MIME-Version: 1.0
Date:   Thu, 26 Jan 2023 14:27:51 -0800
Message-ID: <00000000000065f83305f3324254@google.com>
Subject: [syzbot] WARNING: locking bug in umh_complete
From:   syzbot <syzbot+6cd18e123583550cf469@syzkaller.appspotmail.com>
To:     linux-kernel@vger.kernel.org, mcgrof@kernel.org,
        netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hello,

syzbot found the following issue on:

HEAD commit:    71ab9c3e2253 net: fix UaF in netns ops registration error ..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=10f86a56480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=899d86a7610a0ea0
dashboard link: https://syzkaller.appspot.com/bug?extid=6cd18e123583550cf469
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/54c953096fdb/disk-71ab9c3e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/644d72265810/vmlinux-71ab9c3e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/16e994579ca5/bzImage-71ab9c3e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6cd18e123583550cf469@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 0 PID: 46 at kernel/locking/lockdep.c:231 hlock_class kernel/locking/lockdep.c:231 [inline]
WARNING: CPU: 0 PID: 46 at kernel/locking/lockdep.c:231 hlock_class kernel/locking/lockdep.c:220 [inline]
WARNING: CPU: 0 PID: 46 at kernel/locking/lockdep.c:231 check_wait_context kernel/locking/lockdep.c:4729 [inline]
WARNING: CPU: 0 PID: 46 at kernel/locking/lockdep.c:231 __lock_acquire+0x13ae/0x56d0 kernel/locking/lockdep.c:5005
Modules linked in:
CPU: 0 PID: 46 Comm: kworker/u4:3 Not tainted 6.2.0-rc4-syzkaller-00191-g71ab9c3e2253 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Workqueue: events_unbound call_usermodehelper_exec_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:231 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:220 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4729 [inline]
RIP: 0010:__lock_acquire+0x13ae/0x56d0 kernel/locking/lockdep.c:5005
Code: 08 84 d2 0f 85 56 41 00 00 8b 15 55 7b 0f 0d 85 d2 0f 85 d5 fd ff ff 48 c7 c6 c0 51 4c 8a 48 c7 c7 20 4b 4c 8a e8 92 e1 5b 08 <0f> 0b 31 ed e9 50 f0 ff ff 48 c7 c0 a8 2b 73 8e 48 ba 00 00 00 00
RSP: 0018:ffffc90000b77a30 EFLAGS: 00010082
RAX: 0000000000000000 RBX: ffff88801272a778 RCX: 0000000000000000
RDX: ffff888012729d40 RSI: ffffffff8166822c RDI: fffff5200016ef38
RBP: 0000000000001b2c R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000001 R11: 0000000000000001 R12: ffff88801272a7c8
R13: ffff888012729d40 R14: ffffc9000397fb28 R15: 0000000000040000
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa5a95e81d0 CR3: 00000000284d2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5668 [inline]
 lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
 complete+0x1d/0x1f0 kernel/sched/completion.c:32
 umh_complete+0x32/0x90 kernel/umh.c:59
 call_usermodehelper_exec_sync kernel/umh.c:144 [inline]
 call_usermodehelper_exec_work+0x115/0x180 kernel/umh.c:167
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>


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