syzbot


KCSAN: data-race in __dentry_kill / lookup_fast

Status: closed as invalid on 2020/06/18 14:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1005d, last: 912d
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 548d 621d 0/24 auto-closed as invalid on 2021/07/05 09:49
upstream KCSAN: data-race in __dentry_kill / lookup_fast (2) 5 829d 889d 0/24 auto-closed as invalid on 2020/09/27 09:27
upstream KCSAN: data-race in __dentry_kill / lookup_fast (6) 1 376d 376d 0/24 auto-closed as invalid on 2021/12/25 02:52
upstream KCSAN: data-race in __dentry_kill / lookup_fast (4) 3 669d 694d 0/24 auto-closed as invalid on 2021/03/06 20:57
upstream KCSAN: data-race in __dentry_kill / lookup_fast (3) 3 731d 723d 0/24 auto-closed as invalid on 2021/01/03 16:37

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

write to 0xffff8880b3388240 of 4 bytes by task 27349 on cpu 0:
 dentry_unlist fs/dcache.c:519 [inline]
 __dentry_kill+0x127/0x3b0 fs/dcache.c:575
 dentry_kill fs/dcache.c:698 [inline]
 dput+0x399/0x700 fs/dcache.c:859
 handle_mounts fs/namei.c:1375 [inline]
 step_into+0x8a3/0x1090 fs/namei.c:1676
 open_last_lookups fs/namei.c:3178 [inline]
 path_openat+0x34e/0x23d0 fs/namei.c:3343
 do_filp_open+0x11e/0x1b0 fs/namei.c:3373
 do_sys_openat2+0x52e/0x680 fs/open.c:1148
 do_sys_open+0xa2/0x110 fs/open.c:1164
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_open fs/open.c:1170 [inline]
 __se_sys_open fs/open.c:1168 [inline]
 __x64_sys_open+0x50/0x60 fs/open.c:1168
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b3388240 of 4 bytes by task 26061 on cpu 1:
 d_revalidate fs/namei.c:753 [inline]
 lookup_fast+0x176/0x3a0 fs/namei.c:1479
 open_last_lookups fs/namei.c:3121 [inline]
 path_openat+0x2ba/0x23d0 fs/namei.c:3343
 do_filp_open+0x11e/0x1b0 fs/namei.c:3373
 do_sys_openat2+0x52e/0x680 fs/open.c:1148
 do_sys_open+0xa2/0x110 fs/open.c:1164
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_open fs/open.c:1170 [inline]
 __se_sys_open fs/open.c:1168 [inline]
 __x64_sys_open+0x50/0x60 fs/open.c:1168
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26061 Comm: syz-executor.0 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (10):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/06/01 21:29 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a0331e89 .config log report
ci2-upstream-kcsan-gce 2020/05/15 06:07 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2d572622 .config log report
ci2-upstream-kcsan-gce 2020/05/05 22:35 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4b76dd25 .config log report
ci2-upstream-kcsan-gce 2020/05/04 22:27 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9941337c .config log report
ci2-upstream-kcsan-gce 2020/05/01 13:43 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 143a10e9 .config log report
ci2-upstream-kcsan-gce 2020/04/25 02:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 03d97a1b .config log report
ci2-upstream-kcsan-gce 2020/04/23 10:49 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2e44d63e .config log report
ci2-upstream-kcsan-gce 2020/03/18 19:39 https://github.com/google/ktsan.git kcsan 941e0d917bbf 0a96a13c .config log report
ci2-upstream-kcsan-gce 2020/03/06 19:37 https://github.com/google/ktsan.git kcsan 941e0d917bbf 7fb694ef .config log report
ci2-upstream-kcsan-gce 2020/02/29 12:03 https://github.com/google/ktsan.git kcsan 766d004d1b85 c88c7b75 .config log report
* Struck through repros no longer work on HEAD.