KCSAN: data-race in ext4_mpage_readpages / ext4

KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (2)
Status: auto-closed as invalid on 2021/03/15 11:12
Reported-by: syzbot+1c07301bb00f6574534a@syzkaller.appspotmail.com
First crash: 391d, last: 167d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_mpage_readpages / ext4_setattr				3	509d	585d	0/22	auto-closed as invalid on 2020/05/12 04:51
upstream	KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (3)				8	60d	108d	0/22	auto-closed as invalid on 2021/06/30 12:56

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_mpage_readpages / ext4_setattr

write to 0xffff8881101b8190 of 8 bytes by task 11362 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 fs/open.c:64 [inline]
 do_sys_ftruncate+0x42d/0x530 fs/open.c:195
 __do_sys_ftruncate fs/open.c:205 [inline]
 __se_sys_ftruncate fs/open.c:203 [inline]
 __x64_sys_ftruncate+0x2f/0x40 fs/open.c:203
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881101b8190 of 8 bytes by task 11357 on cpu 1:
 ext4_readpage_limit fs/ext4/readpage.c:219 [inline]
 ext4_mpage_readpages+0x4f9/0x15c0 fs/ext4/readpage.c:265
 ext4_readahead+0x99/0xa0 fs/ext4/inode.c:3261
 read_pages+0x9c/0x6e0 mm/readahead.c:130
 page_cache_ra_unbounded+0x46c/0x4c0 mm/readahead.c:238
 ondemand_readahead+0x560/0x780 mm/readahead.c:267
 page_cache_sync_ra+0x18f/0x1a0 mm/readahead.c:577
 page_cache_sync_readahead include/linux/pagemap.h:839 [inline]
 generic_file_buffered_read_get_pages+0x234/0xaf0 mm/filemap.c:2365
 generic_file_buffered_read+0x26e/0x9c0 mm/filemap.c:2485
 generic_file_read_iter+0x82/0x3e0 mm/filemap.c:2637
 ext4_file_read_iter+0x2e0/0x430 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1895 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:788 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867
 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: 11357 Comm: syz-executor.3 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (15):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/02/08 11:11	upstream	92bf22614b21	2ce644fc	.config	log	report	info	KCSAN: data-race in ext4_mpage_readpages / ext4_setattr
ci2-upstream-kcsan-gce	2021/01/30 18:40	upstream	0e9bcda5d286	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_mpage_readpages / ext4_setattr
ci2-upstream-kcsan-gce	2021/01/08 06:55	upstream	f5e6c330254a	c104d4a3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/31 16:34	upstream	f6e1ea196492	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/01 12:24	upstream	b65054597872	07bfe8a5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/19 21:41	upstream	131ad0b6f529	0767f13f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/16 11:58	upstream	09162bc32c88	1bf9a662	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/25 19:22	upstream	986b9eacb259	a1839e81	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/28 02:58	upstream	a1b8638ba132	5dd8aee8	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/23 22:40	upstream	c9c9e6a49f89	54289b08	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/18 12:58	upstream	10b82d517648	38962c8b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/08/25 22:56	upstream	abb3438d69fb	344da168	.config	log	report
ci2-upstream-kcsan-gce	2020/08/04 08:09	upstream	e4cbce4d1317	96dd3623	.config	log	report
ci2-upstream-kcsan-gce	2020/07/08 07:55	upstream	dcde237b9b0e	5962a2dc	.config	log	report
ci2-upstream-kcsan-gce	2020/06/29 16:26	upstream	9ebcfadb0610	ce9ef6f2	.config	log	report