KCSAN: data-race in evict / writeback_sb

KCSAN: data-race in evict / writeback_sb_inodes (4)
Status: auto-closed as invalid on 2021/06/29 12:32
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 118d, last: 118d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in evict / writeback_sb_inodes (2)	1	271d	271d	0/22	auto-closed as invalid on 2021/01/27 13:06
upstream	KCSAN: data-race in evict / writeback_sb_inodes (3)	1	191d	191d	0/22	auto-closed as invalid on 2021/04/17 10:46
upstream	KCSAN: data-race in evict / writeback_sb_inodes	3	358d	386d	0/22	auto-closed as invalid on 2020/11/01 12:53

Sample crash report:

BUG: KCSAN: data-race in evict / writeback_sb_inodes

write to 0xffff888106a50358 of 8 bytes by task 22 on cpu 1:
 redirty_tail_locked fs/fs-writeback.c:1190 [inline]
 writeback_sb_inodes+0x2f5/0xf10 fs/fs-writeback.c:1688
 wb_writeback+0x28e/0x700 fs/fs-writeback.c:1905
 wb_do_writeback+0x101/0x510 fs/fs-writeback.c:2050
 wb_workfn+0xc8/0x520 fs/fs-writeback.c:2091
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x1d0/0x1f0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888106a50358 of 8 bytes by task 1782 on cpu 0:
 evict+0x42/0x3c0 fs/inode.c:567
 iput_final fs/inode.c:1660 [inline]
 iput+0x433/0x590 fs/inode.c:1686
 dentry_unlink_inode+0x23a/0x260 fs/dcache.c:376
 d_delete+0x78/0xe0 fs/dcache.c:2505
 vfs_rmdir+0x2a6/0x2c0 fs/namei.c:3909
 do_rmdir+0x14a/0x2e0 fs/namei.c:3958
 __do_sys_rmdir fs/namei.c:3976 [inline]
 __se_sys_rmdir fs/namei.c:3974 [inline]
 __x64_sys_rmdir+0x2c/0x30 fs/namei.c:3974
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1782 Comm: syz-executor.2 Not tainted 5.13.0-rc3-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	2021/05/25 12:26	upstream	1434a3127887	3c7fef33	.config	log	report			info	KCSAN: data-race in evict / writeback_sb_inodes