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: 527d, last: 5h55m

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	708d	708d	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	547d	617d	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 0xffff8881440a2b08 of 8 bytes by task 8007 on cpu 1:
 i_size_write include/linux/fs.h:913 [inline]
 ext4_update_inode_size fs/ext4/ext4.h:3422 [inline]
 ext4_write_end+0x16d/0x710 fs/ext4/inode.c:1303
 ext4_da_write_end+0x6d/0x630 fs/ext4/inode.c:3026
 generic_perform_write+0x261/0x400 mm/filemap.c:3767
 ext4_buffered_write_iter+0x25b/0x380 fs/ext4/file.c:269
 ext4_file_write_iter+0x2e7/0x1200
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881440a2b08 of 8 bytes by task 8006 on cpu 0:
 i_size_read include/linux/fs.h:891 [inline]
 mpage_process_page_bufs+0x34/0x560 fs/ext4/inode.c:2187
 mpage_prepare_extent_to_map+0x4f6/0x650 fs/ext4/inode.c:2621
 ext4_writepages+0xa78/0x1e80 fs/ext4/inode.c:2793
 do_writepages+0x1cb/0x330 mm/page-writeback.c:2364
 filemap_fdatawrite_wbc mm/filemap.c:407 [inline]
 __filemap_fdatawrite_range mm/filemap.c:440 [inline]
 __filemap_fdatawrite mm/filemap.c:446 [inline]
 filemap_flush+0xd7/0x100 mm/filemap.c:473
 ext4_alloc_da_blocks+0x47/0x100 fs/ext4/inode.c:3103
 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:141
 __fput+0x295/0x520 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x160/0x190 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000000016b000 -> 0x000000000016c000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8006 Comm: syz-executor.4 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (148):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/11/29 22:07	upstream	d58071a8a76d	d0830353	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/11 15:02	upstream	debe436e77c7	75b04091	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/07 23:04	upstream	b5013d084e03	4c1be0be	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/06 04:09	upstream	fe91c4725aee	4c1be0be	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/28 12:10	upstream	1fc596a56b33	be531bb4	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/27 12:08	upstream	d25f27432f80	d50eb50a	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/23 13:00	upstream	9c0c4d24ac00	282f03fb	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/21 00:04	upstream	2f111a6fd5b5	f111d03b	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/12 22:42	upstream	f4d0cc426f77	08362356	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/12 07:05	upstream	fa5878760579	838e7e2c	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/11 03:31	upstream	efb52a7d9511	838e7e2c	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/08 15:10	upstream	1da38549dd64	efe0f24d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/02 21:14	upstream	ab2a7a35c4e7	db0f5787	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/30 22:55	upstream	4de593fb965f	0f01403d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/30 00:26	upstream	02d5e016800d	be530f6c	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/29 05:53	upstream	a4e6f95a891a	d82cb927	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/27 17:21	upstream	5816b3e6577e	78494d16	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/22 08:42	upstream	92477dd1faa6	169724fe	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/18 15:43	upstream	4357f03d6611	70b76c1d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/18 00:44	upstream	ddf21bd8ab98	70b76c1d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/17 10:27	upstream	bdb575f87217	5b989942	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/12 20:42	upstream	78e709522d2c	3ce60af8	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/12 09:29	upstream	c605c39677b9	3ce60af8	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/07 12:08	upstream	4b93c544e90e	6ca60148	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/05 16:23	upstream	a9c9a6f741cd	d236a457	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/29 18:59	upstream	3f5ad13cb012	be2c130d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/28 18:13	upstream	64b4fc45bea6	be2c130d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/27 14:03	upstream	77dd11439b86	b318694d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/27 08:20	upstream	1a6d80ff2419	b318694d	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/26 04:58	upstream	fe67f4dd8daa	b599f2fc	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/22 06:26	upstream	002c0aef1090	b599f2fc	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/19 18:22	upstream	d6d09a694205	e2da378b	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/13 10:58	upstream	f8e6dfc64f61	3fd2ea69	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/08 12:17	upstream	85a90500f9a1	6972b106	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/04 18:32	upstream	d5ad8ec3cfb5	b97d64c9	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/03 12:36	upstream	c500bee1c5b2	6c236867	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/08/01 03:15	upstream	f3438b4c4e69	6c236867	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/31 20:39	upstream	c7d102232649	6c236867	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/30 08:05	upstream	764a5bc89b12	c585c7b0	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/27 07:57	upstream	ff1176468d36	fd511809	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/23 11:00	upstream	9bead1b58c4c	bc5f1d88	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/22 10:12	upstream	3d5895cd3517	29c3f20f	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/20 16:33	upstream	8cae8cd89f05	1b201b48	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/02 18:24	upstream	3dbdb38e2869	55aa55c2	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/28 23:26	upstream	62fb9874f5da	9d2ab5df	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/27 19:15	upstream	625acffd7ae2	9d2ab5df	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/26 00:13	upstream	44db63d1ad8d	ae6bf8dd	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/22 02:27	upstream	a96bfed64c89	aba2b2fb	.config	log	report	info	KCSAN: data-race in ext4_write_end / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/20 18:43	upstream	cba5e97280f5	aba2b2fb	.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	54c6247d06f1	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/03 19:14	upstream	34816d20f173	59ad4022	.config	log	report	info
ci2-upstream-kcsan-gce	2020/06/20 12:49	upstream	672f9255a727	c655ec77	.config	log	report