KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup

KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent (2)
Status: auto-closed as invalid on 2020/06/18 13:13
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 513d, last: 513d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent (4)	1	241d	241d	0/22	auto-closed as invalid on 2021/02/22 02:14
upstream	KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent (3)	2	361d	370d	0/22	auto-closed as invalid on 2020/10/24 21:16
upstream	KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent	1	601d	601d	0/22	auto-closed as invalid on 2020/04/03 02:12

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent

write to 0xffff88811d19a598 of 8 bytes by task 24499 on cpu 1:
 ext4_es_set_referenced fs/ext4/extents_status.h:194 [inline]
 ext4_es_lookup_extent+0x3f1/0x570 fs/ext4/extents_status.c:950
 ext4_map_blocks+0xba/0xcf0 fs/ext4/inode.c:511
 mpage_map_one_extent fs/ext4/inode.c:2364 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2417 [inline]
 ext4_writepages+0x10c4/0x1e10 fs/ext4/inode.c:2770
 do_writepages+0x6b/0x170 mm/page-writeback.c:2344
 __filemap_fdatawrite_range+0x1bb/0x220 mm/filemap.c:421
 __filemap_fdatawrite mm/filemap.c:429 [inline]
 filemap_flush+0x2a/0x40 mm/filemap.c:456
 ext4_alloc_da_blocks+0x72/0x170 fs/ext4/inode.c:3144
 ext4_release_file+0x107/0x200 fs/ext4/file.c:142
 __fput+0x1e9/0x500 fs/file_table.c:280
 ____fput+0x1b/0x30 fs/file_table.c:313
 task_work_run+0xba/0x120 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2ae/0x2c0 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x38b/0x3b0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811d19a598 of 8 bytes by task 24501 on cpu 0:
 ext4_es_is_delayed+0x1c/0x40 fs/ext4/extents_status.h:174
 __es_find_extent_range+0x183/0x270 fs/ext4/extents_status.c:297
 ext4_es_find_extent_range+0x6e/0x260 fs/ext4/extents_status.c:317
 ext4_ext_put_gap_in_cache+0x4a/0xf0 fs/ext4/extents.c:2227
 ext4_ext_map_blocks+0x1071/0x1fb0 fs/ext4/extents.c:4122
 ext4_da_map_blocks fs/ext4/inode.c:1733 [inline]
 ext4_da_get_block_prep+0x758/0xa50 fs/ext4/inode.c:1810
 ext4_block_write_begin+0x336/0xbd0 fs/ext4/inode.c:1053
 ext4_da_write_begin+0x220/0x860 fs/ext4/inode.c:2995
 generic_perform_write+0x13a/0x320 mm/filemap.c:3302
 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270
 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write+0x303/0x400 fs/read_write.c:484
 __vfs_write+0x9e/0xb0 fs/read_write.c:497
 vfs_write fs/read_write.c:559 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:543
 ksys_write+0xc5/0x1a0 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write fs/read_write.c:621 [inline]
 __x64_sys_write+0x49/0x60 fs/read_write.c:621
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 24501 Comm: syz-executor.2 Not tainted 5.7.0-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	2020/04/20 19:02	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	347a5dc3	.config	log	report