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KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer (6)

Status: auto-obsoleted due to no activity on 2025/11/04 23:24
Subsystems: wireguard
[Documentation on labels]
First crash: 153d, last: 71d
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer (3) wireguard 6 6 472d 530d 0/29 auto-obsoleted due to no activity on 2024/09/08 23:48
upstream KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer wireguard 6 1 817d 814d 0/29 auto-obsoleted due to no activity on 2023/09/29 08:20
upstream KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer (2) wireguard 6 1 716d 712d 0/29 auto-obsoleted due to no activity on 2024/01/08 19:50
upstream KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer (5) wireguard 6 3 256d 286d 0/29 auto-obsoleted due to no activity on 2025/05/03 20:15
upstream KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer (4) wireguard 6 3 381d 426d 0/29 auto-obsoleted due to no activity on 2024/12/29 16:46

Sample crash report:
==================================================================
BUG: KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer

read-write to 0xffff888119d909c8 of 8 bytes by task 4999 on cpu 1:
 wg_socket_send_skb_to_peer+0xe8/0x130 drivers/net/wireguard/socket.c:183
 wg_socket_send_buffer_to_peer+0xf1/0x120 drivers/net/wireguard/socket.c:200
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
 wg_packet_handshake_send_worker+0x10d/0x160 drivers/net/wireguard/send.c:51
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff888119d909c8 of 8 bytes by task 3392 on cpu 0:
 wg_socket_send_skb_to_peer+0xe8/0x130 drivers/net/wireguard/socket.c:183
 wg_socket_send_buffer_to_peer+0xf1/0x120 drivers/net/wireguard/socket.c:200
 wg_packet_send_handshake_response+0xe6/0x120 drivers/net/wireguard/send.c:103
 wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline]
 wg_packet_handshake_receive_worker+0x3e1/0x5d0 drivers/net/wireguard/receive.c:213
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000000000000 -> 0x0000000000000094

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3392 Comm: kworker/0:3 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/09 23:21 upstream 9dd1835ecda5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer
2025/07/23 01:18 upstream 89be9a83ccf1 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer
2025/06/20 00:45 upstream 24770983ccfe ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wg_socket_send_skb_to_peer / wg_socket_send_skb_to_peer
* Struck through repros no longer work on HEAD.