KCSAN: data-race in ps2_do_sendbyte / ps2_handle

KCSAN: data-race in ps2_do_sendbyte / ps2_handle_ack (2)
Status: auto-closed as invalid on 2020/08/28 23:47
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 561d, last: 542d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ps2_do_sendbyte / ps2_handle_ack				6	657d	722d	0/22	auto-closed as invalid on 2020/06/09 05:57
upstream	KCSAN: data-race in ps2_do_sendbyte / ps2_handle_ack (3)				172	2d00h	406d	0/22	moderation: reported on 2020/12/07 11:53

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ps2_do_sendbyte / ps2_handle_ack

write to 0xffff8881289cb040 of 8 bytes by interrupt on cpu 1:
 ps2_handle_ack+0x15a/0x350 drivers/input/serio/libps2.c:439
 atkbd_interrupt+0xbf1/0xcd0 drivers/input/keyboard/atkbd.c:434
 serio_interrupt+0x5d/0xe0 drivers/input/serio/serio.c:1002
 i8042_interrupt+0x39e/0x720 drivers/input/serio/i8042.c:598
 __handle_irq_event_percpu+0x16e/0x4f0 kernel/irq/handle.c:156
 handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
 handle_irq_event+0x94/0x140 kernel/irq/handle.c:213
 handle_edge_irq+0x18e/0x5f0 kernel/irq/chip.c:830
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 handle_irq arch/x86/kernel/irq.c:230 [inline]
 __common_interrupt arch/x86/kernel/irq.c:249 [inline]
 common_interrupt+0xf6/0x1e0 arch/x86/kernel/irq.c:239
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:576
 is_atomic kernel/kcsan/core.c:229 [inline]
 should_watch kernel/kcsan/core.c:257 [inline]
 check_access kernel/kcsan/core.c:581 [inline]
 __tsan_read4+0x11a/0x180 kernel/kcsan/core.c:776
 rcu_preempt_read_exit kernel/rcu/tree_plugin.h:359 [inline]
 __rcu_read_unlock+0x25/0x260 kernel/rcu/tree_plugin.h:392
 rcu_read_unlock include/linux/rcupdate.h:687 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline]
 batadv_nc_worker+0xea/0xa00 net/batman-adv/network-coding.c:718
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

read to 0xffff8881289cb040 of 8 bytes by task 4736 on cpu 0:
 ps2_do_sendbyte+0x1a1/0x380 drivers/input/serio/libps2.c:45
 __ps2_command+0x30d/0x9f0 drivers/input/serio/libps2.c:273
 ps2_command+0x50/0x90 drivers/input/serio/libps2.c:332
 atkbd_set_repeat_rate drivers/input/keyboard/atkbd.c:595 [inline]
 atkbd_event_work+0x2b6/0x2f0 drivers/input/keyboard/atkbd.c:649
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4736 Comm: kworker/0:3 Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events atkbd_event_work
==================================================================

Crashes (4):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report
ci2-upstream-kcsan-gce	2020/07/24 23:38	upstream	68845a55c31b	0a13649c	.config	log	report
ci2-upstream-kcsan-gce	2020/07/08 14:53	upstream	dcde237b9b0e	5962a2dc	.config	log	report
ci2-upstream-kcsan-gce	2020/07/05 17:32	upstream	35e884f89df4	22f87567	.config	log	report
ci2-upstream-kcsan-gce	2020/07/05 11:24	upstream	35e884f89df4	24d7f505	.config	log	report