syzbot


KCSAN: data-race in free_pid / zap_pid_ns_processes
Status: auto-closed as invalid on 2020/04/18 12:14
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 943d, last: 838d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (2) 2 479d 493d 0/22 auto-closed as invalid on 2021/03/08 05:19
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (4) 2 346d 359d 0/22 auto-closed as invalid on 2021/07/19 14:02
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (3) 2 406d 422d 0/22 auto-closed as invalid on 2021/05/20 16:55

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

write to 0xffff888120d4c510 of 4 bytes by task 5231 on cpu 0:
 free_pid+0xfd/0x1c0 kernel/pid.c:134
 __change_pid+0x17c/0x1f0 kernel/pid.c:347
 detach_pid+0x29/0x40 kernel/pid.c:352
 __unhash_process kernel/exit.c:77 [inline]
 __exit_signal kernel/exit.c:157 [inline]
 release_task+0x9ec/0xc60 kernel/exit.c:207
 exit_notify kernel/exit.c:687 [inline]
 do_exit+0xd94/0x18c0 kernel/exit.c:818
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888120d4c510 of 4 bytes by task 1622 on cpu 1:
 zap_pid_ns_processes+0x212/0x310 kernel/pid_namespace.c:251
 find_child_reaper kernel/exit.c:530 [inline]
 forget_original_parent kernel/exit.c:619 [inline]
 exit_notify kernel/exit.c:656 [inline]
 do_exit+0x16bd/0x18c0 kernel/exit.c:818
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:904
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1622 Comm: syz-executor.2 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (12):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/02/08 12:05 https://github.com/google/ktsan.git kcsan f60f0f543333 06150bf1 .config log report
ci2-upstream-kcsan-gce 2020/02/01 13:13 https://github.com/google/ktsan.git kcsan 245a43005292 326d4c78 .config log report
ci2-upstream-kcsan-gce 2020/01/17 23:10 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config log report
ci2-upstream-kcsan-gce 2020/01/15 13:10 https://github.com/google/ktsan.git kcsan 245a43005292 fa12bd3c .config log report
ci2-upstream-kcsan-gce 2019/12/23 15:32 https://github.com/google/ktsan.git kcsan 245a43005292 be5c2c81 .config log report
ci2-upstream-kcsan-gce 2019/12/16 23:37 https://github.com/google/ktsan.git kcsan 245a43005292 0ae38e44 .config log report
ci2-upstream-kcsan-gce 2019/12/10 03:15 https://github.com/google/ktsan.git kcsan ef798c30ba4e b31eda3d .config log report
ci2-upstream-kcsan-gce 2019/12/04 19:47 https://github.com/google/ktsan.git kcsan ef798c30ba4e b2088328 .config log report
ci2-upstream-kcsan-gce 2019/12/01 08:33 https://github.com/google/ktsan.git kcsan ef798c30ba4e a76bf83f .config log report
ci2-upstream-kcsan-gce 2019/11/12 13:05 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config log report
ci2-upstream-kcsan-gce 2019/11/10 01:49 https://github.com/google/ktsan.git kcsan 94c006602e13 dc438b91 .config log report
ci2-upstream-kcsan-gce 2019/10/26 05:54 https://github.com/google/ktsan.git kcsan 05f2236801fe 413926c5 .config log report