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: 249d, last: 9d16h

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	262d	485d	0/21	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 0xffff888020597b50 of 8 bytes by task 6970 on cpu 0:
 i_size_write include/linux/fs.h:870 [inline]
 ext4_setattr+0xe19/0xf60 fs/ext4/inode.c:5483
 notify_change+0x86d/0xa60 fs/attr.c:336
 do_truncate+0xe0/0x120 fs/open.c:64
 handle_truncate fs/namei.c:2912 [inline]
 do_open fs/namei.c:3258 [inline]
 path_openat+0x1a30/0x20a0 fs/namei.c:3371
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_creat fs/open.c:1262 [inline]
 __se_sys_creat fs/open.c:1256 [inline]
 __x64_sys_creat+0x62/0x80 fs/open.c:1256
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888020597b50 of 8 bytes by task 6966 on cpu 1:
 i_size_read include/linux/fs.h:848 [inline]
 mpage_process_page_bufs+0x34/0x5f0 fs/ext4/inode.c:2193
 mpage_prepare_extent_to_map+0x4e6/0x640 fs/ext4/inode.c:2627
 ext4_writepages+0x97b/0x1e70 fs/ext4/inode.c:2799
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:422
 file_write_and_wait_range+0x9f/0x120 mm/filemap.c:761
 ext4_sync_file+0x105/0x6e0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2737 [inline]
 ext4_buffered_write_iter+0x38f/0x3e0 fs/ext4/file.c:278
 ext4_file_write_iter+0x47a/0x1060 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x41a/0x770 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 fs/splice.c:888
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5e0/0xcf0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6966 Comm: syz-executor.5 Not tainted 5.11.0-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	2021/02/20 12:36	upstream	f40ddce8	3e5ed8b4	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/17 21:56	upstream	f40ddce8	14052202	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/15 23:18	upstream	f40ddce8	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/13 01:50	upstream	dcc0b490	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/12 10:32	upstream	dcc0b490	a5f86b15	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/10 10:56	upstream	e0756cfc	9c8b8541	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/09 01:20	upstream	e0756cfc	2bd9619f	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/08 11:27	upstream	92bf2261	2ce644fc	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/06 23:53	upstream	964d069f	0655e081	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/06 15:05	upstream	1e0d27fc	0655e081	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/05 18:27	upstream	dd86e7fa	23a562df	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/05 04:45	upstream	5c279c4c	23a562df	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/04 15:12	upstream	61556703	42b90a7c	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/02/03 02:31	upstream	3aaf0a27	624dad51	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/31 13:39	upstream	6642d600	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/29 22:36	upstream	bec4c296	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/28 20:35	upstream	e5ff2cb9	7df34f59	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/27 21:03	upstream	76c057c8	a57db36f	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/26 07:45	upstream	f8ad8187	52e37319	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/25 09:45	upstream	6ee1d745	52e37319	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/24 05:05	upstream	e1ae4b0b	52e37319	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/23 09:43	upstream	fe75a218	52e37319	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/23 00:56	upstream	83d09ad4	52e37319	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/22 06:10	upstream	83d09ad4	d4f4eca5	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/21 16:41	upstream	9791581c	d4f4eca5	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/21 03:45	upstream	75439bc4	d4f4eca5	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/18 22:03	upstream	1e2a199f	63631df1	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/18 17:26	upstream	19c329f6	63631df1	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/17 18:52	upstream	0da0a8a0	fd103621	.config	log	report	info	KCSAN: data-race in ext4_setattr / mpage_process_page_bufs
ci2-upstream-kcsan-gce	2021/01/16 19:59	upstream	1d94330a	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 21:34	upstream	65f0d241	a945f0a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 15:41	upstream	e609571b	a945f0a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 08:46	upstream	e609571b	0cdd6185	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/10 03:19	upstream	2ff90100	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/08 14:11	upstream	f5e6c330	c104d4a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/06 04:31	upstream	6207214a	b1c228e1	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/04 23:24	upstream	36bbbd0e	2a28ff1f	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/03 01:34	upstream	3516bd72	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/02 06:25	upstream	eda809ae	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/29 02:58	upstream	c76e02c5	8259d56c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/28 22:09	upstream	c76e02c5	8259d56c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/23 20:08	upstream	614cb589	c2c1d1dd	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/22 03:08	upstream	8653b778	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/20 23:51	upstream	6a447b0e	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/20 02:44	upstream	467f8165	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/18 02:18	upstream	d64c6f96	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/17 04:35	upstream	5e60366d	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/16 09:05	upstream	d01e7f10	649595c6	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/15 05:32	upstream	fab0fca1	97183ed7	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/12 20:50	upstream	7b1b868e	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/20 14:30	upstream	325d0eab	9564d2e9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/18 14:08	upstream	10b82d51	38962c8b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/06/26 02:37	upstream	4a21185c	aea82c00	.config	log	report