syzbot


KCSAN: data-race in iput / writeback_sb_inodes (9)

Status: auto-closed as invalid on 2022/09/08 05:08
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 140d, last: 125d
similar bugs (8):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in iput / writeback_sb_inodes (2) 1 902d 902d 0/24 closed as invalid on 2020/06/18 14:13
upstream KCSAN: data-race in iput / writeback_sb_inodes (3) 1 883d 883d 0/24 auto-closed as invalid on 2020/08/11 19:26
upstream KCSAN: data-race in iput / writeback_sb_inodes (7) 1 469d 469d 0/24 auto-closed as invalid on 2021/09/29 17:35
upstream KCSAN: data-race in iput / writeback_sb_inodes (6) 2 540d 547d 0/24 auto-closed as invalid on 2021/07/20 06:50
upstream KCSAN: data-race in iput / writeback_sb_inodes (8) 1 243d 243d 0/24 auto-closed as invalid on 2022/05/13 10:29
upstream KCSAN: data-race in iput / writeback_sb_inodes 1 1003d 1003d 0/24 auto-closed as invalid on 2020/05/18 05:32
upstream KCSAN: data-race in iput / writeback_sb_inodes (5) 4 678d 702d 0/24 auto-closed as invalid on 2021/03/04 09:19
upstream KCSAN: data-race in iput / writeback_sb_inodes (4) 7 766d 730d 0/24 auto-closed as invalid on 2020/12/21 11:42

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

write to 0xffff88811e1c0ae0 of 8 bytes by task 22494 on cpu 0:
 writeback_sb_inodes+0x494/0xdd0 fs/fs-writeback.c:1854
 __writeback_inodes_wb+0xb0/0x2a0 fs/fs-writeback.c:1936
 wb_writeback+0x280/0x650 fs/fs-writeback.c:2041
 wb_check_start_all fs/fs-writeback.c:2163 [inline]
 wb_do_writeback+0x418/0x600 fs/fs-writeback.c:2189
 wb_workfn+0x88/0x260 fs/fs-writeback.c:2222
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffff88811e1c0ae0 of 8 bytes by task 1822 on cpu 1:
 iput+0x2e/0x580 fs/inode.c:1760
 dentry_unlink_inode+0x22a/0x240 fs/dcache.c:401
 d_delete+0x70/0xa0 fs/dcache.c:2532
 d_delete_notify include/linux/fsnotify.h:259 [inline]
 vfs_rmdir+0x19c/0x2f0 fs/namei.c:4053
 do_rmdir+0x178/0x300 fs/namei.c:4101
 __do_sys_unlinkat fs/namei.c:4281 [inline]
 __se_sys_unlinkat fs/namei.c:4275 [inline]
 __x64_sys_unlinkat+0xa0/0xb0 fs/namei.c:4275
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000020007 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1822 Comm: syz-executor.1 Not tainted 5.19.0-syzkaller-02990-gff89dd08c0f0-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/08/04 05:01 upstream ff89dd08c0f0 1c9013ac .config log report info KCSAN: data-race in iput / writeback_sb_inodes
ci2-upstream-kcsan-gce 2022/07/20 17:40 upstream ca85855bdcae 88cb1383 .config log report info KCSAN: data-race in iput / writeback_sb_inodes
* Struck through repros no longer work on HEAD.