syzbot


KCSAN: data-race in copy_process / free_pid (14)

Status: moderation: reported on 2025/01/04 00:52
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+fab52e3459fa2f95df57@syzkaller.appspotmail.com
First crash: 146d, last: 1d03h
Discussions (2)
Title Replies (including bot) Last reply
[PATCH v2] pid: annotate data-races around pid_ns->pid_allocated 4 (4) 2025/04/28 08:30
[PATCH v1] pid: annotate data-races around pid_ns->pid_allocated 7 (7) 2025/04/25 05:37
Similar bugs (13)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in copy_process / free_pid (8) kernel 1 903d 903d 0/28 auto-obsoleted due to no activity on 2023/01/17 03:08
upstream KCSAN: data-race in copy_process / free_pid (11) kernel 1 369d 369d 0/28 auto-obsoleted due to no activity on 2024/06/30 01:30
upstream KCSAN: data-race in copy_process / free_pid kernel 1 1995d 1995d 0/28 auto-closed as invalid on 2020/02/20 19:37
upstream KCSAN: data-race in copy_process / free_pid (10) kernel 23 408d 537d 0/28 auto-obsoleted due to no activity on 2024/05/21 14:09
upstream KCSAN: data-race in copy_process / free_pid (9) kernel 12 652d 738d 0/28 auto-obsoleted due to no activity on 2023/09/21 05:02
upstream KCSAN: data-race in copy_process / free_pid (6) kernel 2 1094d 1097d 0/28 auto-closed as invalid on 2022/07/06 07:38
upstream KCSAN: data-race in copy_process / free_pid (4) kernel 1 1398d 1398d 0/28 auto-closed as invalid on 2021/09/04 11:26
upstream KCSAN: data-race in copy_process / free_pid (5) kernel 32 1234d 1353d 0/28 auto-closed as invalid on 2022/02/15 18:33
upstream KCSAN: data-race in copy_process / free_pid (2) kasan 1 1910d 1910d 0/28 auto-closed as invalid on 2020/05/15 22:36
upstream KCSAN: data-race in copy_process / free_pid (7) kernel 4 993d 1045d 0/28 auto-obsoleted due to no activity on 2022/10/14 18:22
upstream KCSAN: data-race in copy_process / free_pid (13) kernel 6 224d 258d 0/28 auto-obsoleted due to no activity on 2024/11/22 02:42
upstream KCSAN: data-race in copy_process / free_pid (3) kernel 1 1589d 1589d 0/28 auto-closed as invalid on 2021/02/26 04:07
upstream KCSAN: data-race in copy_process / free_pid (12) kernel 1 327d 327d 0/28 auto-obsoleted due to no activity on 2024/08/11 08:23

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

read-write to 0xffffffff86860980 of 4 bytes by task 37 on cpu 1:
 free_pid+0x77/0x180 kernel/pid.c:126
 free_pids+0x7a/0xb0 kernel/pid.c:159
 release_task+0x9a9/0xb60 kernel/exit.c:295
 wait_task_zombie kernel/exit.c:1270 [inline]
 wait_consider_task+0x113f/0x1650 kernel/exit.c:1497
 do_wait_pid kernel/exit.c:1636 [inline]
 __do_wait+0x34a/0x510 kernel/exit.c:1671
 do_wait+0xb7/0x260 kernel/exit.c:1712
 kernel_wait+0x51/0xc0 kernel/exit.c:1888
 call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
 call_usermodehelper_exec_work+0x9c/0x160 kernel/umh.c:163
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x486/0x510 kernel/kthread.c:464
 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 to 0xffffffff86860980 of 4 bytes by task 31 on cpu 0:
 copy_process+0x148f/0x1fe0 kernel/fork.c:2602
 kernel_clone+0x16c/0x5b0 kernel/fork.c:2859
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2937
 call_usermodehelper_exec_sync kernel/umh.c:132 [inline]
 call_usermodehelper_exec_work+0x7a/0x160 kernel/umh.c:163
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x486/0x510 kernel/kthread.c:464
 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: 0x80000092 -> 0x80000091

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 31 Comm: kworker/u8:1 Not tainted 6.15.0-syzkaller-07774-g90b83efa6701 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound call_usermodehelper_exec_work
==================================================================

Crashes (48):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/29 06:50 upstream 90b83efa6701 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/29 05:18 upstream 3d413f0cfd7e 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/27 16:02 upstream 785cdec46e92 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/26 00:09 upstream 0f8c0258bf04 2d4582d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/24 20:29 upstream b1427432d3b6 ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/24 09:55 upstream 4856ebd99715 ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/23 10:02 upstream 94305e83eccb fa44301a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/22 20:13 upstream 5cdb2c77c4c3 0919b50b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/20 23:17 upstream a5806cd506af b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/18 22:59 upstream a5806cd506af f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/18 04:52 upstream 5723cc3450bc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/16 10:31 upstream fee3e843b309 cfde8269 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/15 16:33 upstream 088d13246a46 cfde8269 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/14 11:49 upstream 9f35e33144ae 7344edeb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/14 00:30 upstream 405e6c37c89e 7344edeb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/13 07:41 upstream e9565e23cd89 f6671af7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/12 15:13 upstream cd802e7e5f1e 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/10 04:25 upstream 0e1329d4045c 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/08 16:13 upstream d76bb1ebb558 dbf35fa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/06 07:57 upstream 01f95500a162 ae98e6b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/05 20:31 upstream 01f95500a162 6ca47dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/04 15:36 upstream e8ab83e34bdc b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/04 07:02 upstream 2a239ffbebb5 b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/03 10:54 upstream 95d3481af6dc b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/03 03:09 upstream 2bfcee565c3a b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/05/01 17:14 upstream 4f79eaa2ceac 51b137cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/30 10:39 upstream ca91b9500108 85a5a23f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/28 21:21 upstream f15d97df5afa aeb6ec69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/27 12:43 upstream 5bc1018675ec c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/25 19:34 upstream 02ddfb981de8 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/24 03:29 upstream a79be02bba5c 73a168d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/21 13:22 upstream 9d7a0577c9db 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/14 13:17 upstream 8ffd015db85f 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/12 07:17 upstream e618ee89561b 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/10 17:00 upstream 2eb959eeecc6 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/08 18:24 upstream 0af2f6be1b42 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/06 10:47 upstream f4d2ef48250a 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/05 17:49 upstream a8662bcd2ff1 c53ea9c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/05 07:07 upstream a52a3c18cdf3 c53ea9c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/04 10:40 upstream e48e99b6edf4 1c4febdb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/04 09:07 upstream e48e99b6edf4 d7ae3a11 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/04/03 02:34 upstream 92b71befc349 c799dfdd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/03/31 00:33 upstream aa918db707fb d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/03/29 10:35 upstream 7d06015d936c cf25e2c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/03/27 22:41 upstream 1a9239bb4253 6c09fb82 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/03/25 04:52 upstream 3ba7dfb8da62 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/02/25 07:34 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2025/01/04 00:51 upstream 63676eefb7a0 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
* Struck through repros no longer work on HEAD.