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KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask (4)

Status: moderation: reported on 2024/03/20 10:08
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+783d283962125a29c140@syzkaller.appspotmail.com
First crash: 37d, last: 9d15h
▶ ▼ Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask fs 1 503d 503d 0/26 auto-obsoleted due to no activity on 2023/02/11 07:53
upstream KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask (3) fs 1 173d 138d 0/26 auto-obsoleted due to no activity on 2023/12/25 00:07
upstream KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask (2) fs 1 239d 239d 0/26 auto-obsoleted due to no activity on 2023/10/05 20:31

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask

write to 0xffff888101089764 of 4 bytes by task 3087 on cpu 1:
 __fsnotify_recalc_mask+0x204/0x300 fs/notify/mark.c:174
 fsnotify_recalc_mask fs/notify/mark.c:191 [inline]
 fsnotify_add_mark_locked+0x740/0x8c0 fs/notify/mark.c:695
 fsnotify_add_inode_mark_locked include/linux/fsnotify_backend.h:783 [inline]
 inotify_new_watch fs/notify/inotify/inotify_user.c:620 [inline]
 inotify_update_watch fs/notify/inotify/inotify_user.c:647 [inline]
 __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:786 [inline]
 __se_sys_inotify_add_watch+0x669/0x820 fs/notify/inotify/inotify_user.c:729
 __x64_sys_inotify_add_watch+0x43/0x50 fs/notify/inotify/inotify_user.c:729
 x64_sys_call+0x1aee/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:255
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888101089764 of 4 bytes by task 3108 on cpu 0:
 fsnotify_object_watched fs/notify/fsnotify.c:173 [inline]
 __fsnotify_parent+0xd4/0x370 fs/notify/fsnotify.c:203
 fsnotify_parent include/linux/fsnotify.h:83 [inline]
 fsnotify_file include/linux/fsnotify.h:106 [inline]
 fsnotify_close include/linux/fsnotify.h:387 [inline]
 __fput+0x1ff/0x660 fs/file_table.c:408
 __fput_sync+0x44/0x60 fs/file_table.c:507
 __do_sys_close fs/open.c:1556 [inline]
 __se_sys_close+0x101/0x1b0 fs/open.c:1541
 __x64_sys_close+0x1f/0x30 fs/open.c:1541
 x64_sys_call+0x25b9/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00002008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3108 Comm: syz-executor.1 Not tainted 6.9.0-rc4-syzkaller-00031-g96fca68c4fbf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================
EXT4-fs (loop1): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop1): unmounting filesystem 00000000-0000-0000-0000-000000000000.

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/17 16:38 upstream 96fca68c4fbf acc528cb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask
2024/03/20 10:07 upstream a4145ce1e7bc a485f239 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __fsnotify_parent / __fsnotify_recalc_mask
* Struck through repros no longer work on HEAD.