[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 24.589089] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [ 25.527620] random: sshd: uninitialized urandom read (32 bytes read) [ 25.734122] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 26.290139] random: sshd: uninitialized urandom read (32 bytes read) [ 31.934406] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.17' (ECDSA) to the list of known hosts. [ 37.502968] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 37.602549] divide error: 0000 [#1] SMP KASAN [ 37.607084] CPU: 1 PID: 4665 Comm: syz-executor637 Not tainted 4.19.0-rc1+ #217 [ 37.614509] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.623856] RIP: 0010:nbd_ioctl+0x53c/0xcf0 [ 37.628162] Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8 fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c [ 37.647046] RSP: 0018:ffff8801b8d77828 EFLAGS: 00010246 [ 37.652400] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 [ 37.659655] RDX: 0000000000000000 RSI: ffff8801d9feaa40 RDI: ffff8801d9feab00 [ 37.666925] RBP: ffff8801b8d779a0 R08: ffff8801be820540 R09: ffffed003a6434bd [ 37.674179] R10: ffff8801b8d77818 R11: ffff8801d321a5ef R12: ffff8801d321a500 [ 37.681432] R13: 00000000ffffffe7 R14: ffff8801d321a5e0 R15: ffff8801da806040 [ 37.688750] FS: 0000000000965880(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 [ 37.696976] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 37.702843] CR2: 000000000043e560 CR3: 00000001d8396000 CR4: 00000000001406e0 [ 37.710101] Call Trace: [ 37.712676] ? nbd_release+0x140/0x140 [ 37.716556] ? kasan_check_read+0x11/0x20 [ 37.720695] ? rcu_is_watching+0x8c/0x150 [ 37.724835] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 37.729488] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 37.734143] ? is_bpf_text_address+0xd7/0x170 [ 37.738619] ? nbd_release+0x140/0x140 [ 37.742487] blkdev_ioctl+0x9cd/0x2030 [ 37.746358] ? unwind_get_return_address+0x61/0xa0 [ 37.751274] ? blkpg_ioctl+0xc40/0xc40 [ 37.755152] ? save_stack+0xa9/0xd0 [ 37.758764] ? save_stack+0x43/0xd0 [ 37.762375] ? __kasan_slab_free+0x11a/0x170 [ 37.766768] ? kasan_slab_free+0xe/0x10 [ 37.770773] ? kmem_cache_free+0x86/0x280 [ 37.774917] ? putname+0xf2/0x130 [ 37.778494] ? do_sys_open+0x569/0x720 [ 37.782405] ? __x64_sys_open+0x7e/0xc0 [ 37.786371] ? do_syscall_64+0x1b9/0x820 [ 37.790420] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.795769] ? trace_hardirqs_off+0xb8/0x2b0 [ 37.800174] ? kasan_check_read+0x11/0x20 [ 37.804310] ? do_raw_spin_unlock+0xa7/0x2f0 [ 37.808709] ? trace_hardirqs_on+0x2c0/0x2c0 [ 37.813170] ? kasan_check_write+0x14/0x20 [ 37.817472] block_ioctl+0xee/0x130 [ 37.821090] ? blkdev_fallocate+0x400/0x400 [ 37.825395] do_vfs_ioctl+0x1de/0x1720 [ 37.829269] ? kasan_check_read+0x11/0x20 [ 37.833404] ? rcu_is_watching+0x8c/0x150 [ 37.837537] ? trace_hardirqs_on+0xbd/0x2c0 [ 37.841850] ? ioctl_preallocate+0x300/0x300 [ 37.846245] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.851766] ? __fget_light+0x2f7/0x440 [ 37.855733] ? putname+0xf2/0x130 [ 37.859238] ? fget_raw+0x20/0x20 [ 37.862682] ? rcu_read_lock_sched_held+0x108/0x120 [ 37.867707] ? kmem_cache_free+0x246/0x280 [ 37.871930] ? do_syscall_64+0x9a/0x820 [ 37.875890] ? do_syscall_64+0x9a/0x820 [ 37.879856] ? lockdep_hardirqs_on+0x421/0x5c0 [ 37.884426] ? security_file_ioctl+0x94/0xc0 [ 37.888829] ksys_ioctl+0xa9/0xd0 [ 37.892276] __x64_sys_ioctl+0x73/0xb0 [ 37.896155] do_syscall_64+0x1b9/0x820 [ 37.900028] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 37.905441] ? syscall_return_slowpath+0x5e0/0x5e0 [ 37.910358] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 37.915185] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 37.920185] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 37.925228] ? prepare_exit_to_usermode+0x291/0x3b0 [ 37.930226] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 37.935053] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.940223] RIP: 0033:0x443d29 [ 37.943402] 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 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 37.962286] RSP: 002b:00007ffda2752558 EFLAGS: 00000213 ORIG_RAX: 0000000000000010 [ 37.969977] RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d29 [ 37.977227] RDX: 0000000000000000 RSI: 000000000000ab01 RDI: 0000000000000003 [ 37.984479] RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0 [ 37.991732] R10: 000000000000000f R11: 0000000000000213 R12: 0000000000401a30 [ 37.998983] R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000 [ 38.006298] Modules linked in: [ 38.009490] Dumping ftrace buffer: [ 38.013015] (ftrace buffer empty) [ 38.016856] ---[ end trace 8558bfb901e639af ]--- [ 38.021644] RIP: 0010:nbd_ioctl+0x53c/0xcf0 [ 38.025993] Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8 fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c [ 38.044931] RSP: 0018:ffff8801b8d77828 EFLAGS: 00010246 [ 38.050315] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 [ 38.057601] RDX: 0000000000000000 RSI: ffff8801d9feaa40 RDI: ffff8801d9feab00 [ 38.064895] RBP: ffff8801b8d779a0 R08: ffff8801be820540 R09: ffffed003a6434bd [ 38.072184] R10: ffff8801b8d77818 R11: ffff8801d321a5ef R12: ffff8801d321a500 [ 38.079572] R13: 00000000ffffffe7 R14: ffff8801d321a5e0 R15: ffff8801da806040 [ 38.086870] FS: 0000000000965880(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 [ 38.095112] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 38.101068] CR2: 000000000043e560 CR3: 00000001d8396000 CR4: 00000000001406e0 [ 38.108364] Kernel panic - not syncing: Fatal exception [ 38.114079] Dumping ftrace buffer: [ 38.117604] (ftrace buffer empty) [ 38.121295] Kernel Offset: disabled [ 38.124900] Rebooting in 86400 seconds..