KCSAN: data-race in ext4_setattr / mpage_process_page

KCSAN: data-race in ext4_setattr / mpage_process_page_bufs (2)
Status: moderation: reported on 2020/09/21 10:22
Reported-by: syzbot+d8c674e306c5fd82145e@syzkaller.appspotmail.com
First crash: 401d, last: 2d02h

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs				35	414d	637d	0/22	closed as invalid on 2020/06/18 14:24

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_setattr / mpage_process_page_bufs

write to 0xffff888106ea6210 of 8 bytes by task 10240 on cpu 0:
 i_size_write include/linux/fs.h:871 [inline]
 ext4_setattr+0xd54/0xec0 fs/ext4/inode.c:5481
 notify_change+0x8a3/0xa80 fs/attr.c:398
 do_truncate+0xe8/0x130 fs/open.c:64
 handle_truncate fs/namei.c:3030 [inline]
 do_open fs/namei.c:3378 [inline]
 path_openat+0x19b2/0x1f20 fs/namei.c:3507
 do_filp_open+0xe9/0x200 fs/namei.c:3534
 do_sys_openat2+0xa3/0x250 fs/open.c:1204
 do_sys_open fs/open.c:1220 [inline]
 __do_sys_openat fs/open.c:1236 [inline]
 __se_sys_openat fs/open.c:1231 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1231
 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 0xffff888106ea6210 of 8 bytes by task 10238 on cpu 1:
 i_size_read include/linux/fs.h:849 [inline]
 mpage_process_page_bufs+0x34/0x560 fs/ext4/inode.c:2192
 mpage_prepare_extent_to_map+0x4e6/0x640 fs/ext4/inode.c:2626
 ext4_writepages+0x9d8/0x1d10 fs/ext4/inode.c:2798
 do_writepages+0x7b/0x150 mm/page-writeback.c:2355
 __filemap_fdatawrite_range mm/filemap.c:413 [inline]
 __filemap_fdatawrite mm/filemap.c:421 [inline]
 filemap_flush+0x132/0x160 mm/filemap.c:448
 ext4_alloc_da_blocks+0x47/0xd0 fs/ext4/inode.c:3164
 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:141
 __fput+0x25b/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:212 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0xf8/0x190 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x49/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000005ba000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10238 Comm: syz-executor.2 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (203):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/07/30 08:00	upstream	764a5bc89b12	c585c7b0	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/29 03:28	upstream	4010a528219e	9a4781d4	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/24 15:45	upstream	f0fddcec6b62	4d1b57d4	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/17 21:37	upstream	d980cc0620ae	f115ae98	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/16 03:38	upstream	dd9c7df94c1b	f115ae98	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/15 07:44	upstream	8096acd7442e	b9a2f64e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/13 21:49	upstream	40226a3d96ef	70168d5c	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/13 13:15	upstream	7fef2edf7cc7	70168d5c	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/12 09:03	upstream	e73f0f0ee754	a4869c92	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/09 09:06	upstream	3dbdb38e2869	281e815f	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/07 09:13	upstream	3dbdb38e2869	4846d5c1	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/07/01 04:07	upstream	df04fbe8680b	38a885d1	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/28 14:26	upstream	62fb9874f5da	9d2ab5df	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/28 09:42	upstream	b4b27b9eed8e	9d2ab5df	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/21 10:47	upstream	13311e74253f	aba2b2fb	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/09 17:43	upstream	368094df48e6	84fe5d96	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/08 07:05	upstream	614124bea77e	b718257f	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/06 00:34	upstream	f5b6eb1e0182	500c2339	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/06/02 05:04	upstream	231bc5390667	032639db	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/31 05:18	upstream	8124c8a6b353	325a8dab	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/29 09:37	upstream	6799d4f2da49	858ea628	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/28 11:53	upstream	97e5bf604b7a	858ea628	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/25 17:49	upstream	a050a6d2b7e8	93d3a9f6	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/25 04:32	upstream	1434a3127887	3c7fef33	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/23 15:54	upstream	4d7620341eda	3c7fef33	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/23 00:12	upstream	23d729263037	3c7fef33	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/22 14:43	upstream	45af60e7ced0	3c7fef33	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/21 13:51	upstream	ba816d3c265c	3c7fef33	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/20 13:34	upstream	c3d0e3fd41b7	c560a65d	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/19 18:28	upstream	c3d0e3fd41b7	a343ba6b	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/19 06:48	upstream	8ac91e6c6033	a343ba6b	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/17 15:54	upstream	d07f6ca923ea	a2eb125d	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/15 13:39	upstream	25a1298726e9	93f844de	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/14 18:27	upstream	bd3c9cdb21a2	8bdd5343	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/10 01:48	upstream	9819f682e48c	bc5434be	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/08 06:32	upstream	1ad77a05cfae	bc5434be	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/05/04 21:05	upstream	5e321ded302d	06c27ff5	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/29 08:20	upstream	68a32ba14177	77e2b668	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/27 00:01	upstream	9f4ad9e425a1	8ee2dea6	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/24 02:01	upstream	8db5efb83fa9	17f0b706	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/23 23:44	upstream	18a3c5f7abfd	17f0b706	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/22 08:19	upstream	16fc44d6387e	2bc8999a	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/20 21:41	upstream	7af08140979a	c0ced557	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/04/16 23:09	upstream	2f7b98d1e55c	7e2b734b	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/16 19:59	upstream	1d94330a437a	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/20 14:30	upstream	325d0eab4f31	9564d2e9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/18 14:08	upstream	10b82d517648	38962c8b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/06/26 02:37	upstream	4a21185cda0f	aea82c00	.config	log	report