Re: [syzbot] possible deadlock in lapb_disconnect_request

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: MAX_LOCKDEP_CHAINS too low!

BUG: MAX_LOCKDEP_CHAINS too low!
turning off the locking correctness validator.
CPU: 0 PID: 5160 Comm: kworker/u4:6 Not tainted 6.2.0-rc3-syzkaller-00017-g358a161a6a9e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: bond594 bond_netdev_notify_work
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 lookup_chain_cache_add kernel/locking/lockdep.c:3778 [inline]
 validate_chain kernel/locking/lockdep.c:3799 [inline]
 __lock_acquire+0xf2c/0x3084 kernel/locking/lockdep.c:5055
 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x6c/0xb4 kernel/locking/spinlock.c:162
 debug_object_activate+0x6c/0x30c lib/debugobjects.c:665
 debug_timer_activate kernel/time/timer.c:782 [inline]
 __mod_timer+0x534/0x700 kernel/time/timer.c:1119
 add_timer+0x34/0x50 kernel/time/timer.c:1244
 __queue_delayed_work kernel/workqueue.c:1676 [inline]
 queue_delayed_work_on+0x130/0x240 kernel/workqueue.c:1701
 queue_delayed_work include/linux/workqueue.h:518 [inline]
 bond_netdev_notify_work+0xc8/0xf4 drivers/net/bonding/bond_main.c:1743
 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
 worker_thread+0x340/0x610 kernel/workqueue.c:2436
 kthread+0x12c/0x158 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863


Tested on:

commit:         358a161a Merge branch 'for-next/fixes' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=17830e7e480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2573056c6a11f00d
dashboard link: https://syzkaller.appspot.com/bug?extid=c9450e09c6b15886782c
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=161144da480000