KCSAN: data-race in ext4_setattr / ext4

KCSAN: data-race in ext4_setattr / ext4_writepages
Status: auto-closed as invalid on 2020/05/14 14:36
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 564d, last: 564d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_setattr / ext4_writepages (3)	1	233d	233d	0/22	auto-closed as invalid on 2021/03/06 22:57
upstream	KCSAN: data-race in ext4_setattr / ext4_writepages (5)	1	35d	35d	0/22	auto-closed as invalid on 2021/09/20 22:44
upstream	KCSAN: data-race in ext4_setattr / ext4_writepages (2)	1	292d	287d	0/22	auto-closed as invalid on 2021/01/07 02:14
upstream	KCSAN: data-race in ext4_setattr / ext4_writepages (4)	5	105d	184d	0/22	auto-closed as invalid on 2021/07/12 17:41

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_setattr / ext4_writepages

write to 0xffff8880b052f548 of 8 bytes by task 21298 on cpu 0:
 ext4_setattr+0xb2b/0x1290 fs/ext4/inode.c:5330
 notify_change+0x82b/0xb00 fs/attr.c:336
 do_truncate+0xf9/0x180 fs/open.c:64
 do_sys_ftruncate+0x315/0x340 fs/open.c:195
 __do_sys_ftruncate fs/open.c:205 [inline]
 __se_sys_ftruncate fs/open.c:203 [inline]
 __x64_sys_ftruncate+0x3c/0x50 fs/open.c:203
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b052f548 of 8 bytes by task 21294 on cpu 1:
 mpage_map_and_submit_extent fs/ext4/inode.c:2468 [inline]
 ext4_writepages+0x11fd/0x1d40 fs/ext4/inode.c:2772
 do_writepages+0x6b/0x170 mm/page-writeback.c:2344
 __filemap_fdatawrite_range+0x1bb/0x220 mm/filemap.c:421
 file_write_and_wait_range+0xfb/0x160 mm/filemap.c:760
 ext4_sync_file+0x26e/0x8b0 fs/ext4/fsync.c:153
 vfs_fsync_range+0x7c/0x150 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2867 [inline]
 ext4_buffered_write_iter+0x211/0x280 fs/ext4/file.c:277
 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x4a7/0x5d0 fs/read_write.c:693
 do_iter_write fs/read_write.c:998 [inline]
 do_iter_write+0x137/0x3a0 fs/read_write.c:979
 vfs_iter_write+0x56/0x80 fs/read_write.c:1039
 iter_file_splice_write+0x530/0x830 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0x97/0xb0 fs/splice.c:1037
 splice_direct_to_actor+0x22f/0x540 fs/splice.c:992
 do_splice_direct+0x152/0x1d0 fs/splice.c:1080
 do_sendfile+0x396/0x810 fs/read_write.c:1520
 __do_sys_sendfile64 fs/read_write.c:1575 [inline]
 __se_sys_sendfile64 fs/read_write.c:1567 [inline]
 __x64_sys_sendfile64+0xb8/0x140 fs/read_write.c:1567
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 21294 Comm: syz-executor.5 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	2020/03/05 14:31	https://github.com/google/ktsan.git kcsan	766d004d1b85	b655d91b	.config	log	report