KCSAN: data-race in __writeback_single_inode / vfs_fsync

KCSAN: data-race in __writeback_single_inode / vfs_fsync_range
Status: closed as invalid on 2019/11/19 14:44
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 683d, last: 681d

similar bugs (5):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __writeback_single_inode / vfs_fsync_range (6)	1	147d	147d	0/22	auto-closed as invalid on 2021/06/01 07:24
upstream	KCSAN: data-race in __writeback_single_inode / vfs_fsync_range (5)	2	224d	240d	0/22	auto-closed as invalid on 2021/03/15 14:17
upstream	KCSAN: data-race in __writeback_single_inode / vfs_fsync_range (3)	2	419d	446d	0/22	auto-closed as invalid on 2020/09/02 05:07
upstream	KCSAN: data-race in __writeback_single_inode / vfs_fsync_range (2)	2	657d	658d	0/22	auto-closed as invalid on 2020/02/12 06:26
upstream	KCSAN: data-race in __writeback_single_inode / vfs_fsync_range (4)	1	379d	379d	0/22	auto-closed as invalid on 2020/10/12 03:20

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __writeback_single_inode / vfs_fsync_range

write to 0xffff88812580e6b0 of 8 bytes by task 3654 on cpu 1:
 __writeback_single_inode+0x328/0x8e0 fs/fs-writeback.c:1483
 writeback_single_inode+0x232/0x310 fs/fs-writeback.c:1562
 sync_inode fs/fs-writeback.c:2599 [inline]
 sync_inode_metadata+0x74/0xa0 fs/fs-writeback.c:2619
 __generic_file_fsync+0x122/0x190 fs/libfs.c:1011
 ext4_sync_file+0x48e/0xb00 fs/ext4/fsync.c:120
 vfs_fsync_range+0x82/0x150 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2853 [inline]
 ext4_file_write_iter+0x45b/0xa00 fs/ext4/file.c:279
 call_write_iter include/linux/fs.h:1895 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:951
 vfs_iter_write+0x5c/0x80 fs/read_write.c:983
 iter_file_splice_write+0x4c0/0x7f0 fs/splice.c:746
 do_splice_from fs/splice.c:848 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1020
 splice_direct_to_actor+0x215/0x510 fs/splice.c:975
 do_splice_direct+0x161/0x1e0 fs/splice.c:1063
 do_sendfile+0x384/0x7f0 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1511
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812580e6b0 of 8 bytes by task 3658 on cpu 0:
 vfs_fsync_range+0xdb/0x150 fs/sync.c:195
 generic_write_sync include/linux/fs.h:2853 [inline]
 ext4_file_write_iter+0x45b/0xa00 fs/ext4/file.c:279
 call_write_iter include/linux/fs.h:1895 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:951
 vfs_iter_write+0x5c/0x80 fs/read_write.c:983
 iter_file_splice_write+0x4c0/0x7f0 fs/splice.c:746
 do_splice_from fs/splice.c:848 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1020
 splice_direct_to_actor+0x215/0x510 fs/splice.c:975
 do_splice_direct+0x161/0x1e0 fs/splice.c:1063
 do_sendfile+0x384/0x7f0 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1511
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3658 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2019/11/09 21:18	https://github.com/google/ktsan.git kcsan	94c006602e13	1e35461e	.config	log	report
ci2-upstream-kcsan-gce	2019/11/08 04:26	https://github.com/google/ktsan.git kcsan	94c006602e13	f39aff9e	.config	log	report