syzbot


WARNING in drop_nlink (2)

Status: upstream: reported C repro on 2020/10/13 17:02
Reported-by: syzbot+651ca866e5e2b4b5095b@syzkaller.appspotmail.com
First crash: 719d, last: 95d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING in sysfs_warn_dup (log)
Repro: C syz .config

Fix bisection: the fix commit could be any of (bisect log):
  583090b1b823 Merge tag 'block5.9-2020-10-08' of git://git.kernel.dk/linux-block
  9e9fb7655ed5 Merge tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 WARNING in drop_nlink C 7 8d05h 182d 0/1 upstream: reported C repro on 2022/03/30 09:01
linux-4.19 WARNING in drop_nlink C error 12 14d 720d 0/1 upstream: reported C repro on 2020/10/08 09:54
upstream WARNING in drop_nlink C done error 1 889d 885d 17/24 fixed on 2020/09/16 22:51
Patch testing requests:
Created Duration User Patch Repo Result
2021/04/22 05:18 12m ducheng2@gmail.com patch linux-next report log
2021/04/22 03:42 11m ducheng2@gmail.com patch upstream report log
2021/04/22 03:17 11m ducheng2@gmail.com patch upstream report log
2021/04/20 03:10 22m ducheng2@gmail.com upstream report log

Sample crash report:
WARNING: CPU: 1 PID: 3684 at fs/inode.c:331 drop_nlink+0xb7/0x110 fs/inode.c:331
Modules linked in:
CPU: 1 PID: 3684 Comm: syz-executor291 Not tainted 5.19.0-rc3-syzkaller-00182-gcbe232ab07ab #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:drop_nlink+0xb7/0x110 fs/inode.c:331
Code: 28 be 08 00 00 00 48 8d bb c0 07 00 00 e8 01 a3 ea ff f0 48 ff 83 c0 07 00 00 5b 5d 41 5c 41 5d e9 7e 7c 9e ff e8 79 7c 9e ff <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 0f b6 04
RSP: 0018:ffffc90002e67ad0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888028bed040 RCX: 0000000000000000
RDX: ffff888024404000 RSI: ffffffff81db1b57 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 00000000ffffffff
R13: ffff888028bed088 R14: ffff888028bed040 R15: ffff888028befae0
FS:  0000555555f70300(0000) GS:ffff88802c900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200017c0 CR3: 000000001ea3e000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 inode_dec_link_count include/linux/fs.h:2368 [inline]
 minix_rename+0x24e/0x4c0 fs/minix/namei.c:230
 vfs_rename+0xef2/0x17a0 fs/namei.c:4719
 do_renameat2+0xb5e/0xc80 fs/namei.c:4870
 __do_sys_renameat fs/namei.c:4910 [inline]
 __se_sys_renameat fs/namei.c:4907 [inline]
 __x64_sys_renameat+0xbf/0xf0 fs/namei.c:4907
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7ff49e648429
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdcfba35f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000108
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007ff49e648429
RDX: 0000000000000009 RSI: 0000000020000500 RDI: 000000000000000a
RBP: 00007ff49e607a30 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000200017c0 R11: 0000000000000246 R12: 00007ff49e607ac0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-qemu-upstream 2022/06/25 07:11 upstream cbe232ab07ab a371c43c .config log report syz C WARNING in drop_nlink
ci-upstream-kasan-gce-smack-root 2020/10/09 16:56 upstream 583090b1b823 d81b165e .config log report syz C
* Struck through repros no longer work on HEAD.