BUG: sleeping function called from invalid context at mm/slab.h:419 in_atomic(): 1, irqs_disabled(): 1, pid: 13717, name: syz-executor.2 MINIX-fs: unable to read superblock 3 locks held by syz-executor.2/13717: #0: (&ep->mtx){+.+.}, at: [] SYSC_epoll_ctl fs/eventpoll.c:2080 [inline] #0: (&ep->mtx){+.+.}, at: [] SyS_epoll_ctl+0x516/0x2780 fs/eventpoll.c:2002 #1: (&dev->dev_mutex){+.+.}, at: [] v4l2_m2m_fop_poll+0x91/0x110 drivers/media/v4l2-core/v4l2-mem2mem.c:802 #2: (&(&q->done_lock)->rlock){....}, at: [] v4l2_m2m_poll+0x116/0x670 drivers/media/v4l2-core/v4l2-mem2mem.c:536 irq event stamp: 258 hardirqs last enabled at (257): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (257): [] _raw_spin_unlock_irqrestore+0x79/0xe0 kernel/locking/spinlock.c:192 hardirqs last disabled at (258): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (258): [] _raw_spin_lock_irqsave+0x66/0xc0 kernel/locking/spinlock.c:160 softirqs last enabled at (0): [] copy_process.part.0+0x12d0/0x71c0 kernel/fork.c:1734 softirqs last disabled at (0): [< (null)>] (null) Preemption disabled at: [< (null)>] (null) CPU: 1 PID: 13717 Comm: syz-executor.2 Not tainted 4.14.261-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 ___might_sleep.cold+0x235/0x250 kernel/sched/core.c:6041 slab_pre_alloc_hook mm/slab.h:419 [inline] slab_alloc mm/slab.c:3376 [inline] kmem_cache_alloc+0x284/0x3c0 mm/slab.c:3550 ep_ptable_queue_proc+0x9e/0x370 fs/eventpoll.c:1255 poll_wait include/linux/poll.h:50 [inline] v4l2_m2m_poll+0x583/0x670 drivers/media/v4l2-core/v4l2-mem2mem.c:538 v4l2_m2m_fop_poll+0xa4/0x110 drivers/media/v4l2-core/v4l2-mem2mem.c:804 v4l2_poll+0x133/0x1d0 drivers/media/v4l2-core/v4l2-dev.c:342 ep_item_poll fs/eventpoll.c:885 [inline] ep_insert fs/eventpoll.c:1490 [inline] SYSC_epoll_ctl fs/eventpoll.c:2117 [inline] SyS_epoll_ctl+0x14af/0x2780 fs/eventpoll.c:2002 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f41d35d8e99 RSP: 002b:00007f41d1f4e168 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9 RAX: ffffffffffffffda RBX: 00007f41d36ebf60 RCX: 00007f41d35d8e99 RDX: 0000000000000003 RSI: 0000000000000001 RDI: 0000000000000004 RBP: 00007f41d3632ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe8baf245f R14: 00007f41d1f4e300 R15: 0000000000022000 print_req_error: I/O error, dev loop4, sector 0 Buffer I/O error on dev loop4, logical block 0, async page read print_req_error: I/O error, dev loop4, sector 2 Buffer I/O error on dev loop4, logical block 1, async page read MINIX-fs: unable to read superblock MINIX-fs: unable to read superblock print_req_error: I/O error, dev loop4, sector 0 Buffer I/O error on dev loop4, logical block 0, async page read print_req_error: I/O error, dev loop4, sector 2 Buffer I/O error on dev loop4, logical block 1, async page read MINIX-fs: unable to read superblock unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1