TITLE: BUG: unable to handle kernel NULL pointer dereference in sock_poll
ALT: bad-access in sock_poll
TYPE: NULL-POINTER-DEREFERENCE
PANICKED: Y

[   27.294614] random: sshd: uninitialized urandom read (32 bytes read)
[   27.396136] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[   27.404160] PGD 1b5d9f067 P4D 1b5d9f067 PUD 1affb3067 PMD 0 
[   27.409971] Oops: 0010 [#1] SMP KASAN
[   27.413759] CPU: 1 PID: 4557 Comm: syz-executor307 Not tainted 4.17.0+ #89
[   27.420761] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   27.430112] RIP: 0010:          (null)
[   27.433977] Code: Bad RIP value.
[   27.437337] RSP: 0018:ffff8801afb4f3a0 EFLAGS: 00010246
[   27.442687] RAX: 0000000000000000 RBX: ffff8801d96f3800 RCX: 1ffffffff10ea5ed
[   27.449978] RDX: ffff8801afb4fc00 RSI: ffff8801aba65600 RDI: ffff8801b0621080
[   27.457271] RBP: ffff8801afb4f510 R08: ffff8801afab4cf8 R09: 0000000000000006
[   27.464557] R10: ffff8801afab44c0 R11: 0000000000000000 R12: 1ffff10035f69e79
[   27.471838] R13: ffff8801afb4fc00 R14: ffff8801d96f3812 R15: ffff8801d96f3c58
[   27.479093] FS:  0000000001d2b880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
[   27.487391] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   27.493252] CR2: ffffffffffffffd6 CR3: 00000001b5858000 CR4: 00000000001406e0
[   27.500516] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   27.507765] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   27.515016] Call Trace:
[   27.517597]  ? smc_poll+0x211/0xdd0
[   27.521220]  ? __smc_connect+0xa90/0xa90
[   27.525261]  ? save_stack+0x43/0xd0
[   27.528881]  ? kasan_kmalloc+0xc4/0xe0
[   27.532748]  ? kasan_slab_alloc+0x12/0x20
[   27.536880]  ? kmem_cache_alloc+0x12e/0x760
[   27.541185]  ? ep_insert+0x270/0x1c00
[   27.544974]  ? __x64_sys_epoll_ctl+0xef1/0x10f0
[   27.549631]  ? do_syscall_64+0x1b1/0x800
[   27.553676]  ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   27.559040]  ? graph_lock+0x170/0x170
[   27.562825]  ? debug_check_no_locks_freed+0x310/0x310
[   27.567995]  ? handle_mm_fault+0x53a/0xc70
[   27.572218]  ? find_held_lock+0x36/0x1c0
[   27.576271]  ? print_usage_bug+0xc0/0xc0
[   27.580316]  sock_poll+0x1d1/0x710
[   27.583839]  ? __smc_connect+0xa90/0xa90
[   27.587885]  ? sock_get_poll_head+0x460/0x460
[   27.592380]  ? sock_get_poll_head+0x460/0x460
[   27.596873]  vfs_poll+0x77/0x2a0
[   27.600226]  ep_item_poll.isra.15+0x2c1/0x390
[   27.604705]  ? rcu_read_lock_sched_held+0x108/0x120
[   27.609701]  ? ep_eventpoll_poll+0x1f0/0x1f0
[   27.614092]  ? ep_insert+0x270/0x1c00
[   27.617873]  ep_insert+0x6b8/0x1c00
[   27.621485]  ? ep_send_events_proc+0xee0/0xee0
[   27.626053]  ? lock_release+0xa10/0xa10
[   27.630009]  ? check_same_owner+0x320/0x320
[   27.634318]  ? rcu_note_context_switch+0x710/0x710
[   27.639247]  ? __might_sleep+0x95/0x190
[   27.643206]  ? kasan_check_write+0x14/0x20
[   27.647439]  ? __mutex_lock+0x7d9/0x17f0
[   27.651485]  ? __x64_sys_epoll_ctl+0x518/0x10f0
[   27.656137]  ? find_held_lock+0x36/0x1c0
[   27.660181]  ? mutex_trylock+0x2a0/0x2a0
[   27.664221]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   27.669220]  ? graph_lock+0x170/0x170
[   27.673004]  ? lockdep_init_map+0x9/0x10
[   27.677054]  ? debug_mutex_init+0x2d/0x60
[   27.681181]  ? pud_val+0x80/0xf0
[   27.684539]  ? pmd_val+0xf0/0xf0
[   27.687889]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   27.693410]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   27.698929]  ? __handle_mm_fault+0x93a/0x4310
[   27.703425]  ? find_held_lock+0x36/0x1c0
[   27.707473]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   27.713011]  ? __fget_light+0x2ef/0x430
[   27.716991]  ? fget_raw+0x20/0x20
[   27.720433]  ? find_held_lock+0x36/0x1c0
[   27.724502]  ? __might_sleep+0x95/0x190
[   27.728458]  ? clear_tfile_check_list+0x380/0x380
[   27.733282]  ? __sanitizer_cov_trace_switch+0x53/0x90
[   27.738455]  __x64_sys_epoll_ctl+0xef1/0x10f0
[   27.742968]  ? __ia32_sys_epoll_create+0x70/0x70
[   27.747732]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   27.753253]  ? __do_page_fault+0x441/0xe40
[   27.757481]  ? mm_fault_error+0x380/0x380
[   27.761614]  ? __ia32_sys_fallocate+0xf0/0xf0
[   27.766097]  ? do_syscall_64+0x92/0x800
[   27.770076]  do_syscall_64+0x1b1/0x800
[   27.773952]  ? syscall_return_slowpath+0x5c0/0x5c0
[   27.778863]  ? syscall_return_slowpath+0x30f/0x5c0
[   27.783776]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   27.789301]  ? retint_user+0x18/0x18
[   27.793001]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   27.797832]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   27.803007] RIP: 0033:0x43fcc9
[   27.806199] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 6b 45 00 00 c3 66 2e 0f 1f 84 00 00 00 00 
[   27.825321] RSP: 002b:00007ffdf746b148 EFLAGS: 00000217 ORIG_RAX: 00000000000000e9
[   27.833031] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fcc9
[   27.840297] RDX: 0000000000000003 RSI: 0000000000000001 RDI: 0000000000000004
[   27.847550] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   27.854800] R10: 0000000020000000 R11: 0000000000000217 R12: 00000000004015f0
[   27.862059] R13: 0000000000401680 R14: 0000000000000000 R15: 0000000000000000
[   27.869311] Modules linked in:
[   27.872492] Dumping ftrace buffer:
[   27.876013]    (ftrace buffer empty)
[   27.879706] CR2: 0000000000000000
[   27.883769] ---[ end trace 64c0103aec0131a5 ]---
[   27.888586] RIP: 0010:          (null)
[   27.892502] Code: Bad RIP value.
[   27.895905] RSP: 0018:ffff8801afb4f3a0 EFLAGS: 00010246
[   27.901308] RAX: 0000000000000000 RBX: ffff8801d96f3800 RCX: 1ffffffff10ea5ed
[   27.908601] RDX: ffff8801afb4fc00 RSI: ffff8801aba65600 RDI: ffff8801b0621080
[   27.915888] RBP: ffff8801afb4f510 R08: ffff8801afab4cf8 R09: 0000000000000006
[   27.923184] R10: ffff8801afab44c0 R11: 0000000000000000 R12: 1ffff10035f69e79
[   27.930483] R13: ffff8801afb4fc00 R14: ffff8801d96f3812 R15: ffff8801d96f3c58
[   27.937781] FS:  0000000001d2b880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
[   27.946039] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   27.951941] CR2: ffffffffffffffd6 CR3: 00000001b5858000 CR4: 00000000001406e0
[   27.959240] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   27.966563] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   27.973863] Kernel panic - not syncing: Fatal exception
[   27.979760] Dumping ftrace buffer:
[   27.983289]    (ftrace buffer empty)
[   27.986979] Kernel Offset: disabled
[   27.990589] Rebooting in 86400 seconds..
