[net?] KCSAN: data-race in xfrm_lookup_with_ifid / xfrm_lookup_with_ifid (6)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 78b421b6a7c6 Merge tag 'linux-watchdog-6.4-rc1' of git://w..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15a92388280000
kernel config: https://syzkaller.appspot.com/x/.config?x=5ca69f42875812f0
dashboard link: https://syzkaller.appspot.com/bug?extid=309b956f6ae6d848a475
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [da...@davemloft.net edum...@google.com her...@gondor.apana.org.au ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org pab...@redhat.com steffen....@secunet.com]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f02c65b80263/disk-78b421b6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cc4e86c68fe6/vmlinux-78b421b6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/71a31c122401/bzImage-78b421b6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+309b95...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in xfrm_lookup_with_ifid / xfrm_lookup_with_ifid

write to 0xffff888178040d08 of 8 bytes by task 17440 on cpu 0:
xfrm_lookup_with_ifid+0xce7/0x12d0 net/xfrm/xfrm_policy.c:3216
xfrm_lookup net/xfrm/xfrm_policy.c:3268 [inline]
xfrm_lookup_route+0x3b/0x100 net/xfrm/xfrm_policy.c:3279
ip6_dst_lookup_flow+0x98/0xc0 net/ipv6/ip6_output.c:1246
send6+0x23c/0x3a0 drivers/net/wireguard/socket.c:139
wg_socket_send_skb_to_peer+0xbd/0x130 drivers/net/wireguard/socket.c:178
wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51
process_one_work+0x3e6/0x750 kernel/workqueue.c:2405
worker_thread+0x5f2/0xa10 kernel/workqueue.c:2552
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

write to 0xffff888178040d08 of 8 bytes by task 17429 on cpu 1:
xfrm_lookup_with_ifid+0xce7/0x12d0 net/xfrm/xfrm_policy.c:3216
xfrm_lookup net/xfrm/xfrm_policy.c:3268 [inline]
xfrm_lookup_route+0x3b/0x100 net/xfrm/xfrm_policy.c:3279
ip6_dst_lookup_flow+0x98/0xc0 net/ipv6/ip6_output.c:1246
send6+0x23c/0x3a0 drivers/net/wireguard/socket.c:139
wg_socket_send_skb_to_peer+0xbd/0x130 drivers/net/wireguard/socket.c:178
wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51
process_one_work+0x3e6/0x750 kernel/workqueue.c:2405
worker_thread+0x5f2/0xa10 kernel/workqueue.c:2552
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x00000000645555c4 -> 0x00000000645555c6

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17429 Comm: kworker/u4:8 Not tainted 6.3.0-syzkaller-13164-g78b421b6a7c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.