KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered

KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
Status: moderation: reported on 2020/11/12 15:07
Reported-by: syzbot+745a40728c2f32a454b6@syzkaller.appspotmail.com
First crash: 255d, last: 14d

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read

write to 0xffff8880121f6290 of 8 bytes by task 10742 on cpu 0:
 i_size_write include/linux/fs.h:870 [inline]
 ext4_update_inode_size fs/ext4/ext4.h:3285 [inline]
 ext4_handle_inode_extension+0x226/0x550 fs/ext4/file.c:332
 ext4_dio_write_iter fs/ext4/file.c:558 [inline]
 ext4_file_write_iter+0xeaa/0x1060 fs/ext4/file.c:662
 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

read to 0xffff8880121f6290 of 8 bytes by task 10736 on cpu 1:
 i_size_read include/linux/fs.h:848 [inline]
 generic_file_buffered_read+0x290/0x9c0 mm/filemap.c:2500
 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: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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10736 Comm: syz-executor.1 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (120):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/02/21 09:57	upstream	e767b353	3e5ed8b4	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/20 16:30	upstream	f40ddce8	3e5ed8b4	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/15 06:04	upstream	f40ddce8	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/15 00:48	upstream	358fecee	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/13 00:39	upstream	dcc0b490	98682e5e	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/12 12:14	upstream	dcc0b490	a5f86b15	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/11 19:09	upstream	291009f6	a5f86b15	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/08 03:01	upstream	b75dba7f	2ce644fc	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/07 10:14	upstream	825b5991	2ce644fc	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/07 04:52	upstream	964d069f	0655e081	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/06 03:32	upstream	1e0d27fc	23a562df	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/05 03:48	upstream	5c279c4c	23a562df	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/04 17:45	upstream	61556703	42b90a7c	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/03 11:46	upstream	3aaf0a27	624dad51	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/02 10:29	upstream	88bb507a	19e09687	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/02/01 21:15	upstream	88bb507a	e6b95f32	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/01/31 12:46	upstream	6642d600	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/01/29 05:01	upstream	e5ff2cb9	7df34f59	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/01/27 19:49	upstream	76c057c8	a57db36f	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/01/26 14:51	upstream	13391c60	52e37319	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/01/24 21:54	upstream	e6806137	52e37319	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/01/18 22:09	upstream	1e2a199f	63631df1	.config	log	report	info	KCSAN: data-race in ext4_handle_inode_extension / generic_file_buffered_read
ci2-upstream-kcsan-gce	2021/01/16 23:23	upstream	54c6247d	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/12 00:59	upstream	a0d54b4f	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/08 21:37	upstream	6279d812	c104d4a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/07 04:23	upstream	71c061d2	c104d4a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/06 12:28	upstream	9f1abbe9	fff20c29	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/04 05:23	upstream	e71ba945	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/03 03:32	upstream	3516bd72	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/02 02:49	upstream	eda809ae	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/31 14:43	upstream	f6e1ea19	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/29 15:57	upstream	dea8dcf2	80910769	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/29 02:25	upstream	c76e02c5	8259d56c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/28 04:50	upstream	5c8fe583	2242f77f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/26 14:04	upstream	40f78232	821e0b09	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/25 11:06	upstream	71c5f031	b982b3ea	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/24 01:06	upstream	58cf05f5	c2c1d1dd	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/21 09:58	upstream	e37b12e4	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/15 22:10	upstream	d635a69d	f213e07e	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/14 09:21	upstream	2c85ebc5	b22a7ec3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/13 23:39	upstream	ec6f5e0e	8f160dd5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/13 10:32	upstream	6bff9bb8	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/12 21:33	upstream	7b1b868e	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/12 00:11	upstream	7f376f19	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/11 14:15	upstream	33dc9614	ba24ffcd	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/11 03:57	upstream	9fca90cf	f900b48c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/10 11:16	upstream	a2f5ea9e	2a55c22b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/09 21:47	upstream	ca4bbdaf	c090b4da	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/09 09:41	upstream	a68a0262	99917735	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/08 11:18	upstream	cd796ed3	9af51e31	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/06 09:28	upstream	7059c2c0	f12ba0c5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/05 22:37	upstream	32f741b0	50503117	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/10 08:26	upstream	407ab579	cca87986	.config	log	report	info
ci2-upstream-kcsan-gce	2020/06/25 20:28	upstream	908f7d12	adb7d9e6	.config	log	report