syzbot


KCSAN: data-race in fsnotify_event_needs_parent / fsnotify_put_mark

Status: moderation: reported on 2024/05/23 10:15
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+8e392ba0f2f77b424b3f@syzkaller.appspotmail.com
First crash: 22d, last: 12d

Sample crash report:
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in fsnotify_event_needs_parent / fsnotify_put_mark

write to 0xffff88810122dd44 of 4 bytes by task 3066 on cpu 0:
 fsnotify_detach_connector_from_object fs/notify/mark.c:304 [inline]
 fsnotify_put_mark+0x2d8/0x5d0 fs/notify/mark.c:367
 __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:819 [inline]
 __se_sys_inotify_rm_watch+0x105/0x180 fs/notify/inotify/inotify_user.c:793
 __x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:793
 x64_sys_call+0x1b06/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:256
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810122dd44 of 4 bytes by task 3104 on cpu 1:
 fsnotify_event_needs_parent+0x47/0x100 fs/notify/fsnotify.c:175
 __fsnotify_parent+0x178/0x370 fs/notify/fsnotify.c:222
 fsnotify_parent include/linux/fsnotify.h:96 [inline]
 fsnotify_file include/linux/fsnotify.h:125 [inline]
 fsnotify_close include/linux/fsnotify.h:406 [inline]
 __fput+0x1f7/0x660 fs/file_table.c:408
 __fput_sync+0x44/0x60 fs/file_table.c:507
 __do_sys_close fs/open.c:1555 [inline]
 __se_sys_close+0x101/0x1b0 fs/open.c:1540
 __x64_sys_close+0x1f/0x30 fs/open.c:1540
 x64_sys_call+0x25f1/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00002008 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3104 Comm: syz-executor.4 Not tainted 6.10.0-rc1-syzkaller-00296-g89be4025b0db #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/02 04:47 upstream 89be4025b0db 3113787f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_event_needs_parent / fsnotify_put_mark
2024/05/27 16:29 upstream 2bfcfd584ff5 761766e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_event_needs_parent / fsnotify_put_mark
2024/05/27 09:08 upstream 1613e604df0c a10a183e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_event_needs_parent / fsnotify_put_mark
2024/05/23 10:15 upstream 2a8120d7b482 4c2072ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_event_needs_parent / fsnotify_put_mark
* Struck through repros no longer work on HEAD.