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KCSAN: data-race in __fput / ep_remove

Status: auto-closed as invalid on 2021/06/02 19:47
Subsystems: fs
[Documentation on labels]
First crash: 1086d, last: 1086d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __fput / ep_remove (2) fs 2 699d 727d 0/26 auto-closed as invalid on 2022/06/25 02:37
upstream KCSAN: data-race in __fput / ep_remove (3) fs 1 435d 435d 0/26 auto-obsoleted due to no activity on 2023/04/06 07:53

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __fput / ep_remove

write to 0xffff8881009568d0 of 8 bytes by task 12727 on cpu 1:
 ep_remove+0x30b/0x360 fs/eventpoll.c:691
 ep_free+0x17b/0x200 fs/eventpoll.c:765
 ep_eventpoll_release+0x2e/0x40 fs/eventpoll.c:782
 __fput+0x25b/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 kernel/task_work.c:140
 get_signal+0x154d/0x15d0 kernel/signal.c:2554
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881009568d0 of 8 bytes by task 12746 on cpu 0:
 eventpoll_release include/linux/eventpoll.h:45 [inline]
 __fput+0x1de/0x4e0 fs/file_table.c:271
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 kernel/task_work.c:140
 get_signal+0x154d/0x15d0 kernel/signal.c:2554
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12746 Comm: syz-executor.2 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/04/28 19:41 upstream e359bce39d90 77e2b668 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __fput / ep_remove
* Struck through repros no longer work on HEAD.