KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf

KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common (2)
Status: moderation: reported on 2020/12/07 11:24
Reported-by: syzbot+d6065a91a5cacf554489@syzkaller.appspotmail.com
First crash: 398d, last: 19d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common				19	415d	643d	0/22	closed as invalid on 2020/06/18 14:24

Sample crash report:

==================================================================
BUG: KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common

write to 0xffffc9000e495000 of 8 bytes by task 24434 on cpu 1:
 put_tty_queue drivers/tty/n_tty.c:316 [inline]
 n_tty_receive_char_fast drivers/tty/n_tty.c:1448 [inline]
 n_tty_receive_buf_fast drivers/tty/n_tty.c:1606 [inline]
 __receive_buf drivers/tty/n_tty.c:1641 [inline]
 n_tty_receive_buf_common+0x1465/0x1e20 drivers/tty/n_tty.c:1740
 n_tty_receive_buf+0x2b/0x40 drivers/tty/n_tty.c:1769
 tiocsti drivers/tty/tty_io.c:2315 [inline]
 tty_ioctl+0x968/0x1120 drivers/tty/tty_io.c:2721
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffffc9000e495000 of 8 bytes by task 1775 on cpu 0:
 n_tty_receive_char_fast drivers/tty/n_tty.c:1443 [inline]
 n_tty_receive_buf_fast drivers/tty/n_tty.c:1606 [inline]
 __receive_buf drivers/tty/n_tty.c:1641 [inline]
 n_tty_receive_buf_common+0x1145/0x1e20 drivers/tty/n_tty.c:1740
 n_tty_receive_buf2+0x2e/0x40 drivers/tty/n_tty.c:1775
 tty_ldisc_receive_buf+0x5b/0xf0 drivers/tty/tty_buffer.c:461
 tty_port_default_receive_buf+0x54/0x80 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:481 [inline]
 flush_to_ldisc+0x1c5/0x2c0 drivers/tty/tty_buffer.c:533
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

value changed: 0x0000000000000127 -> 0x0000000000000128

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1775 Comm: kworker/u4:6 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
==================================================================

Crashes (86):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/07/08 18:45	upstream	3dbdb38e2869	1b20171a	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/07/07 19:11	upstream	3dbdb38e2869	95793bce	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/07/02 11:46	upstream	3dbdb38e2869	658ebc66	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/06/21 10:18	upstream	13311e74253f	aba2b2fb	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/06/12 15:04	upstream	ad347abe4a98	1ba81399	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/31 09:18	upstream	8124c8a6b353	032639db	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/29 17:36	upstream	f956cb99b938	325a8dab	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/29 08:33	upstream	6799d4f2da49	858ea628	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/25 16:51	upstream	a050a6d2b7e8	93d3a9f6	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/22 04:47	upstream	45af60e7ced0	3c7fef33	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/15 07:33	upstream	25a1298726e9	8bdd5343	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/06 10:45	upstream	8404c9fbc84b	06c27ff5	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/05/05 07:31	upstream	d665ea6ea86c	06c27ff5	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/04/16 05:40	upstream	7e25f40eab52	c59079a6	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/04/13 21:42	upstream	eebe426d32e1	a184b83e	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/04/12 09:40	upstream	d434405aaab7	6a81331a	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/03/29 20:11	upstream	1e43c377a79f	6a81331a	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/03/23 07:53	upstream	84196390620a	8092f30d	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/03/13 03:24	upstream	f296bfd5cd04	429d8a6b	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/02/22 07:32	upstream	31caf8b2a847	a659b3f1	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/02/05 13:08	upstream	dd86e7fa07a3	23a562df	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/02/02 23:03	upstream	3aaf0a27ffc2	624dad51	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/02/01 16:56	upstream	1048ba83fb1c	e6b95f32	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/01/26 17:38	upstream	13391c60da33	55a7d4df	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/01/23 00:48	upstream	83d09ad4b950	52e37319	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/01/20 22:11	upstream	75439bc439e0	d4f4eca5	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/01/18 14:53	upstream	19c329f68089	63631df1	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/01/18 04:43	upstream	19c329f68089	fd103621	.config	log	report	info	KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common
ci2-upstream-kcsan-gce	2021/01/12 00:32	upstream	a0d54b4f5b21	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/10 02:08	upstream	2ff90100ace8	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/07 21:33	upstream	f5e6c330254a	c104d4a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/05 21:14	upstream	6207214a70bf	a0234d98	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/05 11:38	upstream	36bbbd0e234d	a0234d98	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/04 22:25	upstream	36bbbd0e234d	2a28ff1f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/29 14:13	upstream	dea8dcf2a9fa	80910769	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/28 21:36	upstream	c76e02c59e13	8259d56c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/23 12:12	upstream	614cb5894306	c2c1d1dd	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/19 01:49	upstream	3644e2d2dda7	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/18 01:46	upstream	d64c6f96ba86	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/17 09:58	upstream	accefff5b547	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/16 10:06	upstream	d01e7f10dae2	649595c6	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/15 10:46	upstream	148842c98a24	97183ed7	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/13 09:34	upstream	6bff9bb8a292	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/12 01:33	upstream	7f376f1917d7	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/11 01:33	upstream	9fca90cf2892	f900b48c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/08 10:02	upstream	cd796ed33450	9af51e31	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/29 00:13	upstream	67f34fa8893e	a0092f9d	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/15 18:41	upstream	0062442ecfef	1bf9a662	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/06 22:43	upstream	bf3e76289cd2	cba33199	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/05 20:21	upstream	9322c47b21b9	abf9ba4f	.config	log	report
ci2-upstream-kcsan-gce	2020/08/26 13:42	upstream	2ac69819ba9e	318430cb	.config	log	report
ci2-upstream-kcsan-gce	2020/08/24 12:20	upstream	d012a7190fc1	67b599d1	.config	log	report
ci2-upstream-kcsan-gce	2020/08/24 00:03	upstream	cb95712138ec	cef5ae68	.config	log	report
ci2-upstream-kcsan-gce	2020/08/23 20:23	upstream	cb95712138ec	a6d5f3ad	.config	log	report
ci2-upstream-kcsan-gce	2020/08/22 20:25	upstream	c3d8f220d012	1da71ab0	.config	log	report
ci2-upstream-kcsan-gce	2020/08/21 18:52	upstream	cd02217a5d81	6436ce4b	.config	log	report
ci2-upstream-kcsan-gce	2020/08/17 03:30	upstream	2cc3c4b3c2e9	5ce13532	.config	log	report
ci2-upstream-kcsan-gce	2020/08/14 01:51	upstream	990f227371a4	54ce1ed6	.config	log	report
ci2-upstream-kcsan-gce	2020/08/13 10:05	upstream	fb893de323e2	bc15f7db	.config	log	report
ci2-upstream-kcsan-gce	2020/08/07 12:15	upstream	86cfccb66937	28ac5c9e	.config	log	report
ci2-upstream-kcsan-gce	2020/07/17 18:52	upstream	8882572675c1	9c812472	.config	log	report
ci2-upstream-kcsan-gce	2020/07/08 22:23	upstream	63e1968a2c87	9f9845eb	.config	log	report
ci2-upstream-kcsan-gce	2020/06/29 06:37	upstream	9ebcfadb0610	0375051c	.config	log	report
ci2-upstream-kcsan-gce	2020/06/26 03:03	upstream	4a21185cda0f	aea82c00	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 20:04	upstream	26e122e97a3d	9d60b18e	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 18:40	upstream	26e122e97a3d	41694dbf	.config	log	report