syzbot


KCSAN: data-race in __d_lookup_done / __dentry_kill (4)

Status: auto-closed as invalid on 2021/03/09 07:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 587d, last: 563d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (5) 5 442d 478d 0/23 auto-closed as invalid on 2021/07/08 04:16
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (3) 1 684d 684d 0/23 auto-closed as invalid on 2020/11/08 00:33
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (6) 1 117d 117d 0/23 auto-closed as invalid on 2022/05/29 05:25
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (2) 4 766d 786d 0/23 auto-closed as invalid on 2020/08/18 04:12
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill 29 853d 1026d 0/23 auto-closed as invalid on 2020/06/18 14:14

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

write to 0xffff88800cfea9c0 of 4 bytes by task 2041 on cpu 0:
 __d_lookup_done+0x8c/0x240 fs/dcache.c:2655
 __d_add+0x31e/0x450 fs/dcache.c:2675
 d_add+0x41/0x50 fs/dcache.c:2708
 simple_lookup+0x85/0x90 fs/libfs.c:74
 lookup_open fs/namei.c:3085 [inline]
 open_last_lookups fs/namei.c:3180 [inline]
 path_openat+0xa72/0x20a0 fs/namei.c:3368
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88800cfea9c0 of 4 bytes by task 2051 on cpu 1:
 dentry_unlist fs/dcache.c:544 [inline]
 __dentry_kill+0x1ef/0x450 fs/dcache.c:575
 dentry_kill fs/dcache.c:692 [inline]
 dput+0x208/0x420 fs/dcache.c:885
 handle_mounts fs/namei.c:1389 [inline]
 step_into+0x444/0xeb0 fs/namei.c:1691
 open_last_lookups fs/namei.c:3203 [inline]
 path_openat+0xfb9/0x20a0 fs/namei.c:3368
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2051 Comm: systemd-udevd Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/02/02 07:40 upstream 88bb507a74ea e6b95f32 .config log report info KCSAN: data-race in __d_lookup_done / __dentry_kill
ci2-upstream-kcsan-gce 2021/01/20 22:46 upstream 75439bc439e0 d4f4eca5 .config log report info KCSAN: data-race in __d_lookup_done / __dentry_kill
ci2-upstream-kcsan-gce 2021/01/08 22:21 upstream 6279d812eab6 c104d4a3 .config log report info