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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: 86d, last: 11d
▶ ▼ 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 1245d 1245d 0/29 auto-closed as invalid on 2022/03/12 00:21
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (17) fs 1 442d 442d 0/29 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 1481d 1514d 0/29 auto-closed as invalid on 2021/07/19 11:09
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (3) fs 6 1853d 1893d 0/29 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (2) fs 9 1982d 2051d 0/29 auto-closed as invalid on 2020/04/08 20:57
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (5) fs 1 1701d 1670d 0/29 auto-closed as invalid on 2020/12/21 11:58
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (10) fs 5 1144d 1206d 0/29 auto-closed as invalid on 2022/06/20 15:46
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (15) fs 13 653d 713d 0/29 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 749d 749d 0/29 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 1782d 1801d 0/29 auto-closed as invalid on 2020/09/21 06:01
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (11) fs 1 1105d 1105d 0/29 auto-closed as invalid on 2022/07/30 10:14
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (6) fs 1 1572d 1572d 0/29 auto-closed as invalid on 2021/04/18 21:16
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (16) fs 6 551d 572d 0/29 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 1009d 1055d 0/29 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 1284d 1441d 0/29 auto-closed as invalid on 2022/02/01 06:29
upstream KCSAN: data-race in __dentry_kill / d_set_d_op fs 3 2063d 2070d 0/29 closed as invalid on 2019/11/19 14:14
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (18) fs 4 329d 372d 0/29 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 860d 919d 0/29 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 209d 209d 0/29 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 0xffff888106a283c0 of 4 bytes by task 11173 on cpu 1:
 d_set_d_op+0x143/0x1d0 fs/dcache.c:1861
 simple_lookup+0x7c/0xa0 fs/libfs.c:79
 lookup_open fs/namei.c:3695 [inline]
 open_last_lookups fs/namei.c:3816 [inline]
 path_openat+0xcf3/0x2170 fs/namei.c:4052
 do_filp_open+0x109/0x230 fs/namei.c:4082
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x1af/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888106a283c0 of 4 bytes by task 11926 on cpu 0:
 dentry_unlist fs/dcache.c:639 [inline]
 __dentry_kill+0x2aa/0x4b0 fs/dcache.c:683
 dput+0x5e/0xd0 fs/dcache.c:911
 handle_mounts fs/namei.c:1640 [inline]
 step_into+0x5b2/0x820 fs/namei.c:1976
 open_last_lookups fs/namei.c:3843 [inline]
 path_openat+0x13e8/0x2170 fs/namei.c:4052
 do_filp_open+0x109/0x230 fs/namei.c:4082
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x1af/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 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: 0 UID: 0 PID: 11926 Comm: syz-executor Tainted: G        W           6.16.0-rc2-syzkaller-00378-gb67ec639010f #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/23 00:28 upstream b67ec639010f d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_set_d_op
2025/05/23 19:26 upstream eccf6f2f6ab9 f8cc0c83 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_set_d_op
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.