linux/include
Eric Dumazet 802a7dc5cf netfilter: conntrack: annotate data-races around ct->timeout
(struct nf_conn)->timeout can be read/written locklessly,
add READ_ONCE()/WRITE_ONCE() to prevent load/store tearing.

BUG: KCSAN: data-race in __nf_conntrack_alloc / __nf_conntrack_find_get

write to 0xffff888132e78c08 of 4 bytes by task 6029 on cpu 0:
 __nf_conntrack_alloc+0x158/0x280 net/netfilter/nf_conntrack_core.c:1563
 init_conntrack+0x1da/0xb30 net/netfilter/nf_conntrack_core.c:1635
 resolve_normal_ct+0x502/0x610 net/netfilter/nf_conntrack_core.c:1746
 nf_conntrack_in+0x1c5/0x88f net/netfilter/nf_conntrack_core.c:1901
 ipv6_conntrack_local+0x19/0x20 net/netfilter/nf_conntrack_proto.c:414
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_slow+0x72/0x170 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:262 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0xa3a/0xa60 net/ipv6/ip6_output.c:324
 inet6_csk_xmit+0x1a2/0x1e0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x132a/0x1840 net/ipv4/tcp_output.c:1402
 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline]
 tcp_write_xmit+0x1450/0x4460 net/ipv4/tcp_output.c:2680
 __tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2864
 tcp_push_pending_frames include/net/tcp.h:1897 [inline]
 tcp_data_snd_check+0x62/0x2e0 net/ipv4/tcp_input.c:5452
 tcp_rcv_established+0x880/0x10e0 net/ipv4/tcp_input.c:5947
 tcp_v6_do_rcv+0x36e/0xa50 net/ipv6/tcp_ipv6.c:1521
 sk_backlog_rcv include/net/sock.h:1030 [inline]
 __release_sock+0xf2/0x270 net/core/sock.c:2768
 release_sock+0x40/0x110 net/core/sock.c:3300
 sk_stream_wait_memory+0x435/0x700 net/core/stream.c:145
 tcp_sendmsg_locked+0xb85/0x25a0 net/ipv4/tcp.c:1402
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1440
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 __sys_sendto+0x21e/0x2c0 net/socket.c:2036
 __do_sys_sendto net/socket.c:2048 [inline]
 __se_sys_sendto net/socket.c:2044 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2044
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888132e78c08 of 4 bytes by task 17446 on cpu 1:
 nf_ct_is_expired include/net/netfilter/nf_conntrack.h:286 [inline]
 ____nf_conntrack_find net/netfilter/nf_conntrack_core.c:776 [inline]
 __nf_conntrack_find_get+0x1c7/0xac0 net/netfilter/nf_conntrack_core.c:807
 resolve_normal_ct+0x273/0x610 net/netfilter/nf_conntrack_core.c:1734
 nf_conntrack_in+0x1c5/0x88f net/netfilter/nf_conntrack_core.c:1901
 ipv6_conntrack_local+0x19/0x20 net/netfilter/nf_conntrack_proto.c:414
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_slow+0x72/0x170 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:262 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0xa3a/0xa60 net/ipv6/ip6_output.c:324
 inet6_csk_xmit+0x1a2/0x1e0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x132a/0x1840 net/ipv4/tcp_output.c:1402
 __tcp_send_ack+0x1fd/0x300 net/ipv4/tcp_output.c:3956
 tcp_send_ack+0x23/0x30 net/ipv4/tcp_output.c:3962
 __tcp_ack_snd_check+0x2d8/0x510 net/ipv4/tcp_input.c:5478
 tcp_ack_snd_check net/ipv4/tcp_input.c:5523 [inline]
 tcp_rcv_established+0x8c2/0x10e0 net/ipv4/tcp_input.c:5948
 tcp_v6_do_rcv+0x36e/0xa50 net/ipv6/tcp_ipv6.c:1521
 sk_backlog_rcv include/net/sock.h:1030 [inline]
 __release_sock+0xf2/0x270 net/core/sock.c:2768
 release_sock+0x40/0x110 net/core/sock.c:3300
 tcp_sendpage+0x94/0xb0 net/ipv4/tcp.c:1114
 inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833
 rds_tcp_xmit+0x376/0x5f0 net/rds/tcp_send.c:118
 rds_send_xmit+0xbed/0x1500 net/rds/send.c:367
 rds_send_worker+0x43/0x200 net/rds/threads.c:200
 process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
 worker_thread+0x616/0xa70 kernel/workqueue.c:2445
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

value changed: 0x00027cc2 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17446 Comm: kworker/u4:5 Tainted: G        W         5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krdsd rds_send_worker

Note: I chose an arbitrary commit for the Fixes: tag,
because I do not think we need to backport this fix to very old kernels.

Fixes: e37542ba11 ("netfilter: conntrack: avoid possible false sharing")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-12-08 01:29:15 +01:00
..
acpi Merge branches 'acpica', 'acpi-ec', 'acpi-pmic' and 'acpi-video' 2021-11-10 14:03:14 +01:00
asm-generic Add linux/cacheflush.h 2021-11-17 10:36:15 -05:00
clocksource ARM: 2021-11-02 11:24:14 -07:00
crypto crypto: ecc - Export additional helper functions 2021-10-29 21:04:03 +08:00
drm Removed the TTM Huge Page functionnality to address a crash, a timeout 2021-11-11 08:14:19 +10:00
dt-bindings dt-bindings: Rename Ingenic CGU headers to ingenic,*.h 2021-11-11 22:27:14 -06:00
keys
kunit include/kunit/test.h: replace kernel.h with the necessary inclusions 2021-11-09 10:02:49 -08:00
kvm
linux siphash: use _unaligned version by default 2021-11-29 19:50:50 -08:00
math-emu
media Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
memory
misc
net netfilter: conntrack: annotate data-races around ct->timeout 2021-12-08 01:29:15 +01:00
pcmcia
ras
rdma RDMA/netlink: Add __maybe_unused to static inline in C file 2021-11-16 13:13:08 -04:00
scsi SCSI misc on 20211112 2021-11-12 12:25:50 -08:00
soc net: mscc: ocelot: create a function that replaces an existing VCAP filter 2021-11-26 11:38:20 -08:00
sound Revert "ALSA: memalloc: Convert x86 SG-buffer handling with non-contiguous type" 2021-11-04 22:10:03 +01:00
target
trace f2fs-for-5.16-rc1 2021-11-13 11:20:22 -08:00
uapi virtio-mem: support VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE 2021-11-13 13:14:05 -08:00
vdso
video
xen xen: add "not_essential" flag to struct xenbus_driver 2021-11-23 13:41:29 -06:00