KCSAN: data-race in ext4_file_write_iter / ext4

KCSAN: data-race in ext4_file_write_iter / ext4_setattr (4)
Status: auto-closed as invalid on 2021/06/18 10:04
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 129d, last: 129d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_file_write_iter / ext4_setattr (2)	1	287d	287d	0/22	auto-closed as invalid on 2021/01/11 11:39
upstream	KCSAN: data-race in ext4_file_write_iter / ext4_setattr (3)	2	165d	166d	0/22	auto-closed as invalid on 2021/05/14 00:08
upstream	KCSAN: data-race in ext4_file_write_iter / ext4_setattr	3	356d	380d	0/22	auto-closed as invalid on 2020/11/03 10:53
upstream	KCSAN: data-race in ext4_file_write_iter / ext4_setattr (5)	3	38d	74d	0/22	auto-closed as invalid on 2021/09/18 07:46

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_file_write_iter / ext4_setattr

write to 0xffff88813490fb70 of 8 bytes by task 3771 on cpu 0:
 i_size_write include/linux/fs.h:871 [inline]
 ext4_setattr+0xd54/0xec0 fs/ext4/inode.c:5481
 notify_change+0x8a3/0xa80 fs/attr.c:398
 do_truncate+0xe8/0x130 fs/open.c:64
 handle_truncate fs/namei.c:3017 [inline]
 do_open fs/namei.c:3365 [inline]
 path_openat+0x1a79/0x20b0 fs/namei.c:3494
 do_filp_open+0xd9/0x1f0 fs/namei.c:3521
 do_sys_openat2+0xa3/0x250 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1214
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813490fb70 of 8 bytes by task 3716 on cpu 1:
 i_size_read include/linux/fs.h:849 [inline]
 ext4_dio_write_iter fs/ext4/file.c:495 [inline]
 ext4_file_write_iter+0x14c/0x11d0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [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+0x40a/0x750 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1319 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3716 Comm: syz-executor.4 Tainted: G        W         5.13.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/05/14 09:58	upstream	315d99318179	8bdd5343	.config	log	report			info	KCSAN: data-race in ext4_file_write_iter / ext4_setattr