syzbot


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: 24d, last: 24d
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 490d 490d 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 160d 125d 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 226d 226d 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 0xffff8881012b5d44 of 4 bytes by task 3690 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
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

read to 0xffff8881012b5d44 of 4 bytes by task 8645 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_open include/linux/fsnotify.h:376 [inline]
 do_dentry_open+0xa61/0xbe0 fs/open.c:1011
 vfs_open+0x4a/0x60 fs/open.c:1089
 do_open fs/namei.c:3642 [inline]
 path_openat+0x18ba/0x1d80 fs/namei.c:3799
 do_filp_open+0xf7/0x200 fs/namei.c:3826
 do_sys_openat2+0xab/0x120 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1432
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

value changed: 0x00000000 -> 0x00002008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8645 Comm: syz-executor.3 Not tainted 6.8.0-syzkaller-11743-ga4145ce1e7bc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
==================================================================
loop3: detected capacity change from 0 to 512
EXT4-fs (loop3): ext4_check_descriptors: Checksum for group 0 failed (43602!=33349)
EXT4-fs (loop3): group descriptors corrupted!

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.