syzbot


KCSAN: data-race in alloc_pid / copy_process (2)

Status: moderation: reported on 2020/06/09 14:58
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+0718f65353d72efaac1e@syzkaller.appspotmail.com
First crash: 2187d, last: 1d14h
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 (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in alloc_pid / copy_process kernel 6 5 2205d 2216d 0/29 closed as invalid on 2019/11/19 13:24

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

read-write to 0xffffffff8685ff98 of 4 bytes by task 12 on cpu 0:
 alloc_pid+0x539/0x720 kernel/pid.c:282
 copy_process+0xe25/0x2000 kernel/fork.c:2197
 kernel_clone+0x16c/0x5c0 kernel/fork.c:2609
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2685
 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:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff8685ff98 of 4 bytes by task 53 on cpu 1:
 copy_process+0x17fc/0x2000 kernel/fork.c:2354
 kernel_clone+0x16c/0x5c0 kernel/fork.c:2609
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2685
 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:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x800000c7 -> 0x800000c8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 53 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events_unbound call_usermodehelper_exec_work
==================================================================
netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0

Crashes (3279):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/14 20:25 upstream d4f8cccc6230 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/14 06:41 upstream 6da43bbeb691 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/13 17:01 upstream 2ccec5944606 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/13 04:54 upstream e927c520e1ba 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/12 19:37 upstream 24172e0d7990 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/11 23:35 upstream 24172e0d7990 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/11 07:59 upstream 4427259cc7f7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/11 00:30 upstream 4ea7c1717f3f 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/10 12:46 upstream e9a6fb0bcdd7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/09 16:51 upstream 439fc29dfd3b 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/09 01:03 upstream 7bb4d6512545 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/07 23:25 upstream da32d155f4a8 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/06 18:27 upstream c2c2ccfd4ba7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/05 12:20 upstream 17d85f33a83b a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/04 13:02 upstream c9cfc122f037 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/04 10:40 upstream 8bb886cb8f3a 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/03 01:27 upstream 6146a0f1dfae 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/11/01 22:00 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/31 03:46 upstream d127176862a9 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/29 17:54 upstream e53642b87a4f fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/28 23:32 upstream 8eefed8f65cc fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/28 11:02 upstream fd57572253bc fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/27 17:02 upstream dcb6fa37fd7b fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/27 04:58 upstream dbfc6422a34d c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/26 01:59 upstream 566771afc7a8 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/25 00:13 upstream d2818517e348 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/23 07:47 upstream 43e9ad0c55a3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/23 01:58 upstream dd72c8fcf6d3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/22 09:45 upstream 552c50713f27 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/21 22:00 upstream 6548d364a3e8 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/19 17:20 upstream d9043c79ba68 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/19 00:33 upstream 1c64efcb083c 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/18 14:35 upstream f406055cb18c 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/14 21:09 upstream 9b332cece987 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/13 05:55 upstream 3a8660878839 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/13 02:22 upstream 8765f467912f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/12 05:41 upstream 67029a49db6c ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/09 14:33 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/09 01:10 upstream cd5a0afbdf80 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/08 11:33 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/07 18:09 upstream 971199ad2a0f 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/07 02:33 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/06 14:52 upstream fd94619c4336 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/06 04:37 upstream 7a405dbb0f03 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/05 11:40 upstream 6093a688a07d 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/04 22:32 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/04 11:05 upstream cbf33b8e0b36 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/02 22:38 upstream 7f7072574127 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/10/02 09:40 upstream 080ffb4bec4d 267f56c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2025/09/30 00:33 upstream 1896ce8eb6c6 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2021/01/17 10:24 upstream 0da0a8a0a0e1 813be542 .config console log report info ci2-upstream-kcsan-gce
2020/06/08 23:26 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0d60b78a .config console log report ci2-upstream-kcsan-gce
2020/06/05 14:51 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 d36418e9 .config console log report ci2-upstream-kcsan-gce
2019/11/20 23:46 https://github.com/google/ktsan.git kcsan 5863cc791e4c 8098ea0f .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.