KCSAN: data-race in yama_relation_cleanup / yama_task

KCSAN: data-race in yama_relation_cleanup / yama_task_free (2)
Status: auto-closed as invalid on 2020/11/14 15:11
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 294d, last: 294d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in yama_relation_cleanup / yama_task_free (4)	2	119d	123d	0/22	auto-closed as invalid on 2021/05/17 10:12
upstream	KCSAN: data-race in yama_relation_cleanup / yama_task_free	4	365d	387d	0/22	auto-closed as invalid on 2020/09/04 02:18
upstream	KCSAN: data-race in yama_relation_cleanup / yama_task_free (3)	5	186d	236d	0/22	auto-closed as invalid on 2021/03/02 05:29

Sample crash report:

==================================================================
BUG: KCSAN: data-race in yama_relation_cleanup / yama_task_free

write to 0xffff88811ea33010 of 1 bytes by interrupt on cpu 1:
 yama_ptracer_del security/yama/yama_lsm.c:191 [inline]
 yama_task_free+0xc6/0x150 security/yama/yama_lsm.c:207
 security_task_free+0x3f/0xa0 security/security.c:1595
 __put_task_struct+0x96/0x370 kernel/fork.c:733
 put_task_struct include/linux/sched/task.h:113 [inline]
 delayed_put_task_struct+0x4b/0x150 kernel/exit.c:172
 rcu_do_batch kernel/rcu/tree.c:2430 [inline]
 rcu_core+0x5a6/0xb30 kernel/rcu/tree.c:2658
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2667
 __do_softirq+0x198/0x360 kernel/softirq.c:298
 run_ksoftirqd+0x2f/0x60 kernel/softirq.c:652
 smpboot_thread_fn+0x347/0x530 kernel/smpboot.c:165
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff88811ea33010 of 1 bytes by task 5059 on cpu 0:
 yama_relation_cleanup+0x5d/0x150 security/yama/yama_lsm.c:122
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5059 Comm: kworker/0:2 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events yama_relation_cleanup
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2020/10/10 15:03	upstream	6f2f486d57c4	b74c49a6	.config	log	report			info