syzbot


KCSAN: data-race in __writeback_single_inode / iput (6)

Status: auto-obsoleted due to no activity on 2023/12/24 00:08
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+32f6c22cbfc7a3d98f1e@syzkaller.appspotmail.com
First crash: 182d, last: 121d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __writeback_single_inode / iput (2) fs 2 1400d 1456d 0/26 auto-closed as invalid on 2020/06/18 13:23
upstream KCSAN: data-race in __writeback_single_inode / iput (3) fs 1 980d 980d 0/26 auto-closed as invalid on 2021/07/31 05:30
upstream KCSAN: data-race in __writeback_single_inode / iput fs 1 1537d 1537d 0/26 auto-closed as invalid on 2020/02/25 20:08
upstream KCSAN: data-race in __writeback_single_inode / iput (5) fs 2 538d 546d 0/26 auto-obsoleted due to no activity on 2022/10/16 04:00
upstream KCSAN: data-race in __writeback_single_inode / iput (4) fs 1 886d 886d 0/26 auto-closed as invalid on 2021/11/02 09:27

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

read-write to 0xffff8881005b0438 of 8 bytes by task 22711 on cpu 1:
 __writeback_single_inode+0x201/0x860 fs/fs-writeback.c:1661
 writeback_sb_inodes+0x514/0xad0 fs/fs-writeback.c:1916
 __writeback_inodes_wb+0x9a/0x1a0 fs/fs-writeback.c:1987
 wb_writeback+0x264/0x6e0 fs/fs-writeback.c:2094
 wb_check_background_flush fs/fs-writeback.c:2164 [inline]
 wb_do_writeback fs/fs-writeback.c:2252 [inline]
 wb_workfn+0x67f/0x8d0 fs/fs-writeback.c:2279
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
 worker_thread+0x525/0x730 kernel/workqueue.c:2784
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

read to 0xffff8881005b0438 of 8 bytes by task 23282 on cpu 0:
 iput+0x32/0x5b0 fs/inode.c:1791
 blkdev_get_no_open+0xaf/0xe0 block/bdev.c:722
 blkdev_get_by_dev+0x64/0x390 block/bdev.c:767
 bdev_open_by_dev+0x56/0xd0 block/bdev.c:840
 blkdev_open+0xfb/0x200 block/fops.c:600
 do_dentry_open+0x635/0xbd0 fs/open.c:948
 vfs_open+0x4a/0x50 fs/open.c:1082
 do_open fs/namei.c:3622 [inline]
 path_openat+0x1819/0x1d70 fs/namei.c:3779
 do_filp_open+0xf6/0x200 fs/namei.c:3809
 do_sys_openat2+0xab/0x110 fs/open.c:1440
 do_sys_open fs/open.c:1455 [inline]
 __do_sys_openat fs/open.c:1471 [inline]
 __se_sys_openat fs/open.c:1466 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1466
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000020084 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 23282 Comm: udevd Tainted: G        W          6.6.0-syzkaller-10396-g4652b8e4f3ff #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/02 20:43 upstream 4652b8e4f3ff c4ac074c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __writeback_single_inode / iput
2023/09/30 23:05 upstream 3b517966c561 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __writeback_single_inode / iput
2023/09/02 22:30 upstream 0468be89b3fa 696ea0d2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __writeback_single_inode / iput
* Struck through repros no longer work on HEAD.