syzbot


KCSAN: data-race in d_alloc_parallel / d_set_d_op (7)

Status: auto-closed as invalid on 2022/07/28 05:03
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 223d, last: 167d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in d_alloc_parallel / d_set_d_op (4) 1 674d 674d 0/24 auto-closed as invalid on 2021/03/08 01:09
upstream KCSAN: data-race in d_alloc_parallel / d_set_d_op 23 971d 1135d 0/24 auto-closed as invalid on 2020/06/18 13:33
upstream KCSAN: data-race in d_alloc_parallel / d_set_d_op (2) 1 834d 834d 0/24 auto-closed as invalid on 2020/09/29 03:57
upstream KCSAN: data-race in d_alloc_parallel / d_set_d_op (6) 3 260d 306d 0/24 auto-closed as invalid on 2022/04/26 06:41
upstream KCSAN: data-race in d_alloc_parallel / d_set_d_op (3) 2 738d 730d 0/24 auto-closed as invalid on 2021/01/03 18:19
upstream KCSAN: data-race in d_alloc_parallel / d_set_d_op (5) 13 544d 633d 0/24 auto-closed as invalid on 2021/07/16 11:19

Sample crash report:
==================================================================
BUG: KCSAN: data-race in d_alloc_parallel / d_set_d_op

read-write to 0xffff88811f314240 of 4 bytes by task 20684 on cpu 0:
 d_set_d_op+0xf0/0x1e0 fs/dcache.c:1932
 proc_pident_instantiate+0x164/0x180 fs/proc/base.c:2625
 proc_pident_lookup fs/proc/base.c:2648 [inline]
 proc_tgid_base_lookup+0x10c/0x180 fs/proc/base.c:3331
 __lookup_slow+0x182/0x250 fs/namei.c:1701
 lookup_slow+0x3c/0x60 fs/namei.c:1718
 walk_component+0x23d/0x280 fs/namei.c:2014
 link_path_walk+0x459/0x7a0
 path_openat+0x199/0x1b30 fs/namei.c:3649
 do_filp_open+0x105/0x220 fs/namei.c:3680
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1278
 do_sys_open fs/open.c:1294 [inline]
 __do_sys_openat fs/open.c:1310 [inline]
 __se_sys_openat fs/open.c:1305 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1305
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff88811f314240 of 4 bytes by task 20683 on cpu 1:
 d_in_lookup include/linux/dcache.h:356 [inline]
 d_wait_lookup fs/dcache.c:2582 [inline]
 d_alloc_parallel+0x655/0xcc0 fs/dcache.c:2670
 __lookup_slow+0x80/0x250 fs/namei.c:1686
 lookup_slow+0x3c/0x60 fs/namei.c:1718
 walk_component+0x23d/0x280 fs/namei.c:2014
 link_path_walk+0x459/0x7a0
 path_openat+0x199/0x1b30 fs/namei.c:3649
 do_filp_open+0x105/0x220 fs/namei.c:3680
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1278
 do_sys_open fs/open.c:1294 [inline]
 __do_sys_openat fs/open.c:1310 [inline]
 __se_sys_openat fs/open.c:1305 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1305
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x10000000 -> 0x1000000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20683 Comm: syz-executor.4 Not tainted 5.19.0-rc3-syzkaller-00043-g3abc3ae553c7-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/06/23 04:59 upstream 3abc3ae553c7 912f5df7 .config log report info KCSAN: data-race in d_alloc_parallel / d_set_d_op
ci2-upstream-kcsan-gce 2022/06/02 06:31 upstream 8eca6b0a647a b4bc6a3d .config log report info KCSAN: data-race in d_alloc_parallel / d_set_d_op
ci2-upstream-kcsan-gce 2022/05/05 16:23 upstream a7391ad35724 b3f09415 .config log report info KCSAN: data-race in d_alloc_parallel / d_set_d_op
ci2-upstream-kcsan-gce 2022/04/28 07:37 upstream 8f4dd16603ce 8a1f1f07 .config log report info KCSAN: data-race in d_alloc_parallel / d_set_d_op
* Struck through repros no longer work on HEAD.