syzbot


KCSAN: data-race in iput / move_expired_inodes (4)

Status: auto-closed as invalid on 2021/10/15 01:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 442d, last: 442d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in iput / move_expired_inodes (5) 1 163d 163d 0/24 auto-closed as invalid on 2022/07/21 10:59
upstream KCSAN: data-race in iput / move_expired_inodes 5 733d 719d 0/24 auto-closed as invalid on 2020/12/27 22:09
upstream KCSAN: data-race in iput / move_expired_inodes (3) 3 571d 616d 0/24 auto-closed as invalid on 2021/06/07 20:37
upstream KCSAN: data-race in iput / move_expired_inodes (2) 1 682d 682d 0/24 auto-closed as invalid on 2021/02/16 20:27

Sample crash report:
==================================================================
BUG: KCSAN: data-race in iput / move_expired_inodes

write to 0xffff888127e503f0 of 8 bytes by task 6678 on cpu 0:
 move_expired_inodes+0x1ca/0x4c0 fs/fs-writeback.c:1406
 queue_io+0xe1/0x270 fs/fs-writeback.c:1453
 wb_writeback+0x255/0x6d0 fs/fs-writeback.c:2051
 wb_do_writeback+0x101/0x530 fs/fs-writeback.c:2196
 wb_workfn+0xc8/0x540 fs/fs-writeback.c:2237
 process_one_work+0x402/0x910 kernel/workqueue.c:2297
 worker_thread+0x636/0xae0 kernel/workqueue.c:2444
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

read to 0xffff888127e503f0 of 8 bytes by task 1133 on cpu 1:
 iput+0x2e/0x580 fs/inode.c:1678
 dentry_unlink_inode+0x273/0x290 fs/dcache.c:376
 d_delete+0x78/0xe0 fs/dcache.c:2505
 vfs_rmdir+0x2e6/0x300 fs/namei.c:3984
 do_rmdir+0x18d/0x340 fs/namei.c:4032
 __do_sys_rmdir fs/namei.c:4051 [inline]
 __se_sys_rmdir fs/namei.c:4049 [inline]
 __x64_sys_rmdir+0x2c/0x30 fs/namei.c:4049
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000001 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1133 Comm: syz-executor.2 Not tainted 5.14.0-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 2021/09/10 01:34 upstream bf9f243f23e6 e2776ee4 .config log report info KCSAN: data-race in iput / move_expired_inodes
* Struck through repros no longer work on HEAD.