[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.45' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 29.569922] [ 29.571549] ====================================================== [ 29.577890] WARNING: possible circular locking dependency detected [ 29.584180] 4.14.289-syzkaller #0 Not tainted [ 29.588659] ------------------------------------------------------ [ 29.594959] syz-executor205/7967 is trying to acquire lock: [ 29.600645] ((&strp->work)){+.+.}, at: [] flush_work+0x88/0x770 [ 29.608339] [ 29.608339] but task is already holding lock: [ 29.614309] (sk_lock-AF_INET){+.+.}, at: [] kcm_ioctl+0x328/0xfb0 [ 29.622172] [ 29.622172] which lock already depends on the new lock. [ 29.622172] [ 29.630460] [ 29.630460] the existing dependency chain (in reverse order) is: [ 29.638051] [ 29.638051] -> #1 (sk_lock-AF_INET){+.+.}: [ 29.643747] lock_sock_nested+0xb7/0x100 [ 29.648316] strp_work+0x3e/0x100 [ 29.652278] process_one_work+0x793/0x14a0 [ 29.657006] worker_thread+0x5cc/0xff0 [ 29.661524] kthread+0x30d/0x420 [ 29.665393] ret_from_fork+0x24/0x30 [ 29.669602] [ 29.669602] -> #0 ((&strp->work)){+.+.}: [ 29.675129] lock_acquire+0x170/0x3f0 [ 29.679437] flush_work+0xad/0x770 [ 29.683487] __cancel_work_timer+0x321/0x460 [ 29.688489] strp_done+0x53/0xd0 [ 29.692362] kcm_ioctl+0x828/0xfb0 [ 29.696401] sock_ioctl+0x2cc/0x4c0 [ 29.700524] do_vfs_ioctl+0x75a/0xff0 [ 29.704829] SyS_ioctl+0x7f/0xb0 [ 29.708695] do_syscall_64+0x1d5/0x640 [ 29.713102] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.718789] [ 29.718789] other info that might help us debug this: [ 29.718789] [ 29.726907] Possible unsafe locking scenario: [ 29.726907] [ 29.732937] CPU0 CPU1 [ 29.737576] ---- ---- [ 29.742235] lock(sk_lock-AF_INET); [ 29.745920] lock((&strp->work)); [ 29.751949] lock(sk_lock-AF_INET); [ 29.758150] lock((&strp->work)); [ 29.761661] [ 29.761661] *** DEADLOCK *** [ 29.761661] [ 29.767690] 1 lock held by syz-executor205/7967: [ 29.772414] #0: (sk_lock-AF_INET){+.+.}, at: [] kcm_ioctl+0x328/0xfb0 [ 29.780709] [ 29.780709] stack backtrace: [ 29.785177] CPU: 1 PID: 7967 Comm: syz-executor205 Not tainted 4.14.289-syzkaller #0 [ 29.793027] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 [ 29.802351] Call Trace: [ 29.804916] dump_stack+0x1b2/0x281 [ 29.808519] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 29.814290] __lock_acquire+0x2e0e/0x3f20 [ 29.818413] ? lock_acquire+0x170/0x3f0 [ 29.822360] ? trace_hardirqs_on+0x10/0x10 [ 29.826570] ? flush_work+0x88/0x770 [ 29.830255] lock_acquire+0x170/0x3f0 [ 29.834030] ? flush_work+0x88/0x770 [ 29.837719] ? flush_work+0x5a7/0x770 [ 29.841492] flush_work+0xad/0x770 [ 29.845002] ? flush_work+0x88/0x770 [ 29.848690] ? debug_object_active_state+0x330/0x330 [ 29.853764] ? worker_thread+0xff0/0xff0 [ 29.857796] ? trace_hardirqs_on+0x10/0x10 [ 29.862000] ? __debug_object_init+0x3fc/0x7a0 [ 29.866553] ? del_timer+0xb3/0xe0 [ 29.870064] ? process_timeout+0x20/0x20 [ 29.874098] ? mark_held_locks+0xa6/0xf0 [ 29.878131] ? __cancel_work_timer+0x2c1/0x460 [ 29.882688] __cancel_work_timer+0x321/0x460 [ 29.887069] ? work_on_cpu_safe+0x70/0x70 [ 29.891189] ? mark_held_locks+0xa6/0xf0 [ 29.895222] ? __local_bh_enable_ip+0xc1/0x170 [ 29.899795] strp_done+0x53/0xd0 [ 29.903134] kcm_ioctl+0x828/0xfb0 [ 29.906661] ? trace_hardirqs_on+0x10/0x10 [ 29.910869] ? kcm_release+0x700/0x700 [ 29.914731] ? futex_exit_release+0x220/0x220 [ 29.919198] sock_ioctl+0x2cc/0x4c0 [ 29.922806] ? sock_release+0x1e0/0x1e0 [ 29.926751] do_vfs_ioctl+0x75a/0xff0 [ 29.930522] ? lock_acquire+0x170/0x3f0 [ 29.934481] ? ioctl_preallocate+0x1a0/0x1a0 [ 29.938869] ? __fget+0x265/0x3e0 [ 29.942315] ? do_vfs_ioctl+0xff0/0xff0 [ 29.946262] ? security_file_ioctl+0x83/0xb0 [ 29.950641] SyS_ioctl+0x7f/0xb0 [ 29.953991] ? do_vfs_ioctl+0xff0/0xff0 [ 29.957939] do_syscall_64+0x1d5/0x640 [ 29.961800] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.966964] RIP: 0033:0x7f2e26462ea9 [ 29.97069