KCSAN: data-race in __dentry_kill / __dentry

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __dentry_kill / __dentry_kill (2) fs				1	90d	90d	0/27	auto-obsoleted due to no activity on 2024/07/18 14:41
upstream	KCSAN: data-race in __dentry_kill / __dentry_kill fs				1	155d	155d	0/27	auto-obsoleted due to no activity on 2024/05/15 11:32

==================================================================
BUG: KCSAN: data-race in __dentry_kill / __dentry_kill

write to 0xffff8881069ccb40 of 4 bytes by task 7223 on cpu 1:
 d_lru_del fs/dcache.c:444 [inline]
 __dentry_kill+0xa3/0x4c0 fs/dcache.c:605
 dput+0x5c/0xd0 fs/dcache.c:852
 lookup_fast+0x25c/0x2a0 fs/namei.c:1684
 walk_component fs/namei.c:2035 [inline]
 link_path_walk+0x464/0x820 fs/namei.c:2404
 path_openat+0x1aa/0x1f10 fs/namei.c:3882
 do_filp_open+0xf7/0x200 fs/namei.c:3913
 do_sys_openat2+0xab/0x120 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1442
 x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258
 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 0xffff8881069ccb40 of 4 bytes by task 3534 on cpu 0:
 dentry_unlist fs/dcache.c:580 [inline]
 __dentry_kill+0x2af/0x4c0 fs/dcache.c:624
 dput+0x5c/0xd0 fs/dcache.c:852
 lookup_fast+0x25c/0x2a0 fs/namei.c:1684
 walk_component fs/namei.c:2035 [inline]
 link_path_walk+0x464/0x820 fs/namei.c:2404
 path_openat+0x1aa/0x1f10 fs/namei.c:3882
 do_filp_open+0xf7/0x200 fs/namei.c:3913
 do_sys_openat2+0xab/0x120 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1442
 x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0x00280004 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3534 Comm: udevd Not tainted 6.11.0-rc2-syzkaller-00257-g5189dafa4cf9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================
udevd[3534]: inotify_add_watch(7, /dev/loop2p1, 10) failed: No such file or directory
udevd[3534]: inotify_add_watch(7, /dev/loop2p1, 10) failed: No such file or directory
udevd[3534]: inotify_add_watch(7, /dev/loop2p1, 10) failed: No such file or directory