syzbot


KCSAN: data-race in memcpy_and_pad / release_task

Status: moderation: reported on 2025/06/07 05:38
Subsystems: modules
[Documentation on labels]
Reported-by: syzbot+d06247460da822ececd6@syzkaller.appspotmail.com
First crash: 237d, last: 1d11h

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

write to 0xffff8881001d9638 of 8 bytes by task 12315 on cpu 0:
 __list_del include/linux/list.h:203 [inline]
 __list_del_entry include/linux/list.h:226 [inline]
 list_del_init include/linux/list.h:295 [inline]
 __unhash_process kernel/exit.c:150 [inline]
 __exit_signal kernel/exit.c:212 [inline]
 release_task+0x76f/0xb60 kernel/exit.c:265
 exit_notify kernel/exit.c:777 [inline]
 do_exit+0xd56/0x1590 kernel/exit.c:983
 kthread_exit+0x93/0x190 kernel/kthread.c:336
 kthread+0xc6/0x510 kernel/kthread.c:429
 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read to 0xffff8881001d9080 of 3264 bytes by task 2 on cpu 1:
 memcpy_and_pad+0x48/0x80 lib/string_helpers.c:1007
 arch_dup_task_struct+0x2c/0x40 arch/x86/kernel/process.c:108
 dup_task_struct+0x6e/0x940 kernel/fork.c:919
 copy_process+0x37e/0x1f10 kernel/fork.c:2052
 kernel_clone+0x16b/0x5b0 kernel/fork.c:2651
 kernel_thread+0xe5/0x120 kernel/fork.c:2712
 create_kthread kernel/kthread.c:486 [inline]
 kthreadd+0x26b/0x330 kernel/kthread.c:844
 ret_from_fork+0x148/0x280 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: 2 Comm: kthreadd Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================

Crashes (146):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/29 15:46 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/29 04:04 upstream 8dfce8991b95 0adc945e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/28 08:49 upstream 1f97d9dcf536 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/21 15:04 upstream 6c790212c588 6f1aa2f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/20 18:29 upstream 24d479d26b25 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/17 13:09 upstream d3eeb99bbc99 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/16 17:05 upstream 983d014aafb1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/15 00:04 upstream e0d4140e8043 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/14 12:06 upstream c537e12daeec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/10 23:28 upstream 97313d6113ab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/09 23:38 upstream 372800cb95a3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/06 23:15 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/06 15:30 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/05 13:43 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/02 22:57 upstream 9b0436804460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2026/01/01 10:50 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/31 13:44 upstream c8ebd433459b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/30 18:02 upstream dbf8fe85a16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/30 16:09 upstream 8640b74557fc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/29 00:17 upstream c875a6c32467 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/28 07:03 upstream d26143bb38e2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/22 06:26 upstream 765b233a9b94 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/20 04:53 upstream dd9b004b7ff3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/16 05:02 upstream 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/11 00:48 upstream 0048fbb4011e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/08 18:52 upstream c2f2b01b74be d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/07 05:09 upstream cc3ee4ba57b7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/06 18:11 upstream 416f99c3b16f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/03 09:10 upstream d61f1cc5db79 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/12/02 00:25 upstream 1d18101a644e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/27 15:49 upstream 765e56e41a5a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/27 01:53 upstream 4941a17751c9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/24 21:43 upstream ac3fd01e4c1e bf6fe8fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/24 11:16 upstream d0e88704d96c 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/22 19:20 upstream 89edd36fd801 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/22 01:42 upstream 2eba5e05d9bc 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/20 03:51 upstream 23cb64fb7625 26ee5237 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/19 15:11 upstream 8b690556d8fe 26ee5237 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/18 03:55 upstream e7c375b18160 ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/16 05:59 upstream f824272b6e3f f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/13 20:32 upstream 2ccec5944606 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/12 18:32 upstream 24172e0d7990 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/11 13:20 upstream 4427259cc7f7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/10 07:53 upstream e9a6fb0bcdd7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/08 23:59 upstream 7bb4d6512545 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/07 11:53 upstream 4a0c9b339199 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/06 03:57 upstream 1c353dc8d962 a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/11/03 04:14 upstream 6146a0f1dfae 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
2025/06/07 05:38 upstream c0c9379f235d 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in memcpy_and_pad / release_task
* Struck through repros no longer work on HEAD.