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KCSAN: data-race in __dentry_kill / d_set_d_op (20)

Status: moderation: reported on 2025/04/09 04:25
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+b5cb423e9d7e50e94e92@syzkaller.appspotmail.com
First crash: 17d, last: 17d
▶ ▼ Similar bugs (19)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (9) fs 1 1176d 1176d 0/28 auto-closed as invalid on 2022/03/12 00:21
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (17) fs 1 373d 373d 0/28 auto-obsoleted due to no activity on 2024/05/23 05:15
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (7) fs 2 1411d 1445d 0/28 auto-closed as invalid on 2021/07/19 11:09
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (3) fs 6 1783d 1824d 0/28 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (2) fs 9 1913d 1982d 0/28 auto-closed as invalid on 2020/04/08 20:57
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (5) fs 1 1632d 1600d 0/28 auto-closed as invalid on 2020/12/21 11:58
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (10) fs 5 1075d 1137d 0/28 auto-closed as invalid on 2022/06/20 15:46
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (15) fs 13 584d 644d 0/28 auto-obsoleted due to no activity on 2023/10/24 14:04
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (14) fs 1 680d 680d 0/28 auto-obsoleted due to no activity on 2023/07/21 00:16
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (4) fs 3 1713d 1732d 0/28 auto-closed as invalid on 2020/09/21 06:01
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (11) fs 1 1035d 1035d 0/28 auto-closed as invalid on 2022/07/30 10:14
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (6) fs 1 1503d 1503d 0/28 auto-closed as invalid on 2021/04/18 21:16
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (16) fs 6 482d 503d 0/28 auto-obsoleted due to no activity on 2024/02/04 06:56
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (12) fs 3 940d 986d 0/28 auto-obsoleted due to no activity on 2022/11/02 16:09
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (8) fs 13 1215d 1372d 0/28 auto-closed as invalid on 2022/02/01 06:29
upstream KCSAN: data-race in __dentry_kill / d_set_d_op fs 3 1993d 2000d 0/28 closed as invalid on 2019/11/19 14:14
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (18) fs 4 260d 303d 0/28 auto-obsoleted due to no activity on 2024/09/13 03:18
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (13) fs 4 791d 850d 0/28 auto-obsoleted due to no activity on 2023/04/04 19:35
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (19) fs 1 140d 140d 0/28 auto-obsoleted due to no activity on 2025/02/01 04:42

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __dentry_kill / d_set_d_op

read-write to 0xffff88811726a6c0 of 4 bytes by task 9761 on cpu 0:
 d_set_d_op+0x15b/0x1f0 fs/dcache.c:1852
 simple_lookup+0x7c/0xa0 fs/libfs.c:79
 lookup_open fs/namei.c:3644 [inline]
 open_last_lookups fs/namei.c:3765 [inline]
 path_openat+0xd76/0x2000 fs/namei.c:4001
 do_filp_open+0x115/0x240 fs/namei.c:4031
 do_sys_openat2+0xaa/0x110 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0xf8/0x120 fs/open.c:1455
 x64_sys_call+0x1ac/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811726a6c0 of 4 bytes by task 9764 on cpu 1:
 dentry_unlist fs/dcache.c:630 [inline]
 __dentry_kill+0x2af/0x4c0 fs/dcache.c:674
 dput+0x5c/0xd0 fs/dcache.c:902
 handle_mounts fs/namei.c:1640 [inline]
 step_into+0x226/0x860 fs/namei.c:1966
 open_last_lookups fs/namei.c:3792 [inline]
 path_openat+0x141f/0x2000 fs/namei.c:4001
 do_filp_open+0x115/0x240 fs/namei.c:4031
 do_sys_openat2+0xaa/0x110 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0xf8/0x120 fs/open.c:1455
 x64_sys_call+0x1ac/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x01000000 -> 0x00000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 9764 Comm: syz.0.13610 Tainted: G        W           6.15.0-rc1-syzkaller-00025-gbec7dcbc242c #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/09 04:24 upstream bec7dcbc242c a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_set_d_op
* Struck through repros no longer work on HEAD.