e461c tcp: fix races in tcp_v[46]_err()
[ Upstream commit fde6f897f2a184546bf5516ac736523ef24dc6a7 ]

These functions have races when they:

1) Write sk->sk_err
2) call sk_error_report(sk)
3) call tcp_done(sk)

As described in prior patches in this series:

An smp_wmb() is missing.
We should call tcp_done() before sk_error_report(sk)
to have consistent tcp_poll() results on SMP hosts.

Use tcp_done_with_error() where we centralized the
correct sequence.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Link: https://lore.kernel.org/r/20240528125253.1966136-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:53:37 +02:00
Eric Dumazet bc4f9c2ccd tcp: fix race in tcp_write_err()
[ Upstream commit 853c3bd7b7917670224c9fe5245bd045cac411dd ]

I noticed flakes in a packetdrill test, expecting an epoll_wait()
to return EPOLLERR | EPOLLHUP on a failed connect() attempt,
after multiple SYN retransmits. It sometimes return EPOLLERR only.

The issue is that tcp_write_err():
 1) writes an error in sk->sk_err,
 2) calls sk_error_report(),
 3) then calls tcp_done().

tcp_done() is writing SHUTDOWN_MASK into sk->sk_shutdown,
among other things.

Problem is that the awaken user thread (from 2) sk_error_report())
might call tcp_poll() before tcp_done() has written sk->sk_shutdown.

tcp_poll() only sees a non zero sk->sk_err and returns EPOLLERR.

This patch fixes the issue by making sure to call sk_error_report()
after tcp_done().

tcp_write_err() also lacks an smp_wmb().

We can reuse tcp_done_with_error() to factor out the details,
as Neal suggested.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Link: https://lore.kernel.org/r/20240528125253.1966136-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:53:37 +02:00
Eric Dumazet ecc6836d63 tcp: add tcp_done_with_error() helper
[ Upstream commit 5e514f1cba090e1c8fff03e92a175eccfe46305f ]

tcp_reset() ends with a sequence that is carefuly ordered.

We need to fix [e]poll bugs in the following patches,
it makes sense to use a common helper.

Suggested-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Link: https://lore.kernel.org/r/20240528125253.1966136-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 853c3bd7b791 ("tcp: fix race in tcp_write_err()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:53:37 +02:00
Hagar Hemdan 7797efc98e net: esp: cleanup esp_output_tail_tcp() in case of unsupported ESPINTCP
[ Upstream commit 96f887a612e4cda89efc3f54bc10c1997e3ab0e9 ]

xmit() functions should consume skb or return error codes in error
paths.
When the configuration "CONFIG_INET_ESPINTCP" is not set, the
implementation of the function "esp_output_tail_tcp" violates this rule.
The function frees the skb and returns the error code.
This change removes the kfree_skb from both functions, for both
esp4 and esp6.
WARN_ON is added because esp_output_tail_tcp() should never be called if
CONFIG_INET_ESPINTCP is not set.

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

Fixes: e27cca96cd ("xfrm: add espintcp (RFC 8229)")
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:53:36 +02:00
Eric Dumazet dfcdd7f89e tcp: avoid too many retransmit packets
commit 97a9063518f198ec0adb2ecb89789de342bb8283 upstream.

If a TCP socket is using TCP_USER_TIMEOUT, and the other peer
retracted its window to zero, tcp_retransmit_timer() can
retransmit a packet every two jiffies (2 ms for HZ=1000),
for about 4 minutes after TCP_USER_TIMEOUT has 'expired'.

The fix is to make sure tcp_rtx_probe0_timed_out() takes
icsk->icsk_user_timeout into account.

Before blamed commit, the socket would not timeout after
icsk->icsk_user_timeout, but would use standard exponential
backoff for the retransmits.

Also worth noting that before commit e89688e3e9 ("net: tcp:
fix unexcepted socket die when snd_wnd is 0"), the issue
would last 2 minutes instead of 4.

Fixes: b701a99e43 ("tcp: Add tcp_clamp_rto_to_user_timeout() helper to improve accuracy")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Jon Maxwell <jmaxwell37@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240710001402.2758273-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18 13:21:17 +02:00
Eric Dumazet b75f281bdd tcp: use signed arithmetic in tcp_rtx_probe0_timed_out()
commit 36534d3c54537bf098224a32dc31397793d4594d upstream.

Due to timer wheel implementation, a timer will usually fire
after its schedule.

For instance, for HZ=1000, a timeout between 512ms and 4s
has a granularity of 64ms.
For this range of values, the extra delay could be up to 63ms.

For TCP, this means that tp->rcv_tstamp may be after
inet_csk(sk)->icsk_timeout whenever the timer interrupt
finally triggers, if one packet came during the extra delay.

We need to make sure tcp_rtx_probe0_timed_out() handles this case.

Fixes: e89688e3e9 ("net: tcp: fix unexcepted socket die when snd_wnd is 0")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Menglong Dong <imagedong@tencent.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20240607125652.1472540-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18 13:21:17 +02:00
Kuniyuki Iwashima c5fd77ca13 udp: Set SOCK_RCU_FREE earlier in udp_lib_get_port().
[ Upstream commit 5c0b485a8c6116516f33925b9ce5b6104a6eadfd ]

syzkaller triggered the warning [0] in udp_v4_early_demux().

In udp_v[46]_early_demux() and sk_lookup(), we do not touch the refcount
of the looked-up sk and use sock_pfree() as skb->destructor, so we check
SOCK_RCU_FREE to ensure that the sk is safe to access during the RCU grace
period.

Currently, SOCK_RCU_FREE is flagged for a bound socket after being put
into the hash table.  Moreover, the SOCK_RCU_FREE check is done too early
in udp_v[46]_early_demux() and sk_lookup(), so there could be a small race
window:

  CPU1                                 CPU2
  ----                                 ----
  udp_v4_early_demux()                 udp_lib_get_port()
  |                                    |- hlist_add_head_rcu()
  |- sk = __udp4_lib_demux_lookup()    |
  |- DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
                                       `- sock_set_flag(sk, SOCK_RCU_FREE)

We had the same bug in TCP and fixed it in commit 871019b22d1b ("net:
set SOCK_RCU_FREE before inserting socket into hashtable").

Let's apply the same fix for UDP.

[0]:
WARNING: CPU: 0 PID: 11198 at net/ipv4/udp.c:2599 udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599
Modules linked in:
CPU: 0 PID: 11198 Comm: syz-executor.1 Not tainted 6.9.0-g93bda33046e7 #13
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599
Code: c5 7a 15 fe bb 01 00 00 00 44 89 e9 31 ff d3 e3 81 e3 bf ef ff ff 89 de e8 2c 74 15 fe 85 db 0f 85 02 06 00 00 e8 9f 7a 15 fe <0f> 0b e8 98 7a 15 fe 49 8d 7e 60 e8 4f 39 2f fe 49 c7 46 60 20 52
RSP: 0018:ffffc9000ce3fa58 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8318c92c
RDX: ffff888036ccde00 RSI: ffffffff8318c2f1 RDI: 0000000000000001
RBP: ffff88805a2dd6e0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0001ffffffffffff R12: ffff88805a2dd680
R13: 0000000000000007 R14: ffff88800923f900 R15: ffff88805456004e
FS:  00007fc449127640(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc449126e38 CR3: 000000003de4b002 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
PKRU: 55555554
Call Trace:
 <TASK>
 ip_rcv_finish_core.constprop.0+0xbdd/0xd20 net/ipv4/ip_input.c:349
 ip_rcv_finish+0xda/0x150 net/ipv4/ip_input.c:447
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ip_rcv+0x16c/0x180 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core+0xb3/0xe0 net/core/dev.c:5624
 __netif_receive_skb+0x21/0xd0 net/core/dev.c:5738
 netif_receive_skb_internal net/core/dev.c:5824 [inline]
 netif_receive_skb+0x271/0x300 net/core/dev.c:5884
 tun_rx_batched drivers/net/tun.c:1549 [inline]
 tun_get_user+0x24db/0x2c50 drivers/net/tun.c:2002
 tun_chr_write_iter+0x107/0x1a0 drivers/net/tun.c:2048
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x76f/0x8d0 fs/read_write.c:590
 ksys_write+0xbf/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x41/0x50 fs/read_write.c:652
 x64_sys_call+0xe66/0x1990 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7fc44a68bc1f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 e9 cf f5 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 3c d0 f5 ff 48
RSP: 002b:00007fc449126c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004bc050 RCX: 00007fc44a68bc1f
RDX: 0000000000000032 RSI: 00000000200000c0 RDI: 00000000000000c8
RBP: 00000000004bc050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000032 R11: 0000000000000293 R12: 0000000000000000
R13: 000000000000000b R14: 00007fc44a5ec530 R15: 0000000000000000
 </TASK>

Fixes: 6acc9b432e ("bpf: Add helper to retrieve socket in BPF")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240709191356.24010-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:21:14 +02:00
Neal Cardwell 124886cf20 tcp: fix incorrect undo caused by DSACK of TLP retransmit
[ Upstream commit 0ec986ed7bab6801faed1440e8839dcc710331ff ]

Loss recovery undo_retrans bookkeeping had a long-standing bug where a
DSACK from a spurious TLP retransmit packet could cause an erroneous
undo of a fast recovery or RTO recovery that repaired a single
really-lost packet (in a sequence range outside that of the TLP
retransmit). Basically, because the loss recovery state machine didn't
account for the fact that it sent a TLP retransmit, the DSACK for the
TLP retransmit could erroneously be implicitly be interpreted as
corresponding to the normal fast recovery or RTO recovery retransmit
that plugged a real hole, thus resulting in an improper undo.

For example, consider the following buggy scenario where there is a
real packet loss but the congestion control response is improperly
undone because of this bug:

+ send packets P1, P2, P3, P4
+ P1 is really lost
+ send TLP retransmit of P4
+ receive SACK for original P2, P3, P4
+ enter fast recovery, fast-retransmit P1, increment undo_retrans to 1
+ receive DSACK for TLP P4, decrement undo_retrans to 0, undo (bug!)
+ receive cumulative ACK for P1-P4 (fast retransmit plugged real hole)

The fix: when we initialize undo machinery in tcp_init_undo(), if
there is a TLP retransmit in flight, then increment tp->undo_retrans
so that we make sure that we receive a DSACK corresponding to the TLP
retransmit, as well as DSACKs for all later normal retransmits, before
triggering a loss recovery undo. Note that we also have to move the
line that clears tp->tlp_high_seq for RTO recovery, so that upon RTO
we remember the tp->tlp_high_seq value until tcp_init_undo() and clear
it only afterward.

Also note that the bug dates back to the original 2013 TLP
implementation, commit 6ba8a3b19e ("tcp: Tail loss probe (TLP)").

However, this patch will only compile and work correctly with kernels
that have tp->tlp_retrans, which was added only in v5.8 in 2020 in
commit 76be93fc07 ("tcp: allow at most one TLP probe per flight").
So we associate this fix with that later commit.

Fixes: 76be93fc07 ("tcp: allow at most one TLP probe per flight")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Kevin Yang <yyd@google.com>
Link: https://patch.msgid.link/20240703171246.1739561-1-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:21:12 +02:00
Shigeru Yoshida 76965648fe inet_diag: Initialize pad field in struct inet_diag_req_v2
[ Upstream commit 61cf1c739f08190a4cbf047b9fbb192a94d87e3f ]

KMSAN reported uninit-value access in raw_lookup() [1]. Diag for raw
sockets uses the pad field in struct inet_diag_req_v2 for the
underlying protocol. This field corresponds to the sdiag_raw_protocol
field in struct inet_diag_req_raw.

inet_diag_get_exact_compat() converts inet_diag_req to
inet_diag_req_v2, but leaves the pad field uninitialized. So the issue
occurs when raw_lookup() accesses the sdiag_raw_protocol field.

Fix this by initializing the pad field in
inet_diag_get_exact_compat(). Also, do the same fix in
inet_diag_dump_compat() to avoid the similar issue in the future.

[1]
BUG: KMSAN: uninit-value in raw_lookup net/ipv4/raw_diag.c:49 [inline]
BUG: KMSAN: uninit-value in raw_sock_get+0x657/0x800 net/ipv4/raw_diag.c:71
 raw_lookup net/ipv4/raw_diag.c:49 [inline]
 raw_sock_get+0x657/0x800 net/ipv4/raw_diag.c:71
 raw_diag_dump_one+0xa1/0x660 net/ipv4/raw_diag.c:99
 inet_diag_cmd_exact+0x7d9/0x980
 inet_diag_get_exact_compat net/ipv4/inet_diag.c:1404 [inline]
 inet_diag_rcv_msg_compat+0x469/0x530 net/ipv4/inet_diag.c:1426
 sock_diag_rcv_msg+0x23d/0x740 net/core/sock_diag.c:282
 netlink_rcv_skb+0x537/0x670 net/netlink/af_netlink.c:2564
 sock_diag_rcv+0x35/0x40 net/core/sock_diag.c:297
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0xe74/0x1240 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x10c6/0x1260 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x332/0x3d0 net/socket.c:745
 ____sys_sendmsg+0x7f0/0xb70 net/socket.c:2585
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2639
 __sys_sendmsg net/socket.c:2668 [inline]
 __do_sys_sendmsg net/socket.c:2677 [inline]
 __se_sys_sendmsg net/socket.c:2675 [inline]
 __x64_sys_sendmsg+0x27e/0x4a0 net/socket.c:2675
 x64_sys_call+0x135e/0x3ce0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 raw_sock_get+0x650/0x800 net/ipv4/raw_diag.c:71
 raw_diag_dump_one+0xa1/0x660 net/ipv4/raw_diag.c:99
 inet_diag_cmd_exact+0x7d9/0x980
 inet_diag_get_exact_compat net/ipv4/inet_diag.c:1404 [inline]
 inet_diag_rcv_msg_compat+0x469/0x530 net/ipv4/inet_diag.c:1426
 sock_diag_rcv_msg+0x23d/0x740 net/core/sock_diag.c:282
 netlink_rcv_skb+0x537/0x670 net/netlink/af_netlink.c:2564
 sock_diag_rcv+0x35/0x40 net/core/sock_diag.c:297
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0xe74/0x1240 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x10c6/0x1260 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x332/0x3d0 net/socket.c:745
 ____sys_sendmsg+0x7f0/0xb70 net/socket.c:2585
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2639
 __sys_sendmsg net/socket.c:2668 [inline]
 __do_sys_sendmsg net/socket.c:2677 [inline]
 __se_sys_sendmsg net/socket.c:2675 [inline]
 __x64_sys_sendmsg+0x27e/0x4a0 net/socket.c:2675
 x64_sys_call+0x135e/0x3ce0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable req.i created at:
 inet_diag_get_exact_compat net/ipv4/inet_diag.c:1396 [inline]
 inet_diag_rcv_msg_compat+0x2a6/0x530 net/ipv4/inet_diag.c:1426
 sock_diag_rcv_msg+0x23d/0x740 net/core/sock_diag.c:282

CPU: 1 PID: 8888 Comm: syz-executor.6 Not tainted 6.10.0-rc4-00217-g35bb670d65fc #32
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014

Fixes: 432490f9d4 ("net: ip, diag -- Add diag interface for raw sockets")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240703091649.111773-1-syoshida@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11 12:49:14 +02:00
Jakub Kicinski 8c2debdd17 tcp_metrics: validate source addr length
[ Upstream commit 66be40e622e177316ae81717aa30057ba9e61dff ]

I don't see anything checking that TCP_METRICS_ATTR_SADDR_IPV4
is at least 4 bytes long, and the policy doesn't have an entry
for this attribute at all (neither does it for IPv6 but v6 is
manually validated).

Reviewed-by: Eric Dumazet <edumazet@google.com>
Fixes: 3e7013ddf5 ("tcp: metrics: Allow selective get/del of tcp-metrics based on src IP")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11 12:49:12 +02:00
Neal Cardwell 8a7fc2362d UPSTREAM: tcp: fix DSACK undo in fast recovery to call tcp_try_to_open()
[ Upstream commit a6458ab7fd4f427d4f6f54380453ad255b7fde83 ]

In some production workloads we noticed that connections could
sometimes close extremely prematurely with ETIMEDOUT after
transmitting only 1 TLP and RTO retransmission (when we would normally
expect roughly tcp_retries2 = TCP_RETR2 = 15 RTOs before a connection
closes with ETIMEDOUT).

From tracing we determined that these workloads can suffer from a
scenario where in fast recovery, after some retransmits, a DSACK undo
can happen at a point where the scoreboard is totally clear (we have
retrans_out == sacked_out == lost_out == 0). In such cases, calling
tcp_try_keep_open() means that we do not execute any code path that
clears tp->retrans_stamp to 0. That means that tp->retrans_stamp can
remain erroneously set to the start time of the undone fast recovery,
even after the fast recovery is undone. If minutes or hours elapse,
and then a TLP/RTO/RTO sequence occurs, then the start_ts value in
retransmits_timed_out() (which is from tp->retrans_stamp) will be
erroneously ancient (left over from the fast recovery undone via
DSACKs). Thus this ancient tp->retrans_stamp value can cause the
connection to die very prematurely with ETIMEDOUT via
tcp_write_err().

The fix: we change DSACK undo in fast recovery (TCP_CA_Recovery) to
call tcp_try_to_open() instead of tcp_try_keep_open(). This ensures
that if no retransmits are in flight at the time of DSACK undo in fast
recovery then we properly zero retrans_stamp. Note that calling
tcp_try_to_open() is more consistent with other loss recovery
behavior, since normal fast recovery (CA_Recovery) and RTO recovery
(CA_Loss) both normally end when tp->snd_una meets or exceeds
tp->high_seq and then in tcp_fastretrans_alert() the "default" switch
case executes tcp_try_to_open(). Also note that by inspection this
change to call tcp_try_to_open() implies at least one other nice bug
fix, where now an ECE-marked DSACK that causes an undo will properly
invoke tcp_enter_cwr() rather than ignoring the ECE mark.

Fixes: c7d9d6a185 ("tcp: undo on DSACK during recovery")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11 12:49:11 +02:00
Neal Cardwell b4b26d23a1 tcp: fix tcp_rcv_fastopen_synack() to enter TCP_CA_Loss for failed TFO
[ Upstream commit 5dfe9d273932c647bdc9d664f939af9a5a398cbc ]

Testing determined that the recent commit 9e046bb111f1 ("tcp: clear
tp->retrans_stamp in tcp_rcv_fastopen_synack()") has a race, and does
not always ensure retrans_stamp is 0 after a TFO payload retransmit.

If transmit completion for the SYN+data skb happens after the client
TCP stack receives the SYNACK (which sometimes happens), then
retrans_stamp can erroneously remain non-zero for the lifetime of the
connection, causing a premature ETIMEDOUT later.

Testing and tracing showed that the buggy scenario is the following
somewhat tricky sequence:

+ Client attempts a TFO handshake. tcp_send_syn_data() sends SYN + TFO
  cookie + data in a single packet in the syn_data skb. It hands the
  syn_data skb to tcp_transmit_skb(), which makes a clone. Crucially,
  it then reuses the same original (non-clone) syn_data skb,
  transforming it by advancing the seq by one byte and removing the
  FIN bit, and enques the resulting payload-only skb in the
  sk->tcp_rtx_queue.

+ Client sets retrans_stamp to the start time of the three-way
  handshake.

+ Cookie mismatches or server has TFO disabled, and server only ACKs
  SYN.

+ tcp_ack() sees SYN is acked, tcp_clean_rtx_queue() clears
  retrans_stamp.

+ Since the client SYN was acked but not the payload, the TFO failure
  code path in tcp_rcv_fastopen_synack() tries to retransmit the
  payload skb.  However, in some cases the transmit completion for the
  clone of the syn_data (which had SYN + TFO cookie + data) hasn't
  happened.  In those cases, skb_still_in_host_queue() returns true
  for the retransmitted TFO payload, because the clone of the syn_data
  skb has not had its tx completetion.

+ Because skb_still_in_host_queue() finds skb_fclone_busy() is true,
  it sets the TSQ_THROTTLED bit and the retransmit does not happen in
  the tcp_rcv_fastopen_synack() call chain.

+ The tcp_rcv_fastopen_synack() code next implicitly assumes the
  retransmit process is finished, and sets retrans_stamp to 0 to clear
  it, but this is later overwritten (see below).

+ Later, upon tx completion, tcp_tsq_write() calls
  tcp_xmit_retransmit_queue(), which puts the retransmit in flight and
  sets retrans_stamp to a non-zero value.

+ The client receives an ACK for the retransmitted TFO payload data.

+ Since we're in CA_Open and there are no dupacks/SACKs/DSACKs/ECN to
  make tcp_ack_is_dubious() true and make us call
  tcp_fastretrans_alert() and reach a code path that clears
  retrans_stamp, retrans_stamp stays nonzero.

+ Later, if there is a TLP, RTO, RTO sequence, then the connection
  will suffer an early ETIMEDOUT due to the erroneously ancient
  retrans_stamp.

The fix: this commit refactors the code to have
tcp_rcv_fastopen_synack() retransmit by reusing the relevant parts of
tcp_simple_retransmit() that enter CA_Loss (without changing cwnd) and
call tcp_xmit_retransmit_queue(). We have tcp_simple_retransmit() and
tcp_rcv_fastopen_synack() share code in this way because in both cases
we get a packet indicating non-congestion loss (MTU reduction or TFO
failure) and thus in both cases we want to retransmit as many packets
as cwnd allows, without reducing cwnd. And given that retransmits will
set retrans_stamp to a non-zero value (and may do so in a later
calling context due to TSQ), we also want to enter CA_Loss so that we
track when all retransmitted packets are ACked and clear retrans_stamp
when that happens (to ensure later recurring RTOs are using the
correct retrans_stamp and don't declare ETIMEDOUT prematurely).

Fixes: 9e046bb111f1 ("tcp: clear tp->retrans_stamp in tcp_rcv_fastopen_synack()")
Fixes: a7abf3cd76 ("tcp: consider using standard rtx logic in tcp_rcv_fastopen_synack()")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Link: https://patch.msgid.link/20240624144323.2371403-1-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05 09:33:49 +02:00
luoxuanqiang fdae4d139f Fix race for duplicate reqsk on identical SYN
[ Upstream commit ff46e3b4421923937b7f6e44ffcd3549a074f321 ]

When bonding is configured in BOND_MODE_BROADCAST mode, if two identical
SYN packets are received at the same time and processed on different CPUs,
it can potentially create the same sk (sock) but two different reqsk
(request_sock) in tcp_conn_request().

These two different reqsk will respond with two SYNACK packets, and since
the generation of the seq (ISN) incorporates a timestamp, the final two
SYNACK packets will have different seq values.

The consequence is that when the Client receives and replies with an ACK
to the earlier SYNACK packet, we will reset(RST) it.

========================================================================

This behavior is consistently reproducible in my local setup,
which comprises:

                  | NETA1 ------ NETB1 |
PC_A --- bond --- |                    | --- bond --- PC_B
                  | NETA2 ------ NETB2 |

- PC_A is the Server and has two network cards, NETA1 and NETA2. I have
  bonded these two cards using BOND_MODE_BROADCAST mode and configured
  them to be handled by different CPU.

- PC_B is the Client, also equipped with two network cards, NETB1 and
  NETB2, which are also bonded and configured in BOND_MODE_BROADCAST mode.

If the client attempts a TCP connection to the server, it might encounter
a failure. Capturing packets from the server side reveals:

10.10.10.10.45182 > localhost: Flags [S], seq 320236027,
10.10.10.10.45182 > localhost: Flags [S], seq 320236027,
localhost > 10.10.10.10.45182: Flags [S.], seq 2967855116,
localhost > 10.10.10.10.45182: Flags [S.], seq 2967855123, <==
10.10.10.10.45182 > localhost: Flags [.], ack 4294967290,
10.10.10.10.45182 > localhost: Flags [.], ack 4294967290,
localhost > 10.10.10.10.45182: Flags [R], seq 2967855117, <==
localhost > 10.10.10.10.45182: Flags [R], seq 2967855117,

Two SYNACKs with different seq numbers are sent by localhost,
resulting in an anomaly.

========================================================================

The attempted solution is as follows:
Add a return value to inet_csk_reqsk_queue_hash_add() to confirm if the
ehash insertion is successful (Up to now, the reason for unsuccessful
insertion is that a reqsk for the same connection has already been
inserted). If the insertion fails, release the reqsk.

Due to the refcnt, Kuniyuki suggests also adding a return value check
for the DCCP module; if ehash insertion fails, indicating a successful
insertion of the same connection, simply release the reqsk as well.

Simultaneously, In the reqsk_queue_hash_req(), the start of the
req->rsk_timer is adjusted to be after successful insertion.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: luoxuanqiang <luoxuanqiang@kylinos.cn>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240621013929.1386815-1-luoxuanqiang@kylinos.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05 09:33:48 +02:00
Eric Dumazet 250fad18b0 tcp: clear tp->retrans_stamp in tcp_rcv_fastopen_synack()
commit 9e046bb111f13461d3f9331e24e974324245140e upstream.

Some applications were reporting ETIMEDOUT errors on apparently
good looking flows, according to packet dumps.

We were able to root cause the issue to an accidental setting
of tp->retrans_stamp in the following scenario:

- client sends TFO SYN with data.
- server has TFO disabled, ACKs only SYN but not payload.
- client receives SYNACK covering only SYN.
- tcp_ack() eats SYN and sets tp->retrans_stamp to 0.
- tcp_rcv_fastopen_synack() calls tcp_xmit_retransmit_queue()
  to retransmit TFO payload w/o SYN, sets tp->retrans_stamp to "now",
  but we are not in any loss recovery state.
- TFO payload is ACKed.
- we are not in any loss recovery state, and don't see any dupacks,
  so we don't get to any code path that clears tp->retrans_stamp.
- tp->retrans_stamp stays non-zero for the lifetime of the connection.
- after first RTO, tcp_clamp_rto_to_user_timeout() clamps second RTO
  to 1 jiffy due to bogus tp->retrans_stamp.
- on clamped RTO with non-zero icsk_retransmits, retransmits_timed_out()
  sets start_ts from tp->retrans_stamp from TFO payload retransmit
  hours/days ago, and computes bogus long elapsed time for loss recovery,
  and suffers ETIMEDOUT early.

Fixes: a7abf3cd76 ("tcp: consider using standard rtx logic in tcp_rcv_fastopen_synack()")
CC: stable@vger.kernel.org
Co-developed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Co-developed-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240614130615.396837-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-27 13:49:13 +02:00
Ondrej Mosnacek 08fa10b265 cipso: fix total option length computation
[ Upstream commit 9f36169912331fa035d7b73a91252d7c2512eb1a ]

As evident from the definition of ip_options_get(), the IP option
IPOPT_END is used to pad the IP option data array, not IPOPT_NOP. Yet
the loop that walks the IP options to determine the total IP options
length in cipso_v4_delopt() doesn't take IPOPT_END into account.

Fix it by recognizing the IPOPT_END value as the end of actual options.

Fixes: 014ab19a69 ("selinux: Set socket NetLabel based on connection endpoint")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27 13:49:06 +02:00
Jason Xing acdf17546e tcp: count CLOSE-WAIT sockets for TCP_MIB_CURRESTAB
[ Upstream commit a46d0ea5c94205f40ecf912d1bb7806a8a64704f ]

According to RFC 1213, we should also take CLOSE-WAIT sockets into
consideration:

  "tcpCurrEstab OBJECT-TYPE
   ...
   The number of TCP connections for which the current state
   is either ESTABLISHED or CLOSE- WAIT."

After this, CurrEstab counter will display the total number of
ESTABLISHED and CLOSE-WAIT sockets.

The logic of counting
When we increment the counter?
a) if we change the state to ESTABLISHED.
b) if we change the state from SYN-RECEIVED to CLOSE-WAIT.

When we decrement the counter?
a) if the socket leaves ESTABLISHED and will never go into CLOSE-WAIT,
say, on the client side, changing from ESTABLISHED to FIN-WAIT-1.
b) if the socket leaves CLOSE-WAIT, say, on the server side, changing
from CLOSE-WAIT to LAST-ACK.

Please note: there are two chances that old state of socket can be changed
to CLOSE-WAIT in tcp_fin(). One is SYN-RECV, the other is ESTABLISHED.
So we have to take care of the former case.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21 14:38:17 +02:00
Jakub Kicinski 50569d1294 net: tls: fix marking packets as decrypted
[ Upstream commit a535d59432370343058755100ee75ab03c0e3f91 ]

For TLS offload we mark packets with skb->decrypted to make sure
they don't escape the host without getting encrypted first.
The crypto state lives in the socket, so it may get detached
by a call to skb_orphan(). As a safety check - the egress path
drops all packets with skb->decrypted and no "crypto-safe" socket.

The skb marking was added to sendpage only (and not sendmsg),
because tls_device injected data into the TCP stack using sendpage.
This special case was missed when sendpage got folded into sendmsg.

Fixes: c5c37af6ec ("tcp: Convert do_tcp_sendpages() to use MSG_SPLICE_PAGES")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240530232607.82686-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21 14:38:16 +02:00
Eric Dumazet 5af198c387 net: fix __dst_negative_advice() race
commit 92f1655aa2b2294d0b49925f3b875a634bd3b59e upstream.

__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.

RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).

Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.

Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.

Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.

Many thanks to Clement Lecigne for tracking this issue.

This old bug became visible after the blamed commit, using UDP sockets.

Fixes: a87cb3e48e ("net: Facility to report route quality of connected sockets")
Reported-by: Clement Lecigne <clecigne@google.com>
Diagnosed-by: Clement Lecigne <clecigne@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[Lee: Stable backport]
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-16 13:47:44 +02:00
Florian Westphal 570b4c5209 netfilter: tproxy: bail out if IP has been disabled on the device
[ Upstream commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 ]

syzbot reports:
general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
[..]
RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62
Call Trace:
 nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline]
 nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168

__in_dev_get_rcu() can return NULL, so check for this.

Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com
Fixes: cc6eb43385 ("tproxy: use the interface primary IP address as a default value for --on-ip")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:12:57 +02:00
Paolo Abeni 87bdc9f6f5 net: relax socket state check at accept time.
[ Upstream commit 26afda78cda3da974fd4c287962c169e9462c495 ]

Christoph reported the following splat:

WARNING: CPU: 1 PID: 772 at net/ipv4/af_inet.c:761 __inet_accept+0x1f4/0x4a0
Modules linked in:
CPU: 1 PID: 772 Comm: syz-executor510 Not tainted 6.9.0-rc7-g7da7119fe22b #56
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:__inet_accept+0x1f4/0x4a0 net/ipv4/af_inet.c:759
Code: 04 38 84 c0 0f 85 87 00 00 00 41 c7 04 24 03 00 00 00 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ec b7 da fd <0f> 0b e9 7f fe ff ff e8 e0 b7 da fd 0f 0b e9 fe fe ff ff 89 d9 80
RSP: 0018:ffffc90000c2fc58 EFLAGS: 00010293
RAX: ffffffff836bdd14 RBX: 0000000000000000 RCX: ffff888104668000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff836bdb89 R09: fffff52000185f64
R10: dffffc0000000000 R11: fffff52000185f64 R12: dffffc0000000000
R13: 1ffff92000185f98 R14: ffff88810754d880 R15: ffff8881007b7800
FS:  000000001c772880(0000) GS:ffff88811b280000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb9fcf2e178 CR3: 00000001045d2002 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 inet_accept+0x138/0x1d0 net/ipv4/af_inet.c:786
 do_accept+0x435/0x620 net/socket.c:1929
 __sys_accept4_file net/socket.c:1969 [inline]
 __sys_accept4+0x9b/0x110 net/socket.c:1999
 __do_sys_accept net/socket.c:2016 [inline]
 __se_sys_accept net/socket.c:2013 [inline]
 __x64_sys_accept+0x7d/0x90 net/socket.c:2013
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0x100 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x4315f9
Code: fd ff 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab b4 fd ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdb26d9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: ffffffffffffffda RBX: 0000000000400300 RCX: 00000000004315f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00000000006e1018 R08: 0000000000400300 R09: 0000000000400300
R10: 0000000000400300 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000040cdf0 R14: 000000000040ce80 R15: 0000000000000055
 </TASK>

The reproducer invokes shutdown() before entering the listener status.
After commit 94062790aedb ("tcp: defer shutdown(SEND_SHUTDOWN) for
TCP_SYN_RECV sockets"), the above causes the child to reach the accept
syscall in FIN_WAIT1 status.

Eric noted we can relax the existing assertion in __inet_accept()

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/490
Suggested-by: Eric Dumazet <edumazet@google.com>
Fixes: 94062790aedb ("tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/23ab880a44d8cfd967e84de8b93dbf48848e3d8c.1716299669.git.pabeni@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:12:50 +02:00
Kuniyuki Iwashima 02261d3f9d tcp: Fix shift-out-of-bounds in dctcp_update_alpha().
[ Upstream commit 3ebc46ca8675de6378e3f8f40768e180bb8afa66 ]

In dctcp_update_alpha(), we use a module parameter dctcp_shift_g
as follows:

  alpha -= min_not_zero(alpha, alpha >> dctcp_shift_g);
  ...
  delivered_ce <<= (10 - dctcp_shift_g);

It seems syzkaller started fuzzing module parameters and triggered
shift-out-of-bounds [0] by setting 100 to dctcp_shift_g:

  memcpy((void*)0x20000080,
         "/sys/module/tcp_dctcp/parameters/dctcp_shift_g\000", 47);
  res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000080ul,
                /*flags=*/2ul, /*mode=*/0ul);
  memcpy((void*)0x20000000, "100\000", 4);
  syscall(__NR_write, /*fd=*/r[0], /*val=*/0x20000000ul, /*len=*/4ul);

Let's limit the max value of dctcp_shift_g by param_set_uint_minmax().

With this patch:

  # echo 10 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g
  # cat /sys/module/tcp_dctcp/parameters/dctcp_shift_g
  10
  # echo 11 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g
  -bash: echo: write error: Invalid argument

[0]:
UBSAN: shift-out-of-bounds in net/ipv4/tcp_dctcp.c:143:12
shift exponent 100 is too large for 32-bit type 'u32' (aka 'unsigned int')
CPU: 0 PID: 8083 Comm: syz-executor345 Not tainted 6.9.0-05151-g1b294a1f3561 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x201/0x300 lib/dump_stack.c:114
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_shift_out_of_bounds+0x346/0x3a0 lib/ubsan.c:468
 dctcp_update_alpha+0x540/0x570 net/ipv4/tcp_dctcp.c:143
 tcp_in_ack_event net/ipv4/tcp_input.c:3802 [inline]
 tcp_ack+0x17b1/0x3bc0 net/ipv4/tcp_input.c:3948
 tcp_rcv_state_process+0x57a/0x2290 net/ipv4/tcp_input.c:6711
 tcp_v4_do_rcv+0x764/0xc40 net/ipv4/tcp_ipv4.c:1937
 sk_backlog_rcv include/net/sock.h:1106 [inline]
 __release_sock+0x20f/0x350 net/core/sock.c:2983
 release_sock+0x61/0x1f0 net/core/sock.c:3549
 mptcp_subflow_shutdown+0x3d0/0x620 net/mptcp/protocol.c:2907
 mptcp_check_send_data_fin+0x225/0x410 net/mptcp/protocol.c:2976
 __mptcp_close+0x238/0xad0 net/mptcp/protocol.c:3072
 mptcp_close+0x2a/0x1a0 net/mptcp/protocol.c:3127
 inet_release+0x190/0x1f0 net/ipv4/af_inet.c:437
 __sock_release net/socket.c:659 [inline]
 sock_close+0xc0/0x240 net/socket.c:1421
 __fput+0x41b/0x890 fs/file_table.c:422
 task_work_run+0x23b/0x300 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x9c8/0x2540 kernel/exit.c:878
 do_group_exit+0x201/0x2b0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xe4/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x67/0x6f
RIP: 0033:0x7f6c2b5005b6
Code: Unable to access opcode bytes at 0x7f6c2b50058c.
RSP: 002b:00007ffe883eb948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f6c2b5862f0 RCX: 00007f6c2b5005b6
RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
RBP: 0000000000000001 R08: 00000000000000e7 R09: ffffffffffffffc0
R10: 0000000000000006 R11: 0000000000000246 R12: 00007f6c2b5862f0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
 </TASK>

Reported-by: syzkaller <syzkaller@googlegroups.com>
Reported-by: Yue Sun <samsun1006219@gmail.com>
Reported-by: xingwei lee <xrivendell7@gmail.com>
Closes: https://lore.kernel.org/netdev/CAEkJfYNJM=cw-8x7_Vmj1J6uYVCWMbbvD=EFmDPVBGpTsqOxEA@mail.gmail.com/
Fixes: e3118e8359 ("net: tcp: add DCTCP congestion control algorithm")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240517091626.32772-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:12:48 +02:00
Eric Dumazet 00bb933578 tcp: avoid premature drops in tcp_add_backlog()
[ Upstream commit ec00ed472bdb7d0af840da68c8c11bff9f4d9caa ]

While testing TCP performance with latest trees,
I saw suspect SOCKET_BACKLOG drops.

tcp_add_backlog() computes its limit with :

    limit = (u32)READ_ONCE(sk->sk_rcvbuf) +
            (u32)(READ_ONCE(sk->sk_sndbuf) >> 1);
    limit += 64 * 1024;

This does not take into account that sk->sk_backlog.len
is reset only at the very end of __release_sock().

Both sk->sk_backlog.len and sk->sk_rmem_alloc could reach
sk_rcvbuf in normal conditions.

We should double sk->sk_rcvbuf contribution in the formula
to absorb bubbles in the backlog, which happen more often
for very fast flows.

This change maintains decent protection against abuses.

Fixes: c377411f24 ("net: sk_add_backlog() take rmem_alloc into account")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240423125620.3309458-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:46 +02:00
Gabriel Krisman Bertazi 71d865be7c udp: Avoid call to compute_score on multiple sites
[ Upstream commit 50aee97d15113b95a68848db1f0cb2a6c09f753a ]

We've observed a 7-12% performance regression in iperf3 UDP ipv4 and
ipv6 tests with multiple sockets on Zen3 cpus, which we traced back to
commit f0ea27e7bf ("udp: re-score reuseport groups when connected
sockets are present").  The failing tests were those that would spawn
UDP sockets per-cpu on systems that have a high number of cpus.

Unsurprisingly, it is not caused by the extra re-scoring of the reused
socket, but due to the compiler no longer inlining compute_score, once
it has the extra call site in udp4_lib_lookup2.  This is augmented by
the "Safe RET" mitigation for SRSO, needed in our Zen3 cpus.

We could just explicitly inline it, but compute_score() is quite a large
function, around 300b.  Inlining in two sites would almost double
udp4_lib_lookup2, which is a silly thing to do just to workaround a
mitigation.  Instead, this patch shuffles the code a bit to avoid the
multiple calls to compute_score.  Since it is a static function used in
one spot, the compiler can safely fold it in, as it did before, without
increasing the text size.

With this patch applied I ran my original iperf3 testcases.  The failing
cases all looked like this (ipv4):
	iperf3 -c 127.0.0.1 --udp -4 -f K -b $R -l 8920 -t 30 -i 5 -P 64 -O 2

where $R is either 1G/10G/0 (max, unlimited).  I ran 3 times each.
baseline is v6.9-rc3. harmean == harmonic mean; CV == coefficient of
variation.

ipv4:
                 1G                10G                  MAX
	    HARMEAN  (CV)      HARMEAN  (CV)    HARMEAN     (CV)
baseline 1743852.66(0.0208) 1725933.02(0.0167) 1705203.78(0.0386)
patched  1968727.61(0.0035) 1962283.22(0.0195) 1923853.50(0.0256)

ipv6:
                 1G                10G                  MAX
	    HARMEAN  (CV)      HARMEAN  (CV)    HARMEAN     (CV)
baseline 1729020.03(0.0028) 1691704.49(0.0243) 1692251.34(0.0083)
patched  1900422.19(0.0067) 1900968.01(0.0067) 1568532.72(0.1519)

This restores the performance we had before the change above with this
benchmark.  We obviously don't expect any real impact when mitigations
are disabled, but just to be sure it also doesn't regresses:

mitigations=off ipv4:
                 1G                10G                  MAX
	    HARMEAN  (CV)      HARMEAN  (CV)    HARMEAN     (CV)
baseline 3230279.97(0.0066) 3229320.91(0.0060) 2605693.19(0.0697)
patched  3242802.36(0.0073) 3239310.71(0.0035) 2502427.19(0.0882)

Cc: Lorenz Bauer <lmb@isovalent.com>
Fixes: f0ea27e7bf ("udp: re-score reuseport groups when connected sockets are present")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:42 +02:00
Kuniyuki Iwashima 6e48faad92 tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().
[ Upstream commit f2db7230f73a80dbb179deab78f88a7947f0ab7e ]

Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique()
with nice analysis.

Since commit ec94c2696f ("tcp/dccp: avoid one atomic operation for
timewait hashdance"), inet_twsk_hashdance() sets TIME-WAIT socket's
sk_refcnt after putting it into ehash and releasing the bucket lock.

Thus, there is a small race window where other threads could try to
reuse the port during connect() and call sock_hold() in tcp_twsk_unique()
for the TIME-WAIT socket with zero refcnt.

If that happens, the refcnt taken by tcp_twsk_unique() is overwritten
and sock_put() will cause underflow, triggering a real use-after-free
somewhere else.

To avoid the use-after-free, we need to use refcount_inc_not_zero() in
tcp_twsk_unique() and give up on reusing the port if it returns false.

[0]:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110
CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1
Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023
RIP: 0010:refcount_warn_saturate+0xe5/0x110
Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8
RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027
RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0
RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0
R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84
R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0
FS:  00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0
PKRU: 55555554
Call Trace:
 <TASK>
 ? refcount_warn_saturate+0xe5/0x110
 ? __warn+0x81/0x130
 ? refcount_warn_saturate+0xe5/0x110
 ? report_bug+0x171/0x1a0
 ? refcount_warn_saturate+0xe5/0x110
 ? handle_bug+0x3c/0x80
 ? exc_invalid_op+0x17/0x70
 ? asm_exc_invalid_op+0x1a/0x20
 ? refcount_warn_saturate+0xe5/0x110
 tcp_twsk_unique+0x186/0x190
 __inet_check_established+0x176/0x2d0
 __inet_hash_connect+0x74/0x7d0
 ? __pfx___inet_check_established+0x10/0x10
 tcp_v4_connect+0x278/0x530
 __inet_stream_connect+0x10f/0x3d0
 inet_stream_connect+0x3a/0x60
 __sys_connect+0xa8/0xd0
 __x64_sys_connect+0x18/0x20
 do_syscall_64+0x83/0x170
 entry_SYSCALL_64_after_hwframe+0x78/0x80
RIP: 0033:0x7f62c11a885d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d
RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003
RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0
R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0
 </TASK>

Fixes: ec94c2696f ("tcp/dccp: avoid one atomic operation for timewait hashdance")
Reported-by: Anderson Nascimento <anderson@allelesecurity.com>
Closes: https://lore.kernel.org/netdev/37a477a6-d39e-486b-9577-3463f655a6b7@allelesecurity.com/
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240501213145.62261-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:20 +02:00
Eric Dumazet f47d0d32fa tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets
[ Upstream commit 94062790aedb505bdda209b10bea47b294d6394f ]

TCP_SYN_RECV state is really special, it is only used by
cross-syn connections, mostly used by fuzzers.

In the following crash [1], syzbot managed to trigger a divide
by zero in tcp_rcv_space_adjust()

A socket makes the following state transitions,
without ever calling tcp_init_transfer(),
meaning tcp_init_buffer_space() is also not called.

         TCP_CLOSE
connect()
         TCP_SYN_SENT
         TCP_SYN_RECV
shutdown() -> tcp_shutdown(sk, SEND_SHUTDOWN)
         TCP_FIN_WAIT1

To fix this issue, change tcp_shutdown() to not
perform a TCP_SYN_RECV -> TCP_FIN_WAIT1 transition,
which makes no sense anyway.

When tcp_rcv_state_process() later changes socket state
from TCP_SYN_RECV to TCP_ESTABLISH, then look at
sk->sk_shutdown to finally enter TCP_FIN_WAIT1 state,
and send a FIN packet from a sane socket state.

This means tcp_send_fin() can now be called from BH
context, and must use GFP_ATOMIC allocations.

[1]
divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 PID: 5084 Comm: syz-executor358 Not tainted 6.9.0-rc6-syzkaller-00022-g98369dccd2f8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
 RIP: 0010:tcp_rcv_space_adjust+0x2df/0x890 net/ipv4/tcp_input.c:767
Code: e3 04 4c 01 eb 48 8b 44 24 38 0f b6 04 10 84 c0 49 89 d5 0f 85 a5 03 00 00 41 8b 8e c8 09 00 00 89 e8 29 c8 48 0f af c3 31 d2 <48> f7 f1 48 8d 1c 43 49 8d 96 76 08 00 00 48 89 d0 48 c1 e8 03 48
RSP: 0018:ffffc900031ef3f0 EFLAGS: 00010246
RAX: 0c677a10441f8f42 RBX: 000000004fb95e7e RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000027d4b11f R08: ffffffff89e535a4 R09: 1ffffffff25e6ab7
R10: dffffc0000000000 R11: ffffffff8135e920 R12: ffff88802a9f8d30
R13: dffffc0000000000 R14: ffff88802a9f8d00 R15: 1ffff1100553f2da
FS:  00005555775c0380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1155bf2304 CR3: 000000002b9f2000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
  tcp_recvmsg_locked+0x106d/0x25a0 net/ipv4/tcp.c:2513
  tcp_recvmsg+0x25d/0x920 net/ipv4/tcp.c:2578
  inet6_recvmsg+0x16a/0x730 net/ipv6/af_inet6.c:680
  sock_recvmsg_nosec net/socket.c:1046 [inline]
  sock_recvmsg+0x109/0x280 net/socket.c:1068
  ____sys_recvmsg+0x1db/0x470 net/socket.c:2803
  ___sys_recvmsg net/socket.c:2845 [inline]
  do_recvmmsg+0x474/0xae0 net/socket.c:2939
  __sys_recvmmsg net/socket.c:3018 [inline]
  __do_sys_recvmmsg net/socket.c:3041 [inline]
  __se_sys_recvmmsg net/socket.c:3034 [inline]
  __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faeb6363db9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcc1997168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007faeb6363db9
RDX: 0000000000000001 RSI: 0000000020000bc0 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000001c
R10: 0000000000000122 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Link: https://lore.kernel.org/r/20240501125448.896529-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:20 +02:00
Paul Davey 4a9771c0fb xfrm: Preserve vlan tags for transport mode software GRO
[ Upstream commit 58fbfecab965014b6e3cc956a76b4a96265a1add ]

The software GRO path for esp transport mode uses skb_mac_header_rebuild
prior to re-injecting the packet via the xfrm_napi_dev.  This only
copies skb->mac_len bytes of header which may not be sufficient if the
packet contains 802.1Q tags or other VLAN tags.  Worse copying only the
initial header will leave a packet marked as being VLAN tagged but
without the corresponding tag leading to mangling when it is later
untagged.

The VLAN tags are important when receiving the decrypted esp transport
mode packet after GRO processing to ensure it is received on the correct
interface.

Therefore record the full mac header length in xfrm*_transport_input for
later use in corresponding xfrm*_transport_finish to copy the entire mac
header when rebuilding the mac header for GRO.  The skb->data pointer is
left pointing skb->mac_header bytes after the start of the mac header as
is expected by the network stack and network and transport header
offsets reset to this location.

Fixes: 7785bba299 ("esp: Add a software GRO codepath")
Signed-off-by: Paul Davey <paul.davey@alliedtelesis.co.nz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:20 +02:00
Richard Gobert 78b6092d78 net: gro: add flush check in udp_gro_receive_segment
[ Upstream commit 5babae777c61aa8a8679d59d3cdc54165ad96d42 ]

GRO-GSO path is supposed to be transparent and as such L3 flush checks are
relevant to all UDP flows merging in GRO. This patch uses the same logic
and code from tcp_gro_receive, terminating merge if flush is non zero.

Fixes: e20cf8d3f1 ("udp: implement GRO for plain UDP sockets.")
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:07 +02:00
Richard Gobert af276a5ac8 net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb
[ Upstream commit 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 ]

Commits a602456 ("udp: Add GRO functions to UDP socket") and 57c67ff ("udp:
additional GRO support") introduce incorrect usage of {ip,ipv6}_hdr in the
complete phase of gro. The functions always return skb->network_header,
which in the case of encapsulated packets at the gro complete phase, is
always set to the innermost L3 of the packet. That means that calling
{ip,ipv6}_hdr for skbs which completed the GRO receive phase (both in
gro_list and *_gro_complete) when parsing an encapsulated packet's _outer_
L3/L4 may return an unexpected value.

This incorrect usage leads to a bug in GRO's UDP socket lookup.
udp{4,6}_lib_lookup_skb functions use ip_hdr/ipv6_hdr respectively. These
*_hdr functions return network_header which will point to the innermost L3,
resulting in the wrong offset being used in __udp{4,6}_lib_lookup with
encapsulated packets.

This patch adds network_offset and inner_network_offset to napi_gro_cb, and
makes sure both are set correctly.

To fix the issue, network_offsets union is used inside napi_gro_cb, in
which both the outer and the inner network offsets are saved.

Reproduction example:

Endpoint configuration example (fou + local address bind)

    # ip fou add port 6666 ipproto 4
    # ip link add name tun1 type ipip remote 2.2.2.1 local 2.2.2.2 encap fou encap-dport 5555 encap-sport 6666 mode ipip
    # ip link set tun1 up
    # ip a add 1.1.1.2/24 dev tun1

Netperf TCP_STREAM result on net-next before patch is applied:

net-next main, GRO enabled:
    $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5
    Recv   Send    Send
    Socket Socket  Message  Elapsed
    Size   Size    Size     Time     Throughput
    bytes  bytes   bytes    secs.    10^6bits/sec

    131072  16384  16384    5.28        2.37

net-next main, GRO disabled:
    $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5
    Recv   Send    Send
    Socket Socket  Message  Elapsed
    Size   Size    Size     Time     Throughput
    bytes  bytes   bytes    secs.    10^6bits/sec

    131072  16384  16384    5.01     2745.06

patch applied, GRO enabled:
    $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5
    Recv   Send    Send
    Socket Socket  Message  Elapsed
    Size   Size    Size     Time     Throughput
    bytes  bytes   bytes    secs.    10^6bits/sec

    131072  16384  16384    5.01     2877.38

Fixes: a6024562ff ("udp: Add GRO functions to UDP socket")
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:07 +02:00
Shigeru Yoshida 5db08343dd ipv4: Fix uninit-value access in __ip_make_skb()
[ Upstream commit fc1092f51567277509563800a3c56732070b6aa4 ]

KMSAN reported uninit-value access in __ip_make_skb() [1].  __ip_make_skb()
tests HDRINCL to know if the skb has icmphdr. However, HDRINCL can cause a
race condition. If calling setsockopt(2) with IP_HDRINCL changes HDRINCL
while __ip_make_skb() is running, the function will access icmphdr in the
skb even if it is not included. This causes the issue reported by KMSAN.

Check FLOWI_FLAG_KNOWN_NH on fl4->flowi4_flags instead of testing HDRINCL
on the socket.

Also, fl4->fl4_icmp_type and fl4->fl4_icmp_code are not initialized. These
are union in struct flowi4 and are implicitly initialized by
flowi4_init_output(), but we should not rely on specific union layout.

Initialize these explicitly in raw_sendmsg().

[1]
BUG: KMSAN: uninit-value in __ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481
 __ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481
 ip_finish_skb include/net/ip.h:243 [inline]
 ip_push_pending_frames+0x4c/0x5c0 net/ipv4/ip_output.c:1508
 raw_sendmsg+0x2381/0x2690 net/ipv4/raw.c:654
 inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x274/0x3c0 net/socket.c:745
 __sys_sendto+0x62c/0x7b0 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0x130/0x200 net/socket.c:2199
 do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3804 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc_node+0x5f6/0xc50 mm/slub.c:3888
 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:577
 __alloc_skb+0x35a/0x7c0 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1318 [inline]
 __ip_append_data+0x49ab/0x68c0 net/ipv4/ip_output.c:1128
 ip_append_data+0x1e7/0x260 net/ipv4/ip_output.c:1365
 raw_sendmsg+0x22b1/0x2690 net/ipv4/raw.c:648
 inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x274/0x3c0 net/socket.c:745
 __sys_sendto+0x62c/0x7b0 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0x130/0x200 net/socket.c:2199
 do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

CPU: 1 PID: 15709 Comm: syz-executor.7 Not tainted 6.8.0-11567-gb3603fcb79b1 #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014

Fixes: 99e5acae19 ("ipv4: Fix potential uninit variable access bug in __ip_make_skb()")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Link: https://lore.kernel.org/r/20240430123945.2057348-1-syoshida@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:07 +02:00
Yick Xie 1d2809e5d9 udp: preserve the connected status if only UDP cmsg
commit 680d11f6e5427b6af1321932286722d24a8b16c1 upstream.

If "udp_cmsg_send()" returned 0 (i.e. only UDP cmsg),
"connected" should not be set to 0. Otherwise it stops
the connected socket from using the cached route.

Fixes: 2e8de85763 ("udp: add gso segment cmsg")
Signed-off-by: Yick Xie <yick.xie@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20240418170610.867084-1-yick.xie@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-02 16:32:46 +02:00
Eric Dumazet 8240c7308c ipv4: check for NULL idev in ip_route_use_hint()
[ Upstream commit 58a4c9b1e5a3e53c9148e80b90e1e43897ce77d1 ]

syzbot was able to trigger a NULL deref in fib_validate_source()
in an old tree [1].

It appears the bug exists in latest trees.

All calls to __in_dev_get_rcu() must be checked for a NULL result.

[1]
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 2 PID: 3257 Comm: syz-executor.3 Not tainted 5.10.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
 RIP: 0010:fib_validate_source+0xbf/0x15a0 net/ipv4/fib_frontend.c:425
Code: 18 f2 f2 f2 f2 42 c7 44 20 23 f3 f3 f3 f3 48 89 44 24 78 42 c6 44 20 27 f3 e8 5d 88 48 fc 4c 89 e8 48 c1 e8 03 48 89 44 24 18 <42> 80 3c 20 00 74 08 4c 89 ef e8 d2 15 98 fc 48 89 5c 24 10 41 bf
RSP: 0018:ffffc900015fee40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88800f7a4000 RCX: ffff88800f4f90c0
RDX: 0000000000000000 RSI: 0000000004001eac RDI: ffff8880160c64c0
RBP: ffffc900015ff060 R08: 0000000000000000 R09: ffff88800f7a4000
R10: 0000000000000002 R11: ffff88800f4f90c0 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88800f7a4000
FS:  00007f938acfe6c0(0000) GS:ffff888058c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f938acddd58 CR3: 000000001248e000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ip_route_use_hint+0x410/0x9b0 net/ipv4/route.c:2231
  ip_rcv_finish_core+0x2c4/0x1a30 net/ipv4/ip_input.c:327
  ip_list_rcv_finish net/ipv4/ip_input.c:612 [inline]
  ip_sublist_rcv+0x3ed/0xe50 net/ipv4/ip_input.c:638
  ip_list_rcv+0x422/0x470 net/ipv4/ip_input.c:673
  __netif_receive_skb_list_ptype net/core/dev.c:5572 [inline]
  __netif_receive_skb_list_core+0x6b1/0x890 net/core/dev.c:5620
  __netif_receive_skb_list net/core/dev.c:5672 [inline]
  netif_receive_skb_list_internal+0x9f9/0xdc0 net/core/dev.c:5764
  netif_receive_skb_list+0x55/0x3e0 net/core/dev.c:5816
  xdp_recv_frames net/bpf/test_run.c:257 [inline]
  xdp_test_run_batch net/bpf/test_run.c:335 [inline]
  bpf_test_run_xdp_live+0x1818/0x1d00 net/bpf/test_run.c:363
  bpf_prog_test_run_xdp+0x81f/0x1170 net/bpf/test_run.c:1376
  bpf_prog_test_run+0x349/0x3c0 kernel/bpf/syscall.c:3736
  __sys_bpf+0x45c/0x710 kernel/bpf/syscall.c:5115
  __do_sys_bpf kernel/bpf/syscall.c:5201 [inline]
  __se_sys_bpf kernel/bpf/syscall.c:5199 [inline]
  __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5199

Fixes: 02b2494161 ("ipv4: use dst hint for ipv4 list receive")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240421184326.1704930-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-02 16:32:36 +02:00
Eric Dumazet d68dc711d8 icmp: prevent possible NULL dereferences from icmp_build_probe()
[ Upstream commit c58e88d49097bd12dfcfef4f075b43f5d5830941 ]

First problem is a double call to __in_dev_get_rcu(), because
the second one could return NULL.

if (__in_dev_get_rcu(dev) && __in_dev_get_rcu(dev)->ifa_list)

Second problem is a read from dev->ip6_ptr with no NULL check:

if (!list_empty(&rcu_dereference(dev->ip6_ptr)->addr_list))

Use the correct RCU API to fix these.

v2: add missing include <net/addrconf.h>

Fixes: d329ea5bd8 ("icmp: add response to RFC 8335 PROBE messages")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Andreas Roeseler <andreas.a.roeseler@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-02 16:32:35 +02:00
Eric Dumazet 89242d9584 netfilter: complete validation of user input
[ Upstream commit 65acf6e0501ac8880a4f73980d01b5d27648b956 ]

In my recent commit, I missed that do_replace() handlers
use copy_from_sockptr() (which I fixed), followed
by unsafe copy_from_sockptr_offset() calls.

In all functions, we can perform the @optlen validation
before even calling xt_alloc_table_info() with the following
check:

if ((u64)optlen < (u64)tmp.size + sizeof(tmp))
        return -EINVAL;

Fixes: 0c83842df40f ("netfilter: validate user input for expected length")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-17 11:19:30 +02:00
Arnd Bergmann 5fd0b8b486 ipv4/route: avoid unused-but-set-variable warning
[ Upstream commit cf1b7201df59fb936f40f4a807433fe3f2ce310a ]

The log_martians variable is only used in an #ifdef, causing a 'make W=1'
warning with gcc:

net/ipv4/route.c: In function 'ip_rt_send_redirect':
net/ipv4/route.c:880:13: error: variable 'log_martians' set but not used [-Werror=unused-but-set-variable]

Change the #ifdef to an equivalent IS_ENABLED() to let the compiler
see where the variable is used.

Fixes: 30038fc61a ("net: ip_rt_send_redirect() optimization")
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240408074219.3030256-2-arnd@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-17 11:19:29 +02:00
Eric Dumazet a7b862abe4 net: add netdev_lockdep_set_classes() to virtual drivers
[ Upstream commit 0bef512012b1cd8820f0c9ec80e5f8ceb43fdd59 ]

Based on a syzbot report, it appears many virtual
drivers do not yet use netdev_lockdep_set_classes(),
triggerring lockdep false positives.

WARNING: possible recursive locking detected
6.8.0-rc4-next-20240212-syzkaller #0 Not tainted

syz-executor.0/19016 is trying to acquire lock:
 ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline]
 ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340

but task is already holding lock:
 ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline]
 ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
  lock(_xmit_ETHER#2);
  lock(_xmit_ETHER#2);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

9 locks held by syz-executor.0/19016:
  #0: ffffffff8f385208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
  #0: ffffffff8f385208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6603
  #1: ffffc90000a08c00 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1697
  #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
  #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
  #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1360 net/ipv4/ip_output.c:228
  #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
  #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
  #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4284
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline]
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:195 [inline]
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3771 [inline]
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3b10 net/core/dev.c:4325
  #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline]
  #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340
  #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
  #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
  #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1360 net/ipv4/ip_output.c:228
  #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
  #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
  #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4284
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline]
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:195 [inline]
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3771 [inline]
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3b10 net/core/dev.c:4325

stack backtrace:
CPU: 1 PID: 19016 Comm: syz-executor.0 Not tainted 6.8.0-rc4-next-20240212-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <IRQ>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
  check_deadlock kernel/locking/lockdep.c:3062 [inline]
  validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
  __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
  lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
  __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
  _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:351 [inline]
  __netif_tx_lock include/linux/netdevice.h:4452 [inline]
  sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340
  __dev_xmit_skb net/core/dev.c:3784 [inline]
  __dev_queue_xmit+0x1912/0x3b10 net/core/dev.c:4325
  neigh_output include/net/neighbour.h:542 [inline]
  ip_finish_output2+0xe66/0x1360 net/ipv4/ip_output.c:235
  iptunnel_xmit+0x540/0x9b0 net/ipv4/ip_tunnel_core.c:82
  ip_tunnel_xmit+0x20ee/0x2960 net/ipv4/ip_tunnel.c:831
  erspan_xmit+0x9de/0x1460 net/ipv4/ip_gre.c:720
  __netdev_start_xmit include/linux/netdevice.h:4989 [inline]
  netdev_start_xmit include/linux/netdevice.h:5003 [inline]
  xmit_one net/core/dev.c:3555 [inline]
  dev_hard_start_xmit+0x242/0x770 net/core/dev.c:3571
  sch_direct_xmit+0x2b6/0x5f0 net/sched/sch_generic.c:342
  __dev_xmit_skb net/core/dev.c:3784 [inline]
  __dev_queue_xmit+0x1912/0x3b10 net/core/dev.c:4325
  neigh_output include/net/neighbour.h:542 [inline]
  ip_finish_output2+0xe66/0x1360 net/ipv4/ip_output.c:235
  igmpv3_send_cr net/ipv4/igmp.c:723 [inline]
  igmp_ifc_timer_expire+0xb71/0xd90 net/ipv4/igmp.c:813
  call_timer_fn+0x17e/0x600 kernel/time/timer.c:1700
  expire_timers kernel/time/timer.c:1751 [inline]
  __run_timers+0x621/0x830 kernel/time/timer.c:2038
  run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2051
  __do_softirq+0x2bc/0x943 kernel/softirq.c:554
  invoke_softirq kernel/softirq.c:428 [inline]
  __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
  irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1076 [inline]
  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1076
 </IRQ>
 <TASK>
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 RIP: 0010:resched_offsets_ok kernel/sched/core.c:10127 [inline]
 RIP: 0010:__might_resched+0x16f/0x780 kernel/sched/core.c:10142
Code: 00 4c 89 e8 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df 48 89 44 24 38 0f b6 04 10 84 c0 0f 85 87 04 00 00 41 8b 45 00 c1 e0 08 <01> d8 44 39 e0 0f 85 d6 00 00 00 44 89 64 24 1c 48 8d bc 24 a0 00
RSP: 0018:ffffc9000ee069e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880296a9e00
RDX: dffffc0000000000 RSI: ffff8880296a9e00 RDI: ffffffff8bfe8fa0
RBP: ffffc9000ee06b00 R08: ffffffff82326877 R09: 1ffff11002b5ad1b
R10: dffffc0000000000 R11: ffffed1002b5ad1c R12: 0000000000000000
R13: ffff8880296aa23c R14: 000000000000062a R15: 1ffff92001dc0d44
  down_write+0x19/0x50 kernel/locking/rwsem.c:1578
  kernfs_activate fs/kernfs/dir.c:1403 [inline]
  kernfs_add_one+0x4af/0x8b0 fs/kernfs/dir.c:819
  __kernfs_create_file+0x22e/0x2e0 fs/kernfs/file.c:1056
  sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:307
  create_files fs/sysfs/group.c:64 [inline]
  internal_create_group+0x4f4/0xf20 fs/sysfs/group.c:152
  internal_create_groups fs/sysfs/group.c:192 [inline]
  sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:218
  create_dir lib/kobject.c:78 [inline]
  kobject_add_internal+0x472/0x8d0 lib/kobject.c:240
  kobject_add_varg lib/kobject.c:374 [inline]
  kobject_init_and_add+0x124/0x190 lib/kobject.c:457
  netdev_queue_add_kobject net/core/net-sysfs.c:1706 [inline]
  netdev_queue_update_kobjects+0x1f3/0x480 net/core/net-sysfs.c:1758
  register_queue_kobjects net/core/net-sysfs.c:1819 [inline]
  netdev_register_kobject+0x265/0x310 net/core/net-sysfs.c:2059
  register_netdevice+0x1191/0x19c0 net/core/dev.c:10298
  bond_newlink+0x3b/0x90 drivers/net/bonding/bond_netlink.c:576
  rtnl_newlink_create net/core/rtnetlink.c:3506 [inline]
  __rtnl_newlink net/core/rtnetlink.c:3726 [inline]
  rtnl_newlink+0x158f/0x20a0 net/core/rtnetlink.c:3739
  rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6606
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
  netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
  netlink_sendmsg+0xa3c/0xd70 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  __sys_sendto+0x3a4/0x4f0 net/socket.c:2191
  __do_sys_sendto net/socket.c:2203 [inline]
  __se_sys_sendto net/socket.c:2199 [inline]
  __x64_sys_sendto+0xde/0x100 net/socket.c:2199
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc3fa87fa9c

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240212140700.2795436-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-13 13:07:30 +02:00
Antoine Tenart 03b6f3692b udp: prevent local UDP tunnel packets from being GROed
commit 64235eabc4b5b18c507c08a1f16cdac6c5661220 upstream.

GRO has a fundamental issue with UDP tunnel packets as it can't detect
those in a foolproof way and GRO could happen before they reach the
tunnel endpoint. Previous commits have fixed issues when UDP tunnel
packets come from a remote host, but if those packets are issued locally
they could run into checksum issues.

If the inner packet has a partial checksum the information will be lost
in the GRO logic, either in udp4/6_gro_complete or in
udp_gro_complete_segment and packets will have an invalid checksum when
leaving the host.

Prevent local UDP tunnel packets from ever being GROed at the outer UDP
level.

Due to skb->encapsulation being wrongly used in some drivers this is
actually only preventing UDP tunnel packets with a partial checksum to
be GROed (see iptunnel_handle_offloads) but those were also the packets
triggering issues so in practice this should be sufficient.

Fixes: 9fd1ff5d2a ("udp: Support UDP fraglist GRO/GSO.")
Fixes: 36707061d6 ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets")
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:35:54 +02:00
Antoine Tenart 2a1b61d0cb udp: do not transition UDP GRO fraglist partial checksums to unnecessary
commit f0b8c30345565344df2e33a8417a27503589247d upstream.

UDP GRO validates checksums and in udp4/6_gro_complete fraglist packets
are converted to CHECKSUM_UNNECESSARY to avoid later checks. However
this is an issue for CHECKSUM_PARTIAL packets as they can be looped in
an egress path and then their partial checksums are not fixed.

Different issues can be observed, from invalid checksum on packets to
traces like:

  gen01: hw csum failure
  skb len=3008 headroom=160 headlen=1376 tailroom=0
  mac=(106,14) net=(120,40) trans=160
  shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
  csum(0xffff232e ip_summed=2 complete_sw=0 valid=0 level=0)
  hash(0x77e3d716 sw=1 l4=1) proto=0x86dd pkttype=0 iif=12
  ...

Fix this by only converting CHECKSUM_NONE packets to
CHECKSUM_UNNECESSARY by reusing __skb_incr_checksum_unnecessary. All
other checksum types are kept as-is, including CHECKSUM_COMPLETE as
fraglist packets being segmented back would have their skb->csum valid.

Fixes: 9fd1ff5d2a ("udp: Support UDP fraglist GRO/GSO.")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:35:53 +02:00
Antoine Tenart 3001e7aa43 udp: do not accept non-tunnel GSO skbs landing in a tunnel
commit 3d010c8031e39f5fa1e8b13ada77e0321091011f upstream.

When rx-udp-gro-forwarding is enabled UDP packets might be GROed when
being forwarded. If such packets might land in a tunnel this can cause
various issues and udp_gro_receive makes sure this isn't the case by
looking for a matching socket. This is performed in
udp4/6_gro_lookup_skb but only in the current netns. This is an issue
with tunneled packets when the endpoint is in another netns. In such
cases the packets will be GROed at the UDP level, which leads to various
issues later on. The same thing can happen with rx-gro-list.

We saw this with geneve packets being GROed at the UDP level. In such
case gso_size is set; later the packet goes through the geneve rx path,
the geneve header is pulled, the offset are adjusted and frag_list skbs
are not adjusted with regard to geneve. When those skbs hit
skb_fragment, it will misbehave. Different outcomes are possible
depending on what the GROed skbs look like; from corrupted packets to
kernel crashes.

One example is a BUG_ON[1] triggered in skb_segment while processing the
frag_list. Because gso_size is wrong (geneve header was pulled)
skb_segment thinks there is "geneve header size" of data in frag_list,
although it's in fact the next packet. The BUG_ON itself has nothing to
do with the issue. This is only one of the potential issues.

Looking up for a matching socket in udp_gro_receive is fragile: the
lookup could be extended to all netns (not speaking about performances)
but nothing prevents those packets from being modified in between and we
could still not find a matching socket. It's OK to keep the current
logic there as it should cover most cases but we also need to make sure
we handle tunnel packets being GROed too early.

This is done by extending the checks in udp_unexpected_gso: GSO packets
lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits and landing in a tunnel must
be segmented.

[1] kernel BUG at net/core/skbuff.c:4408!
    RIP: 0010:skb_segment+0xd2a/0xf70
    __udp_gso_segment+0xaa/0x560

Fixes: 9fd1ff5d2a ("udp: Support UDP fraglist GRO/GSO.")
Fixes: 36707061d6 ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:35:53 +02:00