KCSAN: data-race in ext4_file_write_iter / ext4_handle_inode

KCSAN: data-race in ext4_file_write_iter / ext4_handle_inode_extension
Status: auto-closed as invalid on 2020/05/04 10:14
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 581d, last: 581d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_file_write_iter / ext4_handle_inode_extension (2)				2	409d	412d	0/22	auto-closed as invalid on 2020/09/18 14:01

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_file_write_iter / ext4_handle_inode_extension

write to 0xffff8881250e3438 of 8 bytes by task 17737 on cpu 0:
 i_size_write include/linux/fs.h:888 [inline]
 ext4_update_inode_size fs/ext4/ext4.h:3042 [inline]
 ext4_handle_inode_extension+0x3d3/0x5b0 fs/ext4/file.c:330
 ext4_dio_write_iter fs/ext4/file.c:536 [inline]
 ext4_file_write_iter+0x849/0xd70 fs/ext4/file.c:640
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:998 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:979
 vfs_iter_write+0x5c/0x80 fs/read_write.c:1039
 iter_file_splice_write+0x536/0x850 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
 do_splice_direct+0x161/0x1e0 fs/splice.c:1080
 do_sendfile+0x384/0x7f0 fs/read_write.c:1520
 __do_sys_sendfile64 fs/read_write.c:1581 [inline]
 __se_sys_sendfile64 fs/read_write.c:1567 [inline]
 __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1567
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881250e3438 of 8 bytes by task 17741 on cpu 1:
 ext4_dio_write_iter fs/ext4/file.c:467 [inline]
 ext4_file_write_iter+0x1fa/0xd70 fs/ext4/file.c:640
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:998 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:979
 vfs_iter_write+0x5c/0x80 fs/read_write.c:1039
 iter_file_splice_write+0x536/0x850 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
 do_splice_direct+0x161/0x1e0 fs/splice.c:1080
 do_sendfile+0x384/0x7f0 fs/read_write.c:1520
 __do_sys_sendfile64 fs/read_write.c:1581 [inline]
 __se_sys_sendfile64 fs/read_write.c:1567 [inline]
 __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1567
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17741 Comm: syz-executor.0 Not tainted 5.6.0-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	2020/02/24 10:08	https://github.com/google/ktsan.git kcsan	766d004d1b85	1253d6f0	.config	log	report