KCSAN: data-race in __dentry_kill / d_set_d

KCSAN: data-race in __dentry_kill / d_set_d_op (3)
Status: closed as invalid on 2020/06/18 14:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 511d, last: 470d

similar bugs (6):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __dentry_kill / d_set_d_op (7)	2	98d	132d	0/22	auto-closed as invalid on 2021/07/19 11:09
upstream	KCSAN: data-race in __dentry_kill / d_set_d_op (2)	9	600d	669d	0/22	auto-closed as invalid on 2020/04/08 20:57
upstream	KCSAN: data-race in __dentry_kill / d_set_d_op (5)	1	319d	287d	0/22	auto-closed as invalid on 2020/12/21 11:58
upstream	KCSAN: data-race in __dentry_kill / d_set_d_op (4)	3	400d	419d	0/22	auto-closed as invalid on 2020/09/21 06:01
upstream	KCSAN: data-race in __dentry_kill / d_set_d_op (6)	1	190d	190d	0/22	auto-closed as invalid on 2021/04/18 21:16
upstream	KCSAN: data-race in __dentry_kill / d_set_d_op	3	680d	687d	0/22	closed as invalid on 2019/11/19 14:14

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __dentry_kill / d_set_d_op

write to 0xffff88809d7c1c00 of 4 bytes by task 16002 on cpu 0:
 d_set_d_op+0x16f/0x210 fs/dcache.c:1856
 simple_lookup fs/libfs.c:71 [inline]
 simple_lookup+0x9f/0xb0 fs/libfs.c:66
 lookup_open fs/namei.c:3060 [inline]
 open_last_lookups fs/namei.c:3155 [inline]
 path_openat+0xb33/0x23d0 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 0xffff88809d7c1c00 of 4 bytes by task 17539 on cpu 1:
 dentry_unlist fs/dcache.c:544 [inline]
 __dentry_kill+0x1b4/0x3b0 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17539 Comm: syz-executor.3 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (6):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report
ci2-upstream-kcsan-gce	2020/06/07 08:27	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	e6b89e4e	.config	log	report
ci2-upstream-kcsan-gce	2020/06/07 07:50	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	e6b89e4e	.config	log	report
ci2-upstream-kcsan-gce	2020/05/20 17:25	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	4afdfa20	.config	log	report
ci2-upstream-kcsan-gce	2020/05/10 08:57	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	8742a2b9	.config	log	report
ci2-upstream-kcsan-gce	2020/05/02 23:47	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	5457883a	.config	log	report
ci2-upstream-kcsan-gce	2020/04/28 02:27	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	0ce7569e	.config	log	report