[moderation] [wireguard?] KCSAN: data-race in wg_socket_set_peer_endpoint / wg_socket_set_peer_endpoint (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 40fbbd64bba6 Merge tag 'pull-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1612922a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b319ff1b6a2797ca
dashboard link: https://syzkaller.appspot.com/bug?extid=dd0dccb9fba80e33b63d
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [Ja...@zx2c4.com andrew...@lunn.ch da...@davemloft.net edum...@google.com ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org pab...@redhat.com wire...@lists.zx2c4.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2a45b42079bb/disk-40fbbd64.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/17b8e7ccd251/vmlinux-40fbbd64.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5676c9d986c0/bzImage-40fbbd64.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dd0dcc...@syzkaller.appspotmail.com

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

read to 0xffff88811a54c108 of 2 bytes by task 3488 on cpu 0:
endpoint_eq drivers/net/wireguard/socket.c:265 [inline]
wg_socket_set_peer_endpoint+0x61/0x440 drivers/net/wireguard/socket.c:281
wg_socket_set_peer_endpoint_from_skb+0x6d/0xa0 drivers/net/wireguard/socket.c:305
wg_receive_handshake_packet drivers/net/wireguard/receive.c:150 [inline]
wg_packet_handshake_receive_worker+0x3c4/0x5d0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
worker_thread+0x582/0x770 kernel/workqueue.c:3421
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

write to 0xffff88811a54c108 of 16 bytes by task 23 on cpu 1:
wg_socket_set_peer_endpoint+0x3b6/0x440 drivers/net/wireguard/socket.c:285
wg_socket_set_peer_endpoint_from_skb+0x6d/0xa0 drivers/net/wireguard/socket.c:305
wg_receive_handshake_packet drivers/net/wireguard/receive.c:172 [inline]
wg_packet_handshake_receive_worker+0x3f1/0x5d0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
worker_thread+0x582/0x770 kernel/workqueue.c:3421
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 23 Comm: kworker/1:0 Tainted: G W syzkaller #0 PREEMPT(voluntary)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker
==================================================================


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