[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty1. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ 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 '10.128.0.242' (ECDSA) to the list of known hosts. syzkaller login: [ 34.764756] BUG: sleeping function called from invalid context at mm/slab.h:422 [ 34.772400] in_atomic(): 1, irqs_disabled(): 1, pid: 8094, name: syz-executor545 [ 34.779917] 3 locks held by syz-executor545/8094: [ 34.784733] #0: 00000000737f5a1a (&ep->mtx){+.+.}, at: __se_sys_epoll_ctl+0x5d2/0x2b90 [ 34.792868] #1: 0000000094a9d112 (&dev->dev_mutex){+.+.}, at: v4l2_m2m_fop_poll+0x91/0x110 [ 34.801345] #2: 0000000021926e83 (&(&q->done_lock)->rlock){....}, at: v4l2_m2m_poll+0x140/0x720 [ 34.810255] irq event stamp: 6628 [ 34.813690] hardirqs last enabled at (6627): [] _raw_spin_unlock_irqrestore+0x79/0xe0 [ 34.823286] hardirqs last disabled at (6628): [] _raw_spin_lock_irqsave+0x66/0xc0 [ 34.832463] softirqs last enabled at (5520): [] __do_softirq+0x678/0x980 [ 34.840941] softirqs last disabled at (5503): [] irq_exit+0x215/0x260 [ 34.849153] Preemption disabled at: [ 34.849157] [<0000000000000000>] (null) [ 34.857617] CPU: 0 PID: 8094 Comm: syz-executor545 Not tainted 4.19.211-syzkaller #0 [ 34.865474] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.874870] Call Trace: [ 34.877441] dump_stack+0x1fc/0x2ef [ 34.881052] ___might_sleep.cold+0x235/0x250 [ 34.885443] kmem_cache_alloc+0x26d/0x370 [ 34.889693] ep_ptable_queue_proc+0xaf/0x390 [ 34.894085] v4l2_m2m_poll+0x633/0x720 [ 34.897954] ? ep_poll_wakeup_proc+0x40/0x40 [ 34.902343] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 34.906907] ? v4l2_m2m_ctx_release+0x30/0x30 [ 34.911416] v4l2_m2m_fop_poll+0xa4/0x110 [ 34.915544] v4l2_poll+0x146/0x1f0 [ 34.919067] ? v4l2_mmap+0x1f0/0x1f0 [ 34.922761] ep_item_poll+0x14a/0x3e0 [ 34.926542] ? ep_eventpoll_poll+0x160/0x160 [ 34.930928] ? __se_sys_epoll_ctl+0xc5b/0x2b90 [ 34.935500] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 34.940502] __se_sys_epoll_ctl+0x1b04/0x2b90 [ 34.944981] ? ep_loop_check_proc+0x4d0/0x4d0 [ 34.949455] ? __fd_install+0x1eb/0x610 [ 34.953412] ? do_epoll_create+0x149/0x1c0 [ 34.957627] ? ep_poll_wakeup_proc+0x40/0x40 [ 34.962023] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 34.967377] ? trace_hardirqs_off_caller+0x6e/0x210 [ 34.972373] ? do_syscall_64+0x21/0x620 [ 34.976328] do_syscall_64+0xf9/0x620 [ 34.980113] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.985301] RIP: 0033:0x7f9e48cdc1e9 [ 34.988992] Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 [ 35.007871] RSP: 002b:00007ffd92e964a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9 executing program [ 3