syzbot


KCSAN: data-race in copy_process / free_pid (13)

Status: moderation: reported on 2024/09/13 19:15
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+791d57f412d4c727a49b@syzkaller.appspotmail.com
First crash: 4d18h, last: 8h01m
Similar bugs (12)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in copy_process / free_pid (8) kernel 1 649d 649d 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 115d 115d 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 1741d 1741d 0/28 auto-closed as invalid on 2020/02/20 19:37
upstream KCSAN: data-race in copy_process / free_pid (10) kernel 23 154d 283d 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 398d 484d 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 840d 843d 0/28 auto-closed as invalid on 2022/07/06 07:38
upstream KCSAN: data-race in copy_process / free_pid (4) kernel 1 1145d 1145d 0/28 auto-closed as invalid on 2021/09/04 11:26
upstream KCSAN: data-race in copy_process / free_pid (5) kernel 32 980d 1099d 0/28 auto-closed as invalid on 2022/02/15 18:33
upstream KCSAN: data-race in copy_process / free_pid (2) kasan 1 1656d 1656d 0/28 auto-closed as invalid on 2020/05/15 22:36
upstream KCSAN: data-race in copy_process / free_pid (7) kernel 4 739d 792d 0/28 auto-obsoleted due to no activity on 2022/10/14 18:22
upstream KCSAN: data-race in copy_process / free_pid (3) kernel 1 1335d 1335d 0/28 auto-closed as invalid on 2021/02/26 04:07
upstream KCSAN: data-race in copy_process / free_pid (12) kernel 1 73d 73d 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 0xffffffff8665d918 of 4 bytes by task 15616 on cpu 0:
 free_pid+0x80/0x170 kernel/pid.c:143
 copy_process+0x19d0/0x1f90 kernel/fork.c:2621
 kernel_clone+0x167/0x5e0 kernel/fork.c:2781
 __do_sys_clone3 kernel/fork.c:3085 [inline]
 __se_sys_clone3+0x1b5/0x1f0 kernel/fork.c:3064
 __x64_sys_clone3+0x31/0x40 kernel/fork.c:3064
 x64_sys_call+0x287d/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:436
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff8665d918 of 4 bytes by task 11165 on cpu 1:
 copy_process+0x15e3/0x1f90 kernel/fork.c:2527
 kernel_clone+0x167/0x5e0 kernel/fork.c:2781
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2859
 call_usermodehelper_exec_work+0x41/0x150 kernel/umh.c:172
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3393
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x8000022e -> 0x8000022d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11165 Comm: kworker/u8:13 Tainted: G        W          6.11.0-syzkaller-04557-g2f27fce67173 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: events_unbound call_usermodehelper_exec_work
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/18 05:28 upstream 2f27fce67173 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2024/09/16 19:25 upstream adfc3ded5c33 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in copy_process / free_pid
2024/09/13 19:15 upstream 196145c606d0 b58f933c .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.