syzbot


KCSAN: data-race in free_pid / zap_pid_ns_processes (6)

Status: moderation: reported on 2024/06/25 04:20
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+3ce72d4671ed12606441@syzkaller.appspotmail.com
First crash: 29d, last: 5d11h
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (2) kernel 2 1269d 1283d 0/27 auto-closed as invalid on 2021/03/08 05:19
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (4) kernel 2 1136d 1149d 0/27 auto-closed as invalid on 2021/07/19 14:02
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (5) kernel 1 105d 105d 0/27 auto-obsoleted due to no activity on 2024/05/15 08:15
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (3) kernel 2 1196d 1212d 0/27 auto-closed as invalid on 2021/05/20 16:55
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes kernel 12 1628d 1733d 0/27 auto-closed as invalid on 2020/04/18 12:14

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

read-write to 0xffff88810d5fd148 of 4 bytes by task 3434 on cpu 1:
 free_pid+0x80/0x170 kernel/pid.c:143
 __change_pid+0x19a/0x1c0 kernel/pid.c:367
 detach_pid+0x1c/0x30 kernel/pid.c:372
 __unhash_process kernel/exit.c:132 [inline]
 __exit_signal kernel/exit.c:201 [inline]
 release_task+0x6e7/0xc10 kernel/exit.c:258
 exit_notify kernel/exit.c:771 [inline]
 do_exit+0xf62/0x1720 kernel/exit.c:897
 do_group_exit+0x102/0x150 kernel/exit.c:1026
 get_signal+0xf2f/0x1080 kernel/signal.c:2917
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810d5fd148 of 4 bytes by task 3097 on cpu 0:
 zap_pid_ns_processes+0x1f2/0x2c0 kernel/pid_namespace.c:250
 find_child_reaper kernel/exit.c:607 [inline]
 forget_original_parent kernel/exit.c:696 [inline]
 exit_notify kernel/exit.c:733 [inline]
 do_exit+0x148c/0x1720 kernel/exit.c:897
 do_group_exit+0x102/0x150 kernel/exit.c:1026
 get_signal+0xf2f/0x1080 kernel/signal.c:2917
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000002 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3097 Comm: syz-executor Not tainted 6.10.0-syzkaller-08676-g720261cfc732 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/19 14:23 upstream 720261cfc732 ee4e11c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in free_pid / zap_pid_ns_processes
2024/07/13 20:01 upstream 528dd46d0fc3 eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in free_pid / zap_pid_ns_processes
2024/06/25 04:19 upstream 626737a5791b 215eef4a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in free_pid / zap_pid_ns_processes
* Struck through repros no longer work on HEAD.