KCSAN: data-race in _prb_read_valid / prb

KCSAN: data-race in _prb_read_valid / prb_reserve
Status: moderation: reported on 2020/11/09 13:24
Reported-by: syzbot+615128043c250cbd858b@syzkaller.appspotmail.com
First crash: 188d, last: 7h14m

Sample crash report:

==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff83afcd08 of 8 bytes by task 4587 on cpu 0:
 prb_reserve+0x769/0xbc0 kernel/printk/printk_ringbuffer.c:1538
 vprintk_store+0x3e9/0x9c0 kernel/printk/printk.c:2029
 vprintk_emit+0xca/0x3d0 kernel/printk/printk.c:2081
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2115
 vprintk_func+0x137/0x140 kernel/printk/printk_safe.c:401
 printk+0x62/0x82 kernel/printk/printk.c:2146
 set_capacity_and_notify+0x15a/0x1c0 block/genhd.c:75
 loop_set_size drivers/block/loop.c:254 [inline]
 loop_configure+0xafc/0xcb0 drivers/block/loop.c:1161
 lo_ioctl+0x555/0x11f0 drivers/block/loop.c:1689
 blkdev_ioctl+0x1d0/0x3c0 block/ioctl.c:583
 block_ioctl+0x6d/0x80 fs/block_dev.c:1671
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffffffff83afcd08 of 8 bytes by task 4600 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:480 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1752 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1800 [inline]
 _prb_read_valid+0x1c9/0x8d0 kernel/printk/printk_ringbuffer.c:1880
 prb_read_valid+0x39/0x60 kernel/printk/printk_ringbuffer.c:1929
 console_unlock+0x1f7/0xbe0 kernel/printk/printk.c:2523
 do_con_write+0x5d1c/0x5d90 drivers/tty/vt/vt.c:270
 con_put_char+0x63/0x90 drivers/tty/vt/vt.c:3264
 tty_put_char+0x5f/0xa0 drivers/tty/tty_io.c:3181
 do_output_char+0x4ca/0x4f0 drivers/tty/n_tty.c:484
 process_output drivers/tty/n_tty.c:510 [inline]
 n_tty_write+0x7f8/0xaf0 drivers/tty/n_tty.c:2365
 do_tty_write drivers/tty/tty_io.c:1043 [inline]
 file_tty_write+0x409/0x660 drivers/tty/tty_io.c:1133
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1140
 call_write_iter include/linux/fs.h:1977 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_writev fs/read_write.c:939 [inline]
 do_writev+0x1e0/0x400 fs/read_write.c:982
 __do_sys_writev fs/read_write.c:1055 [inline]
 __se_sys_writev fs/read_write.c:1052 [inline]
 __x64_sys_writev+0x41/0x50 fs/read_write.c:1052
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4600 Comm: syz-executor.5 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (398):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/04/21 01:38	upstream	1fe5501b	c0ced557	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/20 08:55	upstream	7af08140	c0ced557	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/19 23:16	upstream	7af08140	4285c989	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/19 20:53	upstream	bf05bf16	4285c989	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/19 08:41	upstream	bf05bf16	50f523d7	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/18 23:55	upstream	bf05bf16	7e2b734b	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/18 10:24	upstream	c98ff1d0	7e2b734b	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/17 21:25	upstream	194cf482	7e2b734b	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/17 08:23	upstream	9cdbf646	7e2b734b	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/16 19:40	upstream	2f7b98d1	7e2b734b	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/16 13:41	upstream	7e25f40e	7e2b734b	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/16 07:24	upstream	7e25f40e	c59079a6	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/15 20:46	upstream	7f75285c	c59079a6	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/15 00:47	upstream	7f75285c	fcdb12ba	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/14 11:52	upstream	50987bec	3134b37f	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/13 22:33	upstream	eebe426d	a184b83e	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/13 20:27	upstream	89698bec	a184b83e	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/12 23:52	upstream	89698bec	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/12 09:22	upstream	d434405a	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/11 20:28	upstream	7d900724	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/11 06:59	upstream	52e44129	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/10 15:17	upstream	d4961772	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/10 02:48	upstream	4e04e751	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/09 11:57	upstream	17e7124a	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/08 23:04	upstream	3fb4f979	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/08 10:19	upstream	454859c5	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/07 21:04	upstream	3a229812	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/06 22:21	upstream	2d743660	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/05 19:31	upstream	0a50438c	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/04 23:09	upstream	e49d033b	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/04 03:09	upstream	2023a53b	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/03 15:36	upstream	d93a0d43	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/03 15:35	upstream	d93a0d43	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/02 23:53	upstream	0a84c2e4	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/02 08:19	upstream	1678e493	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/04/01 18:37	upstream	ffd9fb54	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/31 20:01	upstream	d19cc4bf	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/31 09:09	upstream	5e46d1b7	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/30 17:50	upstream	2bb25b3a	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/29 20:37	upstream	1e43c377	6a81331a	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/29 10:44	upstream	a5e13c6d	a8529b82	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/28 22:54	upstream	36a14638	a8529b82	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/27 01:43	upstream	0f4498ce	a8529b82	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/26 11:16	upstream	db24726b	a8529b82	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/25 23:36	upstream	00232240	6a383ecf	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/25 09:43	upstream	e1381380	6a383ecf	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/24 20:54	upstream	4ee998b0	607e3baf	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/03/24 13:39	upstream	7acac4b3	607e3baf	.config	log	report	info	KCSAN: data-race in _prb_read_valid / prb_reserve
ci2-upstream-kcsan-gce	2021/01/17 12:41	upstream	0da0a8a0	813be542	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/09 09:54	upstream	f8394f23	cba33199	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/07 20:52	upstream	659caaf6	cba33199	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/14 17:14	upstream	b5fc7a89	fc7735a2	.config	log	report	info