KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping

KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers (4)
Status: auto-closed as invalid on 2021/01/23 11:44
Reported-by: syzbot+2ac2c251e7a08d2dc8ac@syzkaller.appspotmail.com
First crash: 80d, last: 36d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers	8	361d	430d	0/17	auto-closed as invalid on 2020/04/08 22:27
upstream	KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers (3)	10	122d	214d	0/17	auto-closed as invalid on 2020/10/29 18:32
upstream	KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers (2)	1	251d	251d	0/17	closed as invalid on 2020/06/18 14:13

Sample crash report:

==================================================================
BUG: KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers

write to 0xffff88810d98c948 of 8 bytes by task 14812 on cpu 0:
 __remove_assoc_queue fs/buffer.c:481 [inline]
 fsync_buffers_list fs/buffer.c:713 [inline]
 sync_mapping_buffers+0x155/0x7d0 fs/buffer.c:548
 ext4_fsync_nojournal fs/ext4/fsync.c:86 [inline]
 ext4_sync_file+0x286/0x6c0 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2737 [inline]
 ext4_buffered_write_iter+0x384/0x3d0 fs/ext4/file.c:278
 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4b0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x42a/0x780 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+0x5db/0xca0 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

read to 0xffff88810d98c948 of 8 bytes by task 14804 on cpu 1:
 mark_buffer_dirty_inode+0x92/0x1b0 fs/buffer.c:581
 __ext4_handle_dirty_metadata+0x1af/0x590 fs/ext4/ext4_jbd2.c:360
 __ext4_ext_dirty fs/ext4/extents.c:165 [inline]
 ext4_ext_insert_extent+0x1c75/0x2b50 fs/ext4/extents.c:2130
 ext4_ext_map_blocks+0x16a3/0x1fc0 fs/ext4/extents.c:4259
 ext4_map_blocks+0x700/0xfc0 fs/ext4/inode.c:628
 ext4_iomap_alloc fs/ext4/inode.c:3418 [inline]
 ext4_iomap_begin+0x503/0x690 fs/ext4/inode.c:3468
 iomap_apply+0x8d/0x4a0 fs/iomap/apply.c:46
 __iomap_dio_rw+0x448/0x9b0 fs/iomap/direct-io.c:517
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:605
 ext4_dio_write_iter fs/ext4/file.c:552 [inline]
 ext4_file_write_iter+0xe06/0x1090 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+0x112/0x4b0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x42a/0x780 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+0x5db/0xca0 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14804 Comm: syz-executor.3 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (5):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Maintainers
ci2-upstream-kcsan-gce	2020/12/19 11:44	upstream	3644e2d2	04201c06	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci2-upstream-kcsan-gce	2020/12/08 09:45	upstream	cd796ed3	9af51e31	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci2-upstream-kcsan-gce	2020/12/07 22:43	upstream	cd796ed3	51a9082e	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci2-upstream-kcsan-gce	2020/12/01 10:01	upstream	b6505459	b3a34598	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci2-upstream-kcsan-gce	2020/11/05 18:31	upstream	4ef8451b	cba33199	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk