KCSAN: data-race in ext4_write_end / mpage_process_page

KCSAN: data-race in ext4_write_end / mpage_process_page_bufs (3)
Status: moderation: reported on 2020/12/06 12:03
Reported-by: syzbot+7267bfaa83b92bf97546@syzkaller.appspotmail.com
First crash: 298d, last: 6h36m

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs				1	479d	479d	0/22	auto-closed as invalid on 2020/03/01 21:02
upstream	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs (2)				6	318d	388d	0/22	closed as invalid on 2020/06/18 14:24

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_write_end / mpage_process_page_bufs

write to 0xffff888101b881d0 of 8 bytes by task 21995 on cpu 0:
 i_size_write include/linux/fs.h:872 [inline]
 ext4_update_inode_size fs/ext4/ext4.h:3292 [inline]
 ext4_write_end+0x1fe/0xa00 fs/ext4/inode.c:1311
 ext4_da_write_end+0x93/0x760 fs/ext4/inode.c:3081
 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3586
 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:269
 ext4_file_write_iter+0x48a/0x10b0 fs/ext4/file.c:502
 call_write_iter include/linux/fs.h:1977 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x6f9/0x7e0 fs/read_write.c:605
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888101b881d0 of 8 bytes by task 22009 on cpu 1:
 i_size_read include/linux/fs.h:850 [inline]
 mpage_process_page_bufs+0x34/0x5f0 fs/ext4/inode.c:2194
 mpage_prepare_extent_to_map+0x4e6/0x640 fs/ext4/inode.c:2628
 ext4_writepages+0x97b/0x1e70 fs/ext4/inode.c:2800
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:424
 file_write_and_wait_range+0x9f/0x120 mm/filemap.c:763
 ext4_sync_file+0x105/0x6e0 fs/ext4/fsync.c:151
 vfs_fsync_range fs/sync.c:200 [inline]
 vfs_fsync fs/sync.c:214 [inline]
 do_fsync fs/sync.c:224 [inline]
 __do_sys_fdatasync fs/sync.c:237 [inline]
 __se_sys_fdatasync fs/sync.c:235 [inline]
 __x64_sys_fdatasync+0x7a/0xd0 fs/sync.c:235
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22009 Comm: syz-executor.4 Tainted: G        W         5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (74):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/04/15 01:28	upstream	7f75285c	fcdb12ba	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/13 23:07	upstream	eebe426d	a184b83e	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/12 23:50	upstream	89698bec	6a81331a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/10 02:26	upstream	4e04e751	6a81331a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/09 13:13	upstream	17e7124a	6a81331a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/08 09:48	upstream	454859c5	6a81331a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/04 03:35	upstream	2023a53b	6a81331a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/03/29 22:03	upstream	1e43c377	6a81331a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/03/29 11:54	upstream	a5e13c6d	a8529b82	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/03/23 21:13	upstream	7acac4b3	e613994b	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/03/21 01:14	upstream	812da4d3	17810eae	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/03/14 23:58	upstream	75013c6c	cc1cff8f	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/03/13 00:33	upstream	f296bfd5	429d8a6b	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/19 15:48	upstream	f40ddce8	f689d40a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/19 00:47	upstream	f40ddce8	14052202	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/14 12:43	upstream	358fecee	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/14 02:18	upstream	ac30d8ce	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/13 10:21	upstream	c6d8570e	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/12 07:48	upstream	dcc0b490	a5f86b15	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/11 18:59	upstream	291009f6	a5f86b15	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/10 22:04	upstream	291009f6	a52ee10a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/08 22:05	upstream	e0756cfc	2bd9619f	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/06 06:16	upstream	1e0d27fc	23a562df	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/01 04:26	upstream	1048ba83	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/29 22:11	upstream	bec4c296	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/24 20:03	upstream	e6806137	52e37319	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/21 15:25	upstream	9791581c	d4f4eca5	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/17 07:34	upstream	54c6247d	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/15 17:47	upstream	5ee88057	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/09 23:53	upstream	2ff90100	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/05 21:12	upstream	6207214a	a0234d98	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/04 04:55	upstream	e71ba945	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/01 18:06	upstream	f6e1ea19	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/28 06:57	upstream	5c8fe583	2242f77f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/27 22:30	upstream	f838f8d2	2242f77f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/21 13:43	upstream	e37b12e4	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/14 20:14	upstream	2c85ebc5	97183ed7	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/13 22:05	upstream	ec6f5e0e	8f160dd5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/10 00:46	upstream	ca4bbdaf	c090b4da	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/09 06:19	upstream	7d8761ba	40cc414d	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/03 19:14	upstream	34816d20	59ad4022	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/01 12:04	upstream	b6505459	07bfe8a5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/30 13:32	upstream	b6505459	76831598	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/27 01:37	upstream	4df91062	5018c946	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/25 21:37	upstream	fa02fcd9	3f581b43	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/20 17:50	upstream	4d02da97	68068804	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/18 13:49	upstream	0fa8ee0d	09323409	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/18 21:13	upstream	9453b2d4	fea47c01	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/15 00:58	upstream	3e4fb434	fc7735a2	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/12 17:44	upstream	bbf5c979	d32b0bbf	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/10 14:46	upstream	6f2f486d	b74c49a6	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/07 11:17	upstream	c85fb28b	1880b4a9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/29 11:11	upstream	fb0155a0	1b88c6d5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/20 10:17	upstream	325d0eab	53ce8104	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/19 23:43	upstream	eb5f95f1	53ce8104	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/19 12:38	upstream	eb5f95f1	53ce8104	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/18 06:55	upstream	4cbffc46	8247808b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/16 13:31	upstream	fc4f28bb	77507d02	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/13 23:16	upstream	84b13499	2d3cdd63	.config	log	report
ci2-upstream-kcsan-gce	2020/09/02 11:15	upstream	b765a32a	abf9ba4f	.config	log	report
ci2-upstream-kcsan-gce	2020/08/27 02:31	upstream	15bc20c6	318430cb	.config	log	report
ci2-upstream-kcsan-gce	2020/08/15 11:04	upstream	c9c9735c	5ce13532	.config	log	report
ci2-upstream-kcsan-gce	2020/08/07 02:23	upstream	d6efb3ac	cb436c69	.config	log	report
ci2-upstream-kcsan-gce	2020/08/05 11:38	upstream	c0842fbc	b7129355	.config	log	report
ci2-upstream-kcsan-gce	2020/07/18 05:40	upstream	6a70f89c	9c812472	.config	log	report
ci2-upstream-kcsan-gce	2020/07/14 22:30	upstream	e9919e11	6f458026	.config	log	report
ci2-upstream-kcsan-gce	2020/07/12 09:11	upstream	0aea6d5c	115e1930	.config	log	report
ci2-upstream-kcsan-gce	2020/07/09 19:51	upstream	0bddd227	edf162e8	.config	log	report
ci2-upstream-kcsan-gce	2020/07/08 14:00	upstream	dcde237b	5962a2dc	.config	log	report
ci2-upstream-kcsan-gce	2020/07/08 03:34	upstream	aa27b32b	08fc4ef1	.config	log	report
ci2-upstream-kcsan-gce	2020/07/01 19:15	upstream	7c30b859	39acb39d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/28 19:13	upstream	719fdd32	a2cdad9d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 11:15	upstream	3e08a952	41694dbf	.config	log	report
ci2-upstream-kcsan-gce	2020/06/20 12:49	upstream	672f9255	c655ec77	.config	log	report