syzbot


KCSAN: data-race in __d_lookup / __d_move

Status: auto-closed as invalid on 2022/01/08 02:29
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 357d, last: 357d

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

write to 0xffff888105871610 of 8 bytes by task 3948 on cpu 0:
 __hlist_bl_del include/linux/list_bl.h:128 [inline]
 ___d_drop fs/dcache.c:475 [inline]
 __d_move+0x453/0xeb0 fs/dcache.c:2902
 d_move+0x53/0x90 fs/dcache.c:2950
 vfs_rename+0xc75/0xe00 fs/namei.c:4641
 do_renameat2+0x6d7/0xa20 fs/namei.c:4777
 __do_sys_rename fs/namei.c:4823 [inline]
 __se_sys_rename fs/namei.c:4821 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4821
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888105871610 of 8 bytes by task 15280 on cpu 1:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:342 [inline]
 __d_lookup+0x14d/0x3b0 fs/dcache.c:2431
 lookup_fast+0x67/0x360 fs/namei.c:1615
 walk_component+0x6d/0x360 fs/namei.c:1966
 link_path_walk+0x56b/0x930
 path_openat+0x1a7/0x1eb0 fs/namei.c:3555
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_openat fs/open.c:1244 [inline]
 __se_sys_openat fs/open.c:1239 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1239
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff88814b242008 -> 0xffff88814b2449c8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15280 Comm: udevd Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/12/04 02:21 upstream 12119cfa1052 a617004c .config log report info KCSAN: data-race in __d_lookup / __d_move
* Struck through repros no longer work on HEAD.