KCSAN: data-race in __dentry_kill / lookup_fast (13)

Status: auto-obsoleted due to no activity on 2025/06/08 21:40
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+d39da0f4ddf3340ad108@syzkaller.appspotmail.com
First crash: 528d, last: 480d
▶ ▼ Similar bugs (14)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / lookup_fast (5) fs 6 12 1893d 1966d 0/29 auto-closed as invalid on 2021/07/05 09:49
upstream KCSAN: data-race in __dentry_kill / lookup_fast (8) fs 6 8 1205d 1268d 0/29 auto-obsoleted due to no activity on 2023/05/25 00:07
upstream KCSAN: data-race in __dentry_kill / lookup_fast (2) fs 6 5 2174d 2234d 0/29 auto-closed as invalid on 2020/09/27 09:27
upstream KCSAN: data-race in __dentry_kill / lookup_fast fs 6 10 2257d 2350d 0/29 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in __dentry_kill / lookup_fast (11) fs 6 1 748d 748d 0/29 auto-obsoleted due to no activity on 2024/08/23 20:28
upstream KCSAN: data-race in __dentry_kill / lookup_fast (10) fs 6 3 858d 896d 0/29 auto-obsoleted due to no activity on 2024/05/05 12:07
upstream KCSAN: data-race in __dentry_kill / lookup_fast (12) fs 6 3 584d 637d 0/29 auto-obsoleted due to no activity on 2025/02/24 08:27
upstream KCSAN: data-race in __dentry_kill / lookup_fast (14) fs 6 1 348d 348d 0/29 auto-obsoleted due to no activity on 2025/10/18 05:13
upstream KCSAN: data-race in __dentry_kill / lookup_fast (7) fs 6 27 1315d 1575d 0/29 auto-obsoleted due to no activity on 2023/02/12 11:35
upstream KCSAN: data-race in __dentry_kill / lookup_fast (15) race:benign prio:low fs 6 15 57d 193d 0/29 auto-obsoleted due to no activity on 2026/08/05 23:19
upstream KCSAN: data-race in __dentry_kill / lookup_fast (6) fs 6 1 1720d 1720d 0/29 auto-closed as invalid on 2021/12/25 02:52
upstream KCSAN: data-race in __dentry_kill / lookup_fast (4) fs 6 3 2014d 2039d 0/29 auto-closed as invalid on 2021/03/06 20:57
upstream KCSAN: data-race in __dentry_kill / lookup_fast (3) fs 6 3 2076d 2068d 0/29 auto-closed as invalid on 2021/01/03 16:37
upstream KCSAN: data-race in __dentry_kill / lookup_fast (9) fs 6 31 936d 972d 0/29 auto-obsoleted due to no activity on 2024/02/17 10:11

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

read-write to 0xffff8881056fb900 of 4 bytes by task 3315 on cpu 0:
 dentry_unlist fs/dcache.c:605 [inline]
 __dentry_kill+0x22e/0x4c0 fs/dcache.c:674
 dput+0x5c/0xd0 fs/dcache.c:902
 __fput+0x428/0x640 fs/file_table.c:473
 fput_close_sync+0xc0/0x110 fs/file_table.c:570
 __do_sys_close fs/open.c:1581 [inline]
 __se_sys_close fs/open.c:1566 [inline]
 __x64_sys_close+0x55/0xe0 fs/open.c:1566
 x64_sys_call+0x262b/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:4
 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 0xffff8881056fb900 of 4 bytes by task 3304 on cpu 1:
 d_revalidate fs/namei.c:928 [inline]
 lookup_fast+0xf0/0x310 fs/namei.c:1755
 lookup_fast_for_open fs/namei.c:3703 [inline]
 open_last_lookups fs/namei.c:3736 [inline]
 path_openat+0x431/0x2000 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: 0x00200008 -> 0x00004008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3304 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller-00333-g5aaaedb0cb54 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
==================================================================
BUG: KCSAN: data-race in __dentry_kill / step_into

read-write to 0xffff888110ec3a80 of 4 bytes by task 3315 on cpu 0:
 dentry_unlist fs/dcache.c:605 [inline]
 __dentry_kill+0x22e/0x4c0 fs/dcache.c:674
 dput+0x5c/0xd0 fs/dcache.c:902
 __fput+0x428/0x640 fs/file_table.c:473
 fput_close_sync+0xc0/0x110 fs/file_table.c:570
 __do_sys_close fs/open.c:1581 [inline]
 __se_sys_close fs/open.c:1566 [inline]
 __x64_sys_close+0x55/0xe0 fs/open.c:1566
 x64_sys_call+0x262b/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:4
 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 0xffff888110ec3a80 of 4 bytes by task 3304 on cpu 1:
 __d_entry_type include/linux/dcache.h:415 [inline]
 d_is_symlink include/linux/dcache.h:445 [inline]
 step_into+0x128/0x860 fs/namei.c:1971
 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: 0x00200008 -> 0x00004008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3304 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller-00333-g5aaaedb0cb54 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
==================================================================
BUG: KCSAN: data-race in __dentry_kill / fast_dput

write to 0xffff8881063ce250 of 8 bytes by task 3315 on cpu 1:
 __d_drop fs/dcache.c:566 [inline]
 __dentry_kill+0x13e/0x4c0 fs/dcache.c:658
 dput+0x5c/0xd0 fs/dcache.c:902
 __fput+0x428/0x640 fs/file_table.c:473
 fput_close_sync+0xc0/0x110 fs/file_table.c:570
 __do_sys_close fs/open.c:1581 [inline]
 __se_sys_close fs/open.c:1566 [inline]
 __x64_sys_close+0x55/0xe0 fs/open.c:1566
 x64_sys_call+0x262b/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:4
 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 0xffff8881063ce250 of 8 bytes by task 3304 on cpu 0:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:365 [inline]
 retain_dentry fs/dcache.c:743 [inline]
 fast_dput+0x65/0x2c0 fs/dcache.c:839
 dput+0x24/0xd0 fs/dcache.c:896
 do_unlinkat+0x226/0x4b0 fs/namei.c:4611
 __do_sys_unlink fs/namei.c:4654 [inline]
 __se_sys_unlink fs/namei.c:4652 [inline]
 __x64_sys_unlink+0x2e/0x40 fs/namei.c:4652
 x64_sys_call+0x2358/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:88
 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: 0xffff888237581438 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3304 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller-00333-g5aaaedb0cb54 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/13 21:39 upstream 5aaaedb0cb54 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2025/03/16 01:54 upstream 3571e8b091f4 e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2025/03/02 09:40 upstream ece144f151ac c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2025/03/02 09:40 upstream ece144f151ac c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2025/02/24 20:41 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
* Struck through repros no longer work on HEAD.