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KCSAN: data-race in ___d_drop / __d_lookup (2)

Status: auto-obsoleted due to no activity on 2024/02/27 04:23
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+7bce4449dce3b3afdb37@syzkaller.appspotmail.com
First crash: 117d, last: 85d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ___d_drop / __d_lookup fs 1 276d 276d 0/26 auto-obsoleted due to no activity on 2023/08/20 05:59

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ___d_drop / __d_lookup

write to 0xffff8881056fe190 of 8 bytes by task 3078 on cpu 1:
 __hlist_bl_del include/linux/list_bl.h:128 [inline]
 ___d_drop+0x106/0x220 fs/dcache.c:501
 __d_drop fs/dcache.c:508 [inline]
 __dentry_kill+0x12d/0x4a0 fs/dcache.c:601
 shrink_kill fs/dcache.c:1048 [inline]
 shrink_dentry_list+0x1bc/0x3d0 fs/dcache.c:1075
 shrink_dcache_parent+0x43/0x1b0
 vfs_rmdir+0x283/0x2f0 fs/namei.c:4209
 do_rmdir+0x194/0x320 fs/namei.c:4264
 __do_sys_unlinkat fs/namei.c:4440 [inline]
 __se_sys_unlinkat fs/namei.c:4434 [inline]
 __x64_sys_unlinkat+0xa4/0xb0 fs/namei.c:4434
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881056fe190 of 8 bytes by task 2763 on cpu 0:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:341 [inline]
 __d_lookup+0x10e/0x380 fs/dcache.c:2315
 lookup_fast+0x4c/0x290 fs/namei.c:1651
 walk_component fs/namei.c:1997 [inline]
 link_path_walk+0x3f4/0x7e0 fs/namei.c:2328
 path_openat+0x1a0/0x1d30 fs/namei.c:3794
 do_filp_open+0xf6/0x200 fs/namei.c:3825
 do_sys_openat2+0xab/0x110 fs/open.c:1404
 do_sys_open fs/open.c:1419 [inline]
 __do_sys_openat fs/open.c:1435 [inline]
 __se_sys_openat fs/open.c:1430 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1430
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xffff888127de7d88 -> 0xffff8882374791f0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2763 Comm: udevd Not tainted 6.8.0-rc1-syzkaller-00024-g5d9248eed480 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/23 04:22 upstream 5d9248eed480 1c0ecc51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ___d_drop / __d_lookup
2023/12/21 19:48 upstream a4aebe936554 4f9530a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ___d_drop / __d_lookup
* Struck through repros no longer work on HEAD.