KCSAN: data-race in generic_file_buffered_read / generic_write

KCSAN: data-race in generic_file_buffered_read / generic_write_end
Status: moderation: reported on 2020/07/23 18:12
Reported-by: syzbot+f6f4cbb70f468745b776@syzkaller.appspotmail.com
First crash: 256d, last: 30d

Sample crash report:

==================================================================
BUG: KCSAN: data-race in generic_file_buffered_read / generic_write_end

write to 0xffff88810d6afb90 of 8 bytes by task 15828 on cpu 1:
 i_size_write include/linux/fs.h:870 [inline]
 generic_write_end+0x99/0x240 fs/buffer.c:2186
 ext4_da_write_end+0x59b/0x760 fs/ext4/inode.c:3111
 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3419
 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:270
 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:1312 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810d6afb90 of 8 bytes by task 15820 on cpu 0:
 i_size_read include/linux/fs.h:848 [inline]
 generic_file_buffered_read+0x290/0x9c0 mm/filemap.c:2496
 generic_file_read_iter+0x82/0x3e0 mm/filemap.c:2633
 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: 0 PID: 15820 Comm: syz-executor.1 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (170):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/02/04 10:34	upstream	61556703	624dad51	.config	log	report	info	KCSAN: data-race in generic_file_buffered_read / generic_write_end
ci2-upstream-kcsan-gce	2021/02/01 01:11	upstream	1048ba83	fc9fd31e	.config	log	report	info	KCSAN: data-race in generic_file_buffered_read / generic_write_end
ci2-upstream-kcsan-gce	2021/01/10 20:54	upstream	0653161f	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/09 23:12	upstream	2ff90100	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/04 21:06	upstream	36bbbd0e	2a28ff1f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/15 09:54	upstream	148842c9	97183ed7	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/14 20:35	upstream	fab0fca1	97183ed7	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/10 11:10	upstream	a2f5ea9e	2a55c22b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/07 08:45	upstream	0477e928	f80ce148	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/04 18:38	upstream	e87297fa	20366b87	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/02 23:56	upstream	3bb61aa6	8c9190ef	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/29 00:16	upstream	67f34fa8	a0092f9d	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/28 12:38	upstream	c84e1efa	3c7136c0	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/26 23:36	upstream	4df91062	5018c946	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/24 20:48	upstream	80145ac2	e34b696c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/18 18:07	upstream	0fa8ee0d	0767f13f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/17 21:35	upstream	111e91a6	09323409	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/01 18:44	upstream	31f02006	8bc4594f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/31 11:03	upstream	5fc6b075	8bc4594f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/26 23:01	upstream	41ba50b0	8b3eaf58	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/26 09:00	upstream	3650b228	a1839e81	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/25 19:08	upstream	986b9eac	a1839e81	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/24 09:11	upstream	f11901ed	2bb6666c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/22 00:38	upstream	f804b315	be6b1582	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/19 09:03	upstream	7cf726a5	ff4a3345	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/18 17:57	upstream	9453b2d4	fea47c01	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/15 00:03	upstream	3e4fb434	fc7735a2	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/12 08:13	upstream	bbf5c979	4a77ae0b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/11 18:51	upstream	3dd0130f	4a77ae0b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/09 21:47	upstream	8a5f78d9	93817d89	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/08 10:33	upstream	c85fb28b	92390980	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/05 13:26	upstream	549738f1	1880b4a9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/05 00:03	upstream	549738f1	5ef9c291	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/04 09:16	upstream	22fbc037	5ef9c291	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/03 20:40	upstream	22fbc037	1a3f9408	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/02 12:36	upstream	472e5b05	9602ddf4	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/01 08:34	upstream	60e72093	4103fce0	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/30 06:41	upstream	02de58b2	8516f6d3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/28 22:58	upstream	fb0155a0	1b88c6d5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/27 12:48	upstream	a1bffa48	5dd8aee8	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/23 19:01	upstream	805c6d3c	54289b08	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/23 06:15	upstream	805c6d3c	3e8f6c27	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/22 16:44	upstream	eff48dde	3e8f6c27	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/22 08:29	upstream	98477740	3e8f6c27	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/21 21:03	upstream	98477740	9e1fa68e	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/20 13:33	upstream	325d0eab	9564d2e9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/20 10:29	upstream	325d0eab	53ce8104	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/20 03:07	upstream	325d0eab	53ce8104	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/20 00:57	upstream	eb5f95f1	53ce8104	.config	log	report	info
ci2-upstream-kcsan-gce	2020/07/23 15:42	upstream	d15be546	70c104a1	.config	log	report
ci2-upstream-kcsan-gce	2020/06/23 14:31	upstream	dd0d7181	54566aff	.config	log	report