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KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release (6)

Status: auto-obsoleted due to no activity on 2025/05/25 10:40
Subsystems: net
[Documentation on labels]
First crash: 236d, last: 107d
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release (4) net 6 2 377d 410d 0/29 auto-obsoleted due to no activity on 2024/08/08 02:32
upstream KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release (5) net 6 4 311d 341d 0/29 auto-obsoleted due to no activity on 2024/10/12 18:17
upstream KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release (2) net 6 2 1639d 1671d 0/29 auto-closed as invalid on 2021/02/22 11:54
upstream KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release (3) net 6 1 1092d 1090d 0/29 auto-closed as invalid on 2022/08/23 20:42
upstream KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release net 6 22 1987d 2091d 0/29 auto-closed as invalid on 2020/04/15 13:52

Sample crash report:
==================================================================
BUG: KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release

write to 0xffff888151542d20 of 8 bytes by task 16032 on cpu 0:
 sk_set_socket include/net/sock.h:2006 [inline]
 sock_orphan include/net/sock.h:2025 [inline]
 sk_common_release+0xa6/0x220 net/core/sock.c:3920
 udp_lib_close+0x15/0x20 include/net/udp.h:311
 inet_release+0xce/0xf0 net/ipv4/af_inet.c:435
 inet6_release+0x3e/0x60 net/ipv6/af_inet6.c:487
 __sock_release net/socket.c:647 [inline]
 sock_close+0x68/0x150 net/socket.c:1391
 __fput+0x2ac/0x640 fs/file_table.c:465
 ____fput+0x1c/0x30 fs/file_table.c:493
 task_work_run+0x13c/0x1b0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888151542d20 of 8 bytes by task 3554 on cpu 1:
 l2tp_tunnel_del_work+0x30/0x1a0 net/l2tp/l2tp_core.c:1418
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4de/0xa20 kernel/workqueue.c:3319
 worker_thread+0x52c/0x710 kernel/workqueue.c:3400
 kthread+0x4b7/0x540 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0xffff88817bcee700 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3554 Comm: kworker/u8:54 Not tainted 6.14.0-syzkaller-10514-g7f2ff7b62617 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: l2tp l2tp_tunnel_del_work
==================================================================
IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/30 10:37 upstream 7f2ff7b62617 d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
2025/03/11 08:09 upstream 4d872d51bc9d 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
2025/02/25 22:31 upstream 2a1944bff549 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
2025/01/18 12:29 upstream 595523945be0 f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
2025/01/10 08:49 upstream 643e2e259c2b 67d7ec0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
2025/01/01 04:59 upstream ccb98ccef0e5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
2024/11/28 07:07 upstream 7d4050728c83 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
2024/11/21 17:44 upstream 43fb83c17ba2 4b25d554 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
* Struck through repros no longer work on HEAD.