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KCSAN: data-race in free_pid / zap_pid_ns_processes (5)

Status: auto-obsoleted due to no activity on 2024/05/15 08:15
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+335b9cda8abe9f28e1a4@syzkaller.appspotmail.com
First crash: 38d, last: 38d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] KCSAN: data-race in free_pid / zap_pid_ns_processes (5) 0 (1) 2024/04/10 08:30
Similar bugs (4)
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 1202d 1216d 0/26 auto-closed as invalid on 2021/03/08 05:19
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (4) kernel 2 1069d 1082d 0/26 auto-closed as invalid on 2021/07/19 14:02
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes (3) kernel 2 1129d 1145d 0/26 auto-closed as invalid on 2021/05/20 16:55
upstream KCSAN: data-race in free_pid / zap_pid_ns_processes kernel 12 1561d 1666d 0/26 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 0xffff88811257b5c8 of 4 bytes by task 10493 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:133 [inline]
 __exit_signal kernel/exit.c:202 [inline]
 release_task+0x6e7/0xc30 kernel/exit.c:259
 exit_notify kernel/exit.c:774 [inline]
 do_exit+0xf7d/0x1740 kernel/exit.c:898
 do_group_exit+0x102/0x150 kernel/exit.c:1027
 get_signal+0xf2f/0x1080 kernel/signal.c:2911
 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+0xe2/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff88811257b5c8 of 4 bytes by task 10223 on cpu 0:
 zap_pid_ns_processes+0x1ec/0x2c0 kernel/pid_namespace.c:249
 find_child_reaper kernel/exit.c:610 [inline]
 forget_original_parent kernel/exit.c:699 [inline]
 exit_notify kernel/exit.c:736 [inline]
 do_exit+0x14b4/0x1740 kernel/exit.c:898
 do_group_exit+0x102/0x150 kernel/exit.c:1027
 get_signal+0xf2f/0x1080 kernel/signal.c:2911
 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+0xe2/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

value changed: 0x00000002 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10223 Comm: syz-executor.4 Tainted: G        W          6.9.0-rc3-syzkaller-00011-g20cb38a7af88 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/10 08:15 upstream 20cb38a7af88 171ec371 .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.