Commit Graph

8 Commits

Author SHA1 Message Date
Eric Dumazet 5355ed6388 fou, fou6: avoid uninit-value in gue_err() and gue6_err()
My prior commit missed the fact that these functions
were using udp_hdr() (aka skb_transport_header())
to get access to GUE header.

Since pskb_transport_may_pull() does not exist yet, we have to add
transport_offset to our pskb_may_pull() calls.

BUG: KMSAN: uninit-value in gue_err+0x514/0xfa0 net/ipv4/fou.c:1032
CPU: 1 PID: 10648 Comm: syz-executor.1 Not tainted 5.0.0+ #11
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
 gue_err+0x514/0xfa0 net/ipv4/fou.c:1032
 __udp4_lib_err_encap_no_sk net/ipv4/udp.c:571 [inline]
 __udp4_lib_err_encap net/ipv4/udp.c:626 [inline]
 __udp4_lib_err+0x12e6/0x1d40 net/ipv4/udp.c:665
 udp_err+0x74/0x90 net/ipv4/udp.c:737
 icmp_socket_deliver net/ipv4/icmp.c:767 [inline]
 icmp_unreach+0xb65/0x1070 net/ipv4/icmp.c:884
 icmp_rcv+0x11a1/0x1950 net/ipv4/icmp.c:1066
 ip_protocol_deliver_rcu+0x584/0xbb0 net/ipv4/ip_input.c:208
 ip_local_deliver_finish net/ipv4/ip_input.c:234 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip_local_deliver+0x624/0x7b0 net/ipv4/ip_input.c:255
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:414 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip_rcv+0x6bd/0x740 net/ipv4/ip_input.c:524
 __netif_receive_skb_one_core net/core/dev.c:4973 [inline]
 __netif_receive_skb net/core/dev.c:5083 [inline]
 process_backlog+0x756/0x10e0 net/core/dev.c:5923
 napi_poll net/core/dev.c:6346 [inline]
 net_rx_action+0x78b/0x1a60 net/core/dev.c:6412
 __do_softirq+0x53f/0x93a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x214/0x250 kernel/softirq.c:416
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:536
 smp_apic_timer_interrupt+0x48/0x70 arch/x86/kernel/apic/apic.c:1064
 apic_timer_interrupt+0x2e/0x40 arch/x86/entry/entry_64.S:814
 </IRQ>
RIP: 0010:finish_lock_switch+0x2b/0x40 kernel/sched/core.c:2597
Code: 48 89 e5 53 48 89 fb e8 63 e7 95 00 8b b8 88 0c 00 00 48 8b 00 48 85 c0 75 12 48 89 df e8 dd db 95 00 c6 00 00 c6 03 00 fb 5b <5d> c3 e8 4e e6 95 00 eb e7 66 90 66 2e 0f 1f 84 00 00 00 00 00 55
RSP: 0018:ffff888081a0fc80 EFLAGS: 00000296 ORIG_RAX: ffffffffffffff13
RAX: ffff88821fd6bd80 RBX: ffff888027898000 RCX: ccccccccccccd000
RDX: ffff88821fca8d80 RSI: ffff888000000000 RDI: 00000000000004a0
RBP: ffff888081a0fc80 R08: 0000000000000002 R09: ffff888081a0fb08
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88811130e388 R14: ffff88811130da00 R15: ffff88812fdb7d80
 finish_task_switch+0xfc/0x2d0 kernel/sched/core.c:2698
 context_switch kernel/sched/core.c:2851 [inline]
 __schedule+0x6cc/0x800 kernel/sched/core.c:3491
 schedule+0x15b/0x240 kernel/sched/core.c:3535
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x2ba/0x980 kernel/time/hrtimer.c:1679
 hrtimer_nanosleep kernel/time/hrtimer.c:1733 [inline]
 __do_sys_nanosleep kernel/time/hrtimer.c:1767 [inline]
 __se_sys_nanosleep+0x746/0x960 kernel/time/hrtimer.c:1754
 __x64_sys_nanosleep+0x3e/0x60 kernel/time/hrtimer.c:1754
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x4855a0
Code: 00 00 48 c7 c0 d4 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb be 66 0f 1f 44 00 00 83 3d b1 11 5d 00 00 75 14 b8 23 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 04 e2 f8 ff c3 48 83 ec 08 e8 3a 55 fd ff
RSP: 002b:0000000000a4fd58 EFLAGS: 00000246 ORIG_RAX: 0000000000000023
RAX: ffffffffffffffda RBX: 0000000000085780 RCX: 00000000004855a0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000a4fd60
RBP: 00000000000007ec R08: 0000000000000001 R09: 0000000000ceb940
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 0000000000a4fdb0 R14: 0000000000085711 R15: 0000000000a4fdc0

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159
 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185
 slab_post_alloc_hook mm/slab.h:445 [inline]
 slab_alloc_node mm/slub.c:2773 [inline]
 __kmalloc_node_track_caller+0xe9e/0xff0 mm/slub.c:4398
 __kmalloc_reserve net/core/skbuff.c:140 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1012 [inline]
 alloc_skb_with_frags+0x186/0xa60 net/core/skbuff.c:5287
 sock_alloc_send_pskb+0xafd/0x10a0 net/core/sock.c:2091
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2108
 __ip_append_data+0x34cd/0x5000 net/ipv4/ip_output.c:998
 ip_append_data+0x324/0x480 net/ipv4/ip_output.c:1220
 icmp_push_reply+0x23d/0x7e0 net/ipv4/icmp.c:375
 __icmp_send+0x2ea3/0x30f0 net/ipv4/icmp.c:737
 icmp_send include/net/icmp.h:47 [inline]
 ipv4_link_failure+0x6d/0x230 net/ipv4/route.c:1190
 dst_link_failure include/net/dst.h:427 [inline]
 arp_error_report+0x106/0x1a0 net/ipv4/arp.c:297
 neigh_invalidate+0x359/0x8e0 net/core/neighbour.c:992
 neigh_timer_handler+0xdf2/0x1280 net/core/neighbour.c:1078
 call_timer_fn+0x285/0x600 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1362 [inline]
 __run_timers+0xdb4/0x11d0 kernel/time/timer.c:1681
 run_timer_softirq+0x2e/0x50 kernel/time/timer.c:1694
 __do_softirq+0x53f/0x93a kernel/softirq.c:293

Fixes: 26fc181e6c ("fou, fou6: do not assume linear skbs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-08 15:19:53 -08:00
Paolo Abeni 5de362df44 fou6: fix proto error handler argument type
Last argument of gue6_err_proto_handler() has a wrong type annotation,
fix it and make sparse happy again.

Fixes: b8a51b38e4 ("fou, fou6: ICMP error handlers for FoU and GUE")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-22 16:05:11 -08:00
Eric Dumazet 26fc181e6c fou, fou6: do not assume linear skbs
Both gue_err() and gue6_err() incorrectly assume
linear skbs. Fix them to use pskb_may_pull().

BUG: KMSAN: uninit-value in gue6_err+0x475/0xc40 net/ipv6/fou6.c:101
CPU: 0 PID: 18083 Comm: syz-executor1 Not tainted 5.0.0-rc1+ #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
 gue6_err+0x475/0xc40 net/ipv6/fou6.c:101
 __udp6_lib_err_encap_no_sk net/ipv6/udp.c:434 [inline]
 __udp6_lib_err_encap net/ipv6/udp.c:491 [inline]
 __udp6_lib_err+0x18d0/0x2590 net/ipv6/udp.c:522
 udplitev6_err+0x118/0x130 net/ipv6/udplite.c:27
 icmpv6_notify+0x462/0x9f0 net/ipv6/icmp.c:784
 icmpv6_rcv+0x18ac/0x3fa0 net/ipv6/icmp.c:872
 ip6_protocol_deliver_rcu+0xb5a/0x23a0 net/ipv6/ip6_input.c:394
 ip6_input_finish net/ipv6/ip6_input.c:434 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip6_input+0x2b6/0x350 net/ipv6/ip6_input.c:443
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x4e7/0x6d0 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ipv6_rcv+0x34b/0x3f0 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4973 [inline]
 __netif_receive_skb net/core/dev.c:5083 [inline]
 process_backlog+0x756/0x10e0 net/core/dev.c:5923
 napi_poll net/core/dev.c:6346 [inline]
 net_rx_action+0x78b/0x1a60 net/core/dev.c:6412
 __do_softirq+0x53f/0x93a kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1039
 </IRQ>
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x16f/0x1a0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:696 [inline]
 ip6_finish_output2+0x1d64/0x25f0 net/ipv6/ip6_output.c:121
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip6_output+0x5ca/0x710 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:444 [inline]
 ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:176
 ip6_send_skb+0xfa/0x390 net/ipv6/ip6_output.c:1727
 udp_v6_send_skb+0x1733/0x1d20 net/ipv6/udp.c:1169
 udpv6_sendmsg+0x424e/0x45d0 net/ipv6/udp.c:1466
 inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xdb9/0x11b0 net/socket.c:2116
 __sys_sendmmsg+0x580/0xad0 net/socket.c:2211
 __do_sys_sendmmsg net/socket.c:2240 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2237
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2237
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457ec9
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4a5204fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457ec9
RDX: 00000000040001ab RSI: 0000000020000240 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4a520506d4
R13: 00000000004c4ce5 R14: 00000000004d85d8 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159
 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2754 [inline]
 __kmalloc_node_track_caller+0xe9e/0xff0 mm/slub.c:4377
 __kmalloc_reserve net/core/skbuff.c:140 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1012 [inline]
 alloc_skb_with_frags+0x1c7/0xac0 net/core/skbuff.c:5288
 sock_alloc_send_pskb+0xafd/0x10a0 net/core/sock.c:2091
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2108
 __ip6_append_data+0x42ed/0x5dc0 net/ipv6/ip6_output.c:1443
 ip6_append_data+0x3c2/0x650 net/ipv6/ip6_output.c:1619
 icmp6_send+0x2f5c/0x3c40 net/ipv6/icmp.c:574
 icmpv6_send+0xe5/0x110 net/ipv6/ip6_icmp.c:43
 ip6_link_failure+0x5c/0x2c0 net/ipv6/route.c:2231
 dst_link_failure include/net/dst.h:427 [inline]
 vti_xmit net/ipv4/ip_vti.c:229 [inline]
 vti_tunnel_xmit+0xf3b/0x1ea0 net/ipv4/ip_vti.c:265
 __netdev_start_xmit include/linux/netdevice.h:4382 [inline]
 netdev_start_xmit include/linux/netdevice.h:4391 [inline]
 xmit_one net/core/dev.c:3278 [inline]
 dev_hard_start_xmit+0x604/0xc40 net/core/dev.c:3294
 __dev_queue_xmit+0x2e48/0x3b80 net/core/dev.c:3864
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3897
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1511
 neigh_output include/net/neighbour.h:508 [inline]
 ip6_finish_output2+0x1d4e/0x25f0 net/ipv6/ip6_output.c:120
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip6_output+0x5ca/0x710 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:444 [inline]
 ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:176
 ip6_send_skb+0xfa/0x390 net/ipv6/ip6_output.c:1727
 udp_v6_send_skb+0x1733/0x1d20 net/ipv6/udp.c:1169
 udpv6_sendmsg+0x424e/0x45d0 net/ipv6/udp.c:1466
 inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xdb9/0x11b0 net/socket.c:2116
 __sys_sendmmsg+0x580/0xad0 net/socket.c:2211
 __do_sys_sendmmsg net/socket.c:2240 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2237
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2237
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Fixes: b8a51b38e4 ("fou, fou6: ICMP error handlers for FoU and GUE")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-15 22:01:31 -08:00
Stefano Brivio 44039e0017 fou6: Prevent unbounded recursion in GUE error handler
I forgot to deal with IPv6 in commit 11789039da ("fou: Prevent unbounded
recursion in GUE error handler").

Now syzbot reported what might be the same type of issue, caused by
gue6_err(), that is, handling exceptions for direct UDP encapsulation in
GUE (UDP-in-UDP) leads to unbounded recursion in the GUE exception
handler.

As it probably doesn't make sense to set up GUE this way, and it's
currently not even possible to configure this, skip exception handling for
UDP (or UDP-Lite) packets encapsulated in UDP (or UDP-Lite) packets with
GUE on IPv6.

Reported-by: syzbot+4ad25edc7a33e4ab91e0@syzkaller.appspotmail.com
Reported-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: b8a51b38e4 ("fou, fou6: ICMP error handlers for FoU and GUE")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-04 13:06:07 -08:00
Stefano Brivio b8a51b38e4 fou, fou6: ICMP error handlers for FoU and GUE
As the destination port in FoU and GUE receiving sockets doesn't
necessarily match the remote destination port, we can't associate errors
to the encapsulating tunnels with a socket lookup -- we need to blindly
try them instead. This means we don't even know if we are handling errors
for FoU or GUE without digging into the packets.

Hence, implement a single handler for both, one for IPv4 and one for IPv6,
that will check whether the packet that generated the ICMP error used a
direct IP encapsulation or if it had a GUE header, and send the error to
the matching protocol handler, if any.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08 17:13:08 -08:00
stephen hemminger 9dc621afa8 fou: make local function static
The build header functions are not used by any other code.

net/ipv6/fou6.c:36:5: warning: no previous prototype for ‘fou6_build_header’ [-Wmissing-prototypes]
net/ipv6/fou6.c:54:5: warning: no previous prototype for ‘gue6_build_header’ [-Wmissing-prototypes]

Need to do some code rearranging to satisfy different Kconfig possiblities.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-21 13:42:36 -04:00
Arnd Bergmann fabb13db44 fou: add Kconfig options for IPv6 support
A previous patch added the fou6.ko module, but that failed to link
in a couple of configurations:

net/built-in.o: In function `ip6_tnl_encap_add_fou_ops':
net/ipv6/fou6.c:88: undefined reference to `ip6_tnl_encap_add_ops'
net/ipv6/fou6.c:94: undefined reference to `ip6_tnl_encap_add_ops'
net/ipv6/fou6.c:97: undefined reference to `ip6_tnl_encap_del_ops'
net/built-in.o: In function `ip6_tnl_encap_del_fou_ops':
net/ipv6/fou6.c:106: undefined reference to `ip6_tnl_encap_del_ops'
net/ipv6/fou6.c:107: undefined reference to `ip6_tnl_encap_del_ops'

If CONFIG_IPV6=m, ip6_tnl_encap_add_ops/ip6_tnl_encap_del_ops
are in a module, but fou6.c can still be built-in, and that
obviously fails to link.

Also, if CONFIG_IPV6=y, but CONFIG_IPV6_TUNNEL=m or
CONFIG_IPV6_TUNNEL=n, the same problem happens for a different
reason.

This adds two new silent Kconfig symbols to work around both
problems:

- CONFIG_IPV6_FOU is now always set to 'm' if either CONFIG_NET_FOU=m
  or CONFIG_IPV6=m
- CONFIG_IPV6_FOU_TUNNEL is set implicitly when IPV6_FOU is enabled
  and NET_FOU_IP_TUNNELS is also turned out, and it will ensure
  that CONFIG_IPV6_TUNNEL is also available.

The options could be made user-visible as well, to give additional
room for configuration, but it seems easier not to bother users
with more choice here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: aa3463d65e ("fou: Add encap ops for IPv6 tunnels")
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-29 22:24:21 -07:00
Tom Herbert aa3463d65e fou: Add encap ops for IPv6 tunnels
This patch add a new fou6 module that provides encapsulation
operations for IPv6.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 18:03:16 -04:00