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: 522d, last: 1d18h

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	535d	758d	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 0xffff88812c567b88 of 8 bytes by task 27634 on cpu 1:
 i_size_write include/linux/fs.h:913 [inline]
 ext4_setattr+0xd7e/0xf20 fs/ext4/inode.c:5451
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate+0xf7/0x140 fs/open.c:64
 handle_truncate fs/namei.c:3082 [inline]
 do_open fs/namei.c:3430 [inline]
 path_openat+0x191f/0x1eb0 fs/namei.c:3559
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_creat fs/open.c:1304 [inline]
 __se_sys_creat fs/open.c:1298 [inline]
 __x64_sys_creat+0x62/0x80 fs/open.c:1298
 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 0xffff88812c567b88 of 8 bytes by task 27633 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: 0x000000000036ea01 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 27633 Comm: syz-executor.4 Tainted: G        W         5.16.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (262):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/11/28 08:53	upstream	3498e7f2bb41	63eeac02	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/27 22:31	upstream	741392771338	63eeac02	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/25 05:00	upstream	5f53fa508db0	545ab074	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/24 10:58	upstream	5d9f4cf36721	545ab074	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/21 08:35	upstream	61564e7b3abc	4eb20a4e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/18 19:26	upstream	42eb8fdac2fc	31a30fc0	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/18 08:50	upstream	42eb8fdac2fc	cafff8b6	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/16 20:32	upstream	8ab774587903	600426bd	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/15 17:13	upstream	8ab774587903	75b04091	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/15 05:47	upstream	ce49bfc8d037	75b04091	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/11 12:22	upstream	debe436e77c7	75b04091	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/09 23:09	upstream	d2f38a3c6507	59bcaf9a	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/06 02:26	upstream	fe91c4725aee	4c1be0be	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/03 17:05	upstream	dcd68326d29b	4c1be0be	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/11/01 11:08	upstream	8bb7eca972ad	098b5d53	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/31 04:15	upstream	119c85055d86	098b5d53	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/24 00:04	upstream	9c0c4d24ac00	282f03fb	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/20 20:05	upstream	d9abdee5fd5a	418a00eb	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/17 05:36	upstream	304040fb4909	0c5d9412	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/15 02:18	upstream	26d657410983	7aa5fe41	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/12 15:26	upstream	fa5878760579	08362356	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/11 14:18	upstream	64570fbc14f8	838e7e2c	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/09 14:55	upstream	5d6ab0bb408f	838e7e2c	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/04 04:21	upstream	6761a0ae9895	db0f5787	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/03 01:48	upstream	ab2a7a35c4e7	db0f5787	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/10/01 09:09	upstream	4de593fb965f	1d849ab4	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/30 03:48	upstream	02d5e016800d	be530f6c	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/28 01:21	upstream	0513e464f900	78494d16	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/26 22:26	upstream	996148ee05d0	78494d16	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/26 16:10	upstream	a3b397b4fffb	8cac236e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/23 21:42	upstream	f10f0481a5b5	8cac236e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/21 21:48	upstream	d9fb678414c0	169724fe	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/21 06:00	upstream	e8f71f89236e	af796c18	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/20 00:12	upstream	20621d2f27a0	70b76c1d	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/19 21:41	upstream	d4d016caa4b8	70b76c1d	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/18 06:14	upstream	4357f03d6611	70b76c1d	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/17 17:32	upstream	ddf21bd8ab98	70b76c1d	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/14 17:15	upstream	1619b69edce1	07e953c1	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/14 09:20	upstream	d0ee23f9d78b	58d09404	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/14 06:55	upstream	316346243be6	58d09404	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/10 05:30	upstream	bf9f243f23e6	e2776ee4	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/09 17:23	upstream	a3fa7a101dcf	e2776ee4	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/09/07 23:52	upstream	0bcfe68b8767	064c9eb7	.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