KCSAN: data-race in ondemand_readahead / ondemand

KCSAN: data-race in ondemand_readahead / ondemand_readahead (2)
Status: moderation: reported on 2020/08/21 00:58
Reported-by: syzbot+75c8f278444ac898e162@syzkaller.appspotmail.com
First crash: 96d, last: 2h00m

similar bugs (1):
Kernel	Title	Repro	Bisected	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ondemand_readahead / ondemand_readahead			44	103d	316d	0/17	closed as invalid on 2020/06/18 14:24

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ondemand_readahead / ondemand_readahead

write to 0xffff88811f895f98 of 8 bytes by task 26541 on cpu 1:
 ondemand_readahead+0x1f9/0x6e0 mm/readahead.c:529
 page_cache_sync_readahead+0x178/0x1a0 mm/readahead.c:585
 generic_file_buffered_read+0x2ec/0x1f60 mm/filemap.c:2199
 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2503
 ext4_file_read_iter+0x2d8/0x420 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1876 [inline]
 generic_file_splice_read+0x22b/0x310 fs/splice.c:312
 do_splice_to fs/splice.c:870 [inline]
 splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x56a/0xba0 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811f895f98 of 8 bytes by task 26542 on cpu 0:
 ondemand_readahead+0x122/0x6e0 mm/readahead.c:467
 page_cache_sync_readahead+0x178/0x1a0 mm/readahead.c:585
 generic_file_buffered_read+0x2ec/0x1f60 mm/filemap.c:2199
 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2503
 ext4_file_read_iter+0x2d8/0x420 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1876 [inline]
 generic_file_splice_read+0x22b/0x310 fs/splice.c:312
 do_splice_to fs/splice.c:870 [inline]
 splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x56a/0xba0 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 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: 0 PID: 26542 Comm: syz-executor.3 Not tainted 5.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (122):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Maintainers
ci2-upstream-kcsan-gce	2020/09/29 03:46	upstream	fb0155a0	1b88c6d5	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/26 20:19	upstream	eeddbe68	2d5ea0cb	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/26 09:18	upstream	7c7ec322	4a006f63	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/25 16:02	upstream	171d4ff7	4a006f63	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/24 18:50	upstream	171d4ff7	54289b08	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/24 01:23	upstream	c9c9e6a4	54289b08	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/23 21:15	upstream	805c6d3c	54289b08	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/23 09:44	upstream	805c6d3c	287cd75a	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/22 18:00	upstream	eff48dde	3e8f6c27	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/21 23:30	upstream	98477740	9e1fa68e	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/20 22:56	upstream	bdcf11de	9564d2e9	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/20 15:47	upstream	325d0eab	9564d2e9	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/20 09:32	upstream	325d0eab	53ce8104	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/20 00:27	upstream	eb5f95f1	53ce8104	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/19 22:20	upstream	eb5f95f1	53ce8104	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/19 20:36	upstream	eb5f95f1	53ce8104	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/19 18:39	upstream	eb5f95f1	53ce8104	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/19 04:48	upstream	92ab97ad	53ce8104	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/18 23:05	upstream	92ab97ad	53ce8104	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/18 13:37	upstream	10b82d51	38962c8b	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/18 11:42	upstream	10b82d51	38962c8b	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/18 07:00	upstream	4cbffc46	8247808b	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/18 03:07	upstream	4cbffc46	8247808b	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/17 16:41	upstream	5925fa68	8247808b	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/17 12:33	upstream	5925fa68	8247808b	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/17 07:35	upstream	5925fa68	8247808b	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/16 23:59	upstream	5925fa68	77507d02	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/16 14:44	upstream	fc4f28bb	77507d02	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/16 12:45	upstream	fc4f28bb	18d7d030	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/16 06:57	upstream	fc4f28bb	18d7d030	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/15 16:04	upstream	fc4f28bb	9e681632	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/15 09:22	upstream	fc4f28bb	9e681632	.config	log	report	info	akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/12 16:20	upstream	729e3d09	21d289c2	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/11 23:20	upstream	e8878ab8	79fb24e2	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/11 12:39	upstream	581cb3a2	adfb8b4e	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/10 11:05	upstream	7fe10096	ac7ca78e	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/09 20:04	upstream	34d4ddd3	ac7ca78e	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/09 09:28	upstream	34d4ddd3	0ea7a887	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/08 21:17	upstream	6f6a73c8	abf9ba4f	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/08 21:08	upstream	6f6a73c8	abf9ba4f	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/07 16:17	upstream	f4d51dff	abf9ba4f	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/09/07 06:06	upstream	a8205e31	abf9ba4f	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/08/20 06:11	upstream	7eac66d0	ed282a3a	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/08/20 02:10	upstream	18445bf4	ed282a3a	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci2-upstream-kcsan-gce	2020/06/25 04:50	upstream	26e122e9	9d60b18e	.config	log	report		akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org