nft_*.c files whose NFT_EXPR_STATEFUL flag is set on need to
use __GFP_ACCOUNT flag for objects that are dynamically
allocated from the packet path.
Such objects are allocated inside nft_expr_ops->init() callbacks
executed in task context while processing netlink messages.
In addition, this patch adds accounting to nft_set_elem_expr_clone()
used for the same purposes.
Signed-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The `nft_bitwise_reduce` and `nft_bitwise_fast_reduce` functions should
compare the bitwise operation in `expr` with the tracked operation
associated with the destination register of `expr`. However, instead of
being called on `expr` and `track->regs[priv->dreg].selector`,
`nft_expr_priv` is called on `expr` twice, so both reduce functions
return true even when the operations differ.
Fixes: be5650f8f4 ("netfilter: nft_bitwise: track register operations")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Incorrect output device in nf_egress hook, from Phill Sutter.
2) Preserve liberal flag in TCP conntrack state, reported by Sven Auhagen.
3) Use GFP_KERNEL_ACCOUNT flag for nf_tables objects, from Vasily Averin.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
nftables replaces iptables, but it lacks memcg accounting.
This patch account most of the memory allocation associated with nft
and should protect the host from misusing nft inside a memcg restricted
container.
Signed-off-by: Vasily Averin <vvs@openvz.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Do not reset IP_CT_TCP_FLAG_BE_LIBERAL flag in out-of-sync scenarios
coming before the TCP window tracking, otherwise such connections will
fail in the window check.
Update tcp_options() to leave this flag in place and add a new helper
function to reset the tcp window state.
Based on patch from Sven Auhagen.
Fixes: c4832c7bbc ("netfilter: nf_ct_tcp: improve out-of-sync situation in TCP tracking")
Tested-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2022-03-21 v2
We've added 137 non-merge commits during the last 17 day(s) which contain
a total of 143 files changed, 7123 insertions(+), 1092 deletions(-).
The main changes are:
1) Custom SEC() handling in libbpf, from Andrii.
2) subskeleton support, from Delyan.
3) Use btf_tag to recognize __percpu pointers in the verifier, from Hao.
4) Fix net.core.bpf_jit_harden race, from Hou.
5) Fix bpf_sk_lookup remote_port on big-endian, from Jakub.
6) Introduce fprobe (multi kprobe) _without_ arch bits, from Masami.
The arch specific bits will come later.
7) Introduce multi_kprobe bpf programs on top of fprobe, from Jiri.
8) Enable non-atomic allocations in local storage, from Joanne.
9) Various var_off ptr_to_btf_id fixed, from Kumar.
10) bpf_ima_file_hash helper, from Roberto.
11) Add "live packet" mode for XDP in BPF_PROG_RUN, from Toke.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (137 commits)
selftests/bpf: Fix kprobe_multi test.
Revert "rethook: x86: Add rethook x86 implementation"
Revert "arm64: rethook: Add arm64 rethook implementation"
Revert "powerpc: Add rethook support"
Revert "ARM: rethook: Add rethook arm implementation"
bpftool: Fix a bug in subskeleton code generation
bpf: Fix bpf_prog_pack when PMU_SIZE is not defined
bpf: Fix bpf_prog_pack for multi-node setup
bpf: Fix warning for cast from restricted gfp_t in verifier
bpf, arm: Fix various typos in comments
libbpf: Close fd in bpf_object__reuse_map
bpftool: Fix print error when show bpf map
bpf: Fix kprobe_multi return probe backtrace
Revert "bpf: Add support to inline bpf_get_func_ip helper on x86"
bpf: Simplify check in btf_parse_hdr()
selftests/bpf/test_lirc_mode2.sh: Exit with proper code
bpf: Check for NULL return from bpf_get_btf_vmlinux
selftests/bpf: Test skipping stacktrace
bpf: Adjust BPF stack helper functions to accommodate skip > 0
bpf: Select proper size for bpf_prog_pack
...
====================
Link: https://lore.kernel.org/r/20220322050159.5507-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The flowtable object is already passed as argument to
nf_flow_table_iterate(), do use not data pointer to pass flowtable.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if we can elide the load. Cancel if the new candidate
isn't identical to previous store.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The fib expression stores to a register, so we can't add empty stub.
Check that the register that is being written is in fact redundant.
In most cases, this is expected to cancel tracking as re-use is
unlikely.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this
tunnel expression performs. This allows to skip this redundant operation.
If the destination contains a different selector, update the register
tracking information. This patch does not perform bitwise tracking.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this
xfrm expression performs. This allows to skip this redundant operation.
If the destination contains a different selector, update the register
tracking information.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this
socket expression performs. This allows to skip this redundant
operation. If the destination contains a different selector, update the
register tracking information.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The immediate expression might clobber existing data on the registers,
cancel register tracking for the destination register.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this
osf expression performs. Always cancel register tracking for jhash since
this requires tracking multiple source registers in case of
concatenations. Perform register tracking (without bitwise) for symhash
since input does not come from source register.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Allow to recycle the previous output of the OS fingerprint expression
if flags and ttl are the same.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Random and increment are stateful, each invocation results in fresh output.
Cancel register tracking for these two expressions.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
its enough to export the meta get reduce helper and then call it
from nft_meta_bridge too.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In most cases, nft_lookup will be read-only, i.e. won't clobber
registers. In case of map, we need to cancel the registers that will
see stores.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this ct
expression performs. This allows to skip this redundant operation. If
the destination contains a different selector, update the register
tracking information.
Export nft_expr_reduce_bitwise as a symbol since nft_ct might be
compiled as a module.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Output of expressions might be larger than one single register, this might
clobber existing data. Reset tracking for all destination registers that
required to store the expression output.
This patch adds three new helper functions:
- nft_reg_track_update: cancel previous register tracking and update it.
- nft_reg_track_cancel: cancel any previous register tracking info.
- __nft_reg_track_cancel: cancel only one single register tracking info.
Partial register clobbering detection is also supported by checking the
.num_reg field which describes the number of register that are used.
This patch updates the following expressions:
- meta_bridge
- bitwise
- byteorder
- meta
- payload
to use these helper functions.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Skip register tracking for expressions that perform read-only operations
on the registers. Define and use a cookie pointer NFT_REDUCE_READONLY to
avoid defining stubs for these expressions.
This patch re-enables register tracking which was disabled in ed5f85d422
("netfilter: nf_tables: disable register tracking"). Follow up patches
add remaining register tracking for existing expressions.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The function sets the pernet boolean to avoid the spurious warning from
nf_ct_lookup_helper() when assigning conntrack helpers via nftables.
Fixes: 1a64edf54f ("netfilter: nft_ct: add helper set support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
as of commit 4608fdfc07
("netfilter: conntrack: collect all entries in one cycle")
conntrack gc was changed to run every 2 minutes.
On systems where conntrack hash table is set to large value, most evictions
happen from gc worker rather than the packet path due to hash table
distribution.
This causes netlink event overflows when events are collected.
This change collects average expiry of scanned entries and
reschedules to the average remaining value, within 1 to 60 second interval.
To avoid event overflows, reschedule after each bucket and add a
limit for both run time and number of evictions per run.
If more entries have to be evicted, reschedule and restart 1 jiffy
into the future.
Reported-by: Karel Rericha <karel@maxtel.cz>
Cc: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Cc: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Bail out in case userspace uses unsupported registers.
Fixes: 49499c3e6e ("netfilter: nf_tables: switch registers to 32 bit addressing")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_flow_offload_inet_hook() does not check for 802.1q and PPPoE.
Fetch inner ethertype from these encapsulation protocols.
Fixes: 72efd585f7 ("netfilter: flowtable: add pppoe support")
Fixes: 4cd91f7c29 ("netfilter: flowtable: add vlan support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
1) Revert CHECKSUM_UNNECESSARY for UDP packet from conntrack.
2) Reject unsupported families when creating tables, from Phil Sutter.
3) GRE support for the flowtable, from Toshiaki Makita.
4) Add GRE offload support for act_ct, also from Toshiaki.
5) Update mlx5 driver to support for GRE flowtable offload,
from Toshiaki Makita.
6) Oneliner to clean up incorrect indentation in nf_conntrack_bridge,
from Jiapeng Chong.
* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: bridge: clean up some inconsistent indenting
net/mlx5: Support GRE conntrack offload
act_ct: Support GRE offload
netfilter: flowtable: Support GRE
netfilter: nf_tables: Reject tables of unsupported family
Revert "netfilter: conntrack: mark UDP zero checksum as CHECKSUM_UNNECESSARY"
====================
Link: https://lore.kernel.org/r/20220315091513.66544-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The register tracking infrastructure is incomplete, it might lead to
generating incorrect ruleset bytecode, disable it by now given we are
late in the release process.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This was a prerequisite for the ill-fated
"netfilter: nat: force port remap to prevent shadowing well-known ports".
As this has been reverted, this change can be backed out too.
Signed-off-by: Florian Westphal <fw@strlen.de>
This reverts commit 878aed8db3.
This change breaks existing setups where conntrack is used with
asymmetric paths.
In these cases, the NAT transformation occurs on the syn-ack instead of
the syn:
1. SYN x:12345 -> y -> 443 // sent by initiator, receiverd by responder
2. SYNACK y:443 -> x:12345 // First packet seen by conntrack, as sent by responder
3. tuple_force_port_remap() gets called, sees:
'tcp from 443 to port 12345 NAT' -> pick a new source port, inititor receives
4. SYNACK y:$RANDOM -> x:12345 // connection is never established
While its possible to avoid the breakage with NOTRACK rules, a kernel
update should not break working setups.
An alternative to the revert is to augment conntrack to tag
mid-stream connections plus more code in the nat core to skip NAT
for such connections, however, this leads to more interaction/integration
between conntrack and NAT.
Therefore, revert, users will need to add explicit nat rules to avoid
port shadowing.
Link: https://lore.kernel.org/netfilter-devel/20220302105908.GA5852@breakpoint.cc/#R
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2051413
Signed-off-by: Florian Westphal <fw@strlen.de>
Currently, -Wmissing-prototypes warning is ignored for GCC, but not
clang. This leads to clang build warning in W=1 mode. Since the flag
used by both compilers is same, we can use the unified __diag_ignore_all
macro that works for all supported versions and compilers which have
__diag macro support (currently GCC >= 8.0, and Clang >= 11.0).
Also add nf_conntrack_bpf.h include to prevent missing prototype warning
for register_nf_conntrack_bpf.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220304224645.3677453-8-memxor@gmail.com
If skb has the (rcv) timestamp available, nfnetlink_{log, queue}.c
logs/outputs it to the userspace. When the locally generated skb is
looping from egress to ingress over a virtual interface (e.g. veth,
loopback...), skb->tstamp may have the delivery time before it is
known that will be delivered locally and received by another sk. Like
handling the delivery time in network tapping, use ktime_get_real() to
get the (rcv) timestamp. The earlier added helper skb_tstamp_cond() is
used to do this. false is passed to the second 'cond' arg such
that doing ktime_get_real() or not only depends on the
netstamp_needed_key static key.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Right now, skb->tstamp is reset to 0 whenever the skb is forwarded.
If skb->tstamp has the mono delivery_time, clearing it can hurt
the performance when it finally transmits out to fq@phy-dev.
The earlier patch added a skb->mono_delivery_time bit to
flag the skb->tstamp carrying the mono delivery_time.
This patch adds skb_clear_tstamp() helper which keeps
the mono delivery_time and clears everything else.
The delivery_time clearing will be postponed until the stack knows the
skb will be delivered locally. It will be done in a latter patch.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An nftables family is merely a hollow container, its family just a
number and such not reliant on compile-time options other than nftables
support itself. Add an artificial check so attempts at using a family
the kernel can't support fail as early as possible. This helps user
space detect kernels which lack e.g. NFPROTO_INET.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This reverts commit 5bed9f3f63.
Gal Presman says:
this patch broke geneve tunnels, or possibly all udp tunnels?
A simple test that creates two geneve tunnels and runs tcp iperf fails
and results in checksum errors (TcpInCsumErrors).
Original commit wanted to fix nf_reject with zero checksum,
so it appears better to change nf reject infra instead.
Fixes: 5bed9f3f63 ("netfilter: conntrack: mark UDP zero checksum as CHECKSUM_UNNECESSARY")
Reported-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
After cited commit optimizted hw insertion, flow table entries are
populated with ifindex information which was intended to only be used
for HW offload. This tuple ifindex is hashed in the flow table key, so
it must be filled for lookup to be successful. But tuple ifindex is only
relevant for the netfilter flowtables (nft), so it's not filled in
act_ct flow table lookup, resulting in lookup failure, and no SW
offload and no offload teardown for TCP connection FIN/RST packets.
To fix this, add new tc ifindex field to tuple, which will
only be used for offloading, not for lookup, as it will not be
part of the tuple hash.
Fixes: 9795ded7f9 ("net/sched: act_ct: Fill offloading tuple iifidx")
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In case someone combines bpf socket assign and nf_queue, then we will
queue an skb who references a struct sock that did not have its
reference count incremented.
As we leave rcu protection, there is no guarantee that skb->sk is still
valid.
For refcount-less skb->sk case, try to increment the reference count
and then override the destructor.
In case of failure we have two choices: orphan the skb and 'delete'
preselect or let nf_queue() drop the packet.
Do the latter, it should not happen during normal operation.
Fixes: cf7fbe660f ("bpf: Add socket assign support")
Acked-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Florian Westphal <fw@strlen.de>
Eric Dumazet says:
The sock_hold() side seems suspect, because there is no guarantee
that sk_refcnt is not already 0.
On failure, we cannot queue the packet and need to indicate an
error. The packet will be dropped by the caller.
v2: split skb prefetch hunk into separate change
Fixes: 271b72c7fa ("udp: RCU handling for Unicast packets.")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
There is no guarantee that state->sk refers to a full socket.
If refcount transitions to 0, sock_put calls sk_free which then ends up
with garbage fields.
I'd like to thank Oleksandr Natalenko and Jiri Benc for considerable
debug work and pointing out state->sk oddities.
Fixes: ca6fb06518 ("tcp: attach SYNACK messages to request sockets instead of listener")
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
While kfree_rcu(ptr) _is_ supported, it has some limitations.
Given that 99.99% of kfree_rcu() users [1] use the legacy
two parameters variant, and @catchall objects do have an rcu head,
simply use it.
Choice of kfree_rcu(ptr) variant was probably not intentional.
[1] including calls from net/netfilter/nf_tables_api.c
Fixes: aaa31047a6 ("netfilter: nftables: add catch-all set element support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
stateful objects can be updated from the control plane.
The transaction logic allocates a temporary object for this purpose.
The ->init function was called for this object, so plain kfree() leaks
resources. We must call ->destroy function of the object.
nft_obj_destroy does this, but it also decrements the module refcount,
but the update path doesn't increment it.
To avoid special-casing the update object release, do module_get for
the update case too and release it via nft_obj_destroy().
Fixes: d62d0ba97b ("netfilter: nf_tables: Introduce stateful object update operation")
Cc: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We need to provide a destroy callback to release the extra fields.
Fixes: 3b9e2ea6c1 ("netfilter: nft_limit: move stateful fields out of expression data")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Unregister flowtable hooks before they are releases via
nf_tables_flowtable_destroy() otherwise hook core reports UAF.
BUG: KASAN: use-after-free in nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142
Read of size 4 at addr ffff8880736f7438 by task syz-executor579/3666
CPU: 0 PID: 3666 Comm: syz-executor579 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
__dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106
dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106
print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
__kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450
kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450
nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142
__nf_register_net_hook+0x27e/0x8d0 net/netfilter/core.c:429 net/netfilter/core.c:429
nf_register_net_hook+0xaa/0x180 net/netfilter/core.c:571 net/netfilter/core.c:571
nft_register_flowtable_net_hooks+0x3c5/0x730 net/netfilter/nf_tables_api.c:7232 net/netfilter/nf_tables_api.c:7232
nf_tables_newflowtable+0x2022/0x2cf0 net/netfilter/nf_tables_api.c:7430 net/netfilter/nf_tables_api.c:7430
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline]
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] net/netfilter/nfnetlink.c:652
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] net/netfilter/nfnetlink.c:652
nfnetlink_rcv+0x10e6/0x2550 net/netfilter/nfnetlink.c:652 net/netfilter/nfnetlink.c:652
__nft_release_hook() calls nft_unregister_flowtable_net_hooks() which
only unregisters the hooks, then after RCU grace period, it is
guaranteed that no packets add new entries to the flowtable (no flow
offload rules and flowtable hooks are reachable from packet path), so it
is safe to call nf_flow_table_free() which cleans up the remaining
entries from the flowtable (both software and hardware) and it unbinds
the flow_block.
Fixes: ff4bf2f42a ("netfilter: nf_tables: add nft_unregister_flowtable_hook()")
Reported-by: syzbot+e918523f77e62790d6d9@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Vasily Averin