[ OK ] Started Getty on tty1. [ OK ] Reached target Login Prompts. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.15' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 29.175022] BUG: sleeping function called from invalid context at mm/slab.h:419 [ 29.182639] in_atomic(): 1, irqs_disabled(): 1, pid: 7980, name: syz-executor774 [ 29.190157] 3 locks held by syz-executor774/7980: [ 29.194969] #0: (&ep->mtx){+.+.}, at: [] SyS_epoll_ctl+0x516/0x2780 [ 29.203097] #1: (&dev->dev_mutex){+.+.}, at: [] v4l2_m2m_fop_poll+0x91/0x110 [ 29.212003] #2: (&(&q->done_lock)->rlock){....}, at: [] v4l2_m2m_poll+0x116/0x670 [ 29.221430] irq event stamp: 6648 [ 29.224855] hardirqs last enabled at (6647): [] _raw_spin_unlock_irqrestore+0x79/0xe0 [ 29.234444] hardirqs last disabled at (6648): [] _raw_spin_lock_irqsave+0x66/0xc0 [ 29.243605] softirqs last enabled at (3068): [] __do_softirq+0x68b/0x9ff [ 29.252071] softirqs last disabled at (3043): [] irq_exit+0x193/0x240 [ 29.260194] Preemption disabled at: [ 29.260198] [< (null)>] (null) [ 29.268615] CPU: 1 PID: 7980 Comm: syz-executor774 Not tainted 4.14.258-syzkaller #0 [ 29.276488] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.285814] Call Trace: [ 29.288386] dump_stack+0x1b2/0x281 [ 29.291992] ___might_sleep.cold+0x235/0x250 [ 29.296378] kmem_cache_alloc+0x284/0x3c0 [ 29.300502] ep_ptable_queue_proc+0x9e/0x370 [ 29.304903] v4l2_m2m_poll+0x583/0x670 [ 29.308766] ? ep_send_events_proc+0x9c0/0x9c0 [ 29.313323] ? v4l2_m2m_ctx_release+0x30/0x30 [ 29.317794] v4l2_m2m_fop_poll+0xa4/0x110 [ 29.321919] v4l2_poll+0x133/0x1d0 [ 29.325438] SyS_epoll_ctl+0x14af/0x2780 [ 29.329571] ? anon_inode_getfile+0x22e/0x2f0 [ 29.334319] ? SyS_epoll_create+0x170/0x170 [ 29.338628] ? ep_send_events_proc+0x9c0/0x9c0 [ 29.343190] ? get_epoll_tfile_raw_ptr+0x1a0/0x1a0 [ 29.348099] ? do_syscall_64+0x4c/0x640 [ 29.352051] ? SyS_epoll_create+0x170/0x170 [ 29.356412] do_syscall_64+0x1d5/0x640 [ 29.360283] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.365462] RIP: 0033:0x7f73a66dc1e9 [ 29.369147] RSP: 002b:00007ffd74d8c338 EFLAGS: 00000246 ORIG_RAX: 00000000000