syzbot


KCSAN: data-race in fsnotify / fsnotify_put_mark (2)

Status: moderation: reported on 2024/06/29 05:55
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+43f02eff7fe42b98048a@syzkaller.appspotmail.com
First crash: 3d05h, last: 1d10h
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in fsnotify / fsnotify_put_mark fs 832 768d 1419d 0/27 auto-closed as invalid on 2022/06/30 10:12

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

write to 0xffff8881001c9764 of 4 bytes by task 3071 on cpu 1:
 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 0xffff8881001c9764 of 4 bytes by task 3100 on cpu 0:
 fsnotify+0x36c/0x11a0 fs/notify/fsnotify.c:553
 __fsnotify_parent+0x285/0x370 fs/notify/fsnotify.c:250
 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: 0 PID: 3100 Comm: syz-executor Tainted: G        W          6.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/01 01:14 upstream 22a40d14b572 757f06b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify / fsnotify_put_mark
2024/06/29 05:55 upstream 6c0483dbfe72 757f06b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify / fsnotify_put_mark
* Struck through repros no longer work on HEAD.