syzbot


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

Status: auto-closed as invalid on 2021/03/06 20:57
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 587d, last: 562d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / lookup_fast (5) 12 442d 514d 0/23 auto-closed as invalid on 2021/07/05 09:49
upstream KCSAN: data-race in __dentry_kill / lookup_fast (2) 5 723d 783d 0/23 auto-closed as invalid on 2020/09/27 09:27
upstream KCSAN: data-race in __dentry_kill / lookup_fast 10 805d 899d 0/23 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in __dentry_kill / lookup_fast (6) 1 269d 269d 0/23 auto-closed as invalid on 2021/12/25 02:52
upstream KCSAN: data-race in __dentry_kill / lookup_fast (3) 3 625d 617d 0/23 auto-closed as invalid on 2021/01/03 16:37

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

write to 0xffff88810d5d8a80 of 4 bytes by task 17137 on cpu 1:
 dentry_unlist fs/dcache.c:519 [inline]
 __dentry_kill+0x147/0x450 fs/dcache.c:575
 dentry_kill fs/dcache.c:692 [inline]
 dput+0x208/0x420 fs/dcache.c:885
 do_renameat2+0x5cf/0x900 fs/namei.c:4461
 __do_sys_rename fs/namei.c:4508 [inline]
 __se_sys_rename fs/namei.c:4506 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4506
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810d5d8a80 of 4 bytes by task 4878 on cpu 0:
 d_revalidate fs/namei.c:767 [inline]
 lookup_fast+0x15f/0x370 fs/namei.c:1493
 open_last_lookups fs/namei.c:3146 [inline]
 path_openat+0x45e/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: 0 PID: 4878 Comm: systemd-journal Not tainted 5.11.0-rc5-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 2021/01/30 20:53 upstream 0e9bcda5d286 fc9fd31e .config log report info KCSAN: data-race in __dentry_kill / lookup_fast
ci2-upstream-kcsan-gce 2021/01/23 05:44 upstream 83d09ad4b950 52e37319 .config log report info KCSAN: data-race in __dentry_kill / lookup_fast
ci2-upstream-kcsan-gce 2021/01/05 20:18 upstream 36bbbd0e234d a0234d98 .config log report info