[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 23.662774] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 27.223137] random: sshd: uninitialized urandom read (32 bytes read) [ 27.530095] random: sshd: uninitialized urandom read (32 bytes read) [ 28.054723] random: sshd: uninitialized urandom read (32 bytes read) [ 28.233925] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.31' (ECDSA) to the list of known hosts. [ 33.884606] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 33.983850] divide error: 0000 [#1] SMP KASAN [ 33.988484] CPU: 0 PID: 4667 Comm: syz-executor024 Not tainted 4.19.0-rc1+ #216 [ 33.995920] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.005286] RIP: 0010:nbd_ioctl+0x53c/0xcf0 [ 34.009592] 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 [ 34.028505] RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246 [ 34.033859] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 [ 34.041126] RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0 [ 34.048396] RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d [ 34.055650] R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000 [ 34.062902] R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840 [ 34.070156] FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 [ 34.078363] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 34.084226] CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0 [ 34.091491] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 34.098755] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 34.106006] Call Trace: [ 34.108588] ? nbd_release+0x140/0x140 [ 34.112466] ? kasan_check_read+0x11/0x20 [ 34.116614] ? rcu_is_watching+0x8c/0x150 [ 34.120744] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 34.125399] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 34.130054] ? is_bpf_text_address+0xd7/0x170 [ 34.134543] ? nbd_release+0x140/0x140 [ 34.138416] blkdev_ioctl+0x9cd/0x2030 [ 34.142292] ? unwind_get_return_address+0x61/0xa0 [ 34.147205] ? blkpg_ioctl+0xc40/0xc40 [ 34.151091] ? save_stack+0xa9/0xd0 [ 34.154705] ? save_stack+0x43/0xd0 [ 34.158317] ? __kasan_slab_free+0x11a/0x170 [ 34.162725] ? kasan_slab_free+0xe/0x10 [ 34.166682] ? kmem_cache_free+0x86/0x280 [ 34.170813] ? putname+0xf2/0x130 [ 34.174249] ? do_sys_open+0x569/0x720 [ 34.178120] ? __x64_sys_open+0x7e/0xc0 [ 34.182090] ? do_syscall_64+0x1b9/0x820 [ 34.186185] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.191542] ? trace_hardirqs_off+0xb8/0x2b0 [ 34.195939] ? kasan_check_read+0x11/0x20 [ 34.200084] ? do_raw_spin_unlock+0xa7/0x2f0 [ 34.204483] ? trace_hardirqs_on+0x2c0/0x2c0 [ 34.208886] ? kasan_check_write+0x14/0x20 [ 34.213108] block_ioctl+0xee/0x130 [ 34.216716] ? blkdev_fallocate+0x400/0x400 [ 34.221035] do_vfs_ioctl+0x1de/0x1720 [ 34.224906] ? kasan_check_read+0x11/0x20 [ 34.229055] ? rcu_is_watching+0x8c/0x150 [ 34.233201] ? trace_hardirqs_on+0xbd/0x2c0 [ 34.237507] ? ioctl_preallocate+0x300/0x300 [ 34.241902] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.247423] ? __fget_light+0x2f7/0x440 [ 34.251381] ? putname+0xf2/0x130 [ 34.254817] ? fget_raw+0x20/0x20 [ 34.258256] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.263257] ? kmem_cache_free+0x246/0x280 [ 34.267491] ? do_syscall_64+0x9a/0x820 [ 34.271466] ? do_syscall_64+0x9a/0x820 [ 34.275438] ? lockdep_hardirqs_on+0x421/0x5c0 [ 34.280030] ? security_file_ioctl+0x94/0xc0 [ 34.284422] ksys_ioctl+0xa9/0xd0 [ 34.287866] __x64_sys_ioctl+0x73/0xb0 [ 34.291754] do_syscall_64+0x1b9/0x820 [ 34.295627] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 34.300975] ? syscall_return_slowpath+0x5e0/0x5e0 [ 34.305891] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.310717] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 34.315717] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 34.320746] ? prepare_exit_to_usermode+0x291/0x3b0 [ 34.325761] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.330589] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.335767] RIP: 0033:0x443d29 [ 34.338953] 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 [ 34.357853] RSP: 002b:00007ffe343644d8 EFLAGS: 00000213 ORIG_RAX: 0000000000000010 [ 34.365560] RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d29 [ 34.372810] RDX: 0000000000000000 RSI: 000000000000ab01 RDI: 0000000000000003 [ 34.380101] RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0 [ 34.387352] R10: 000000000000000f R11: 0000000000000213 R12: 0000000000401a30 [ 34.394777] R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000 [ 34.402046] Modules linked in: [ 34.405237] Dumping ftrace buffer: [ 34.408757] (ftrace buffer empty) [ 34.412590] ---[ end trace 25c60c4714d4e2ee ]--- [ 34.417378] RIP: 0010:nbd_ioctl+0x53c/0xcf0 [ 34.421717] 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 [ 34.440640] RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246 [ 34.446022] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 [ 34.453302] RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0 [ 34.460588] RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d [ 34.467875] R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000 [ 34.475163] R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840 [ 34.482447] FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 [ 34.490703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 34.496598] CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0 [ 34.503887] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 34.511170] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 34.518459] Kernel panic - not syncing: Fatal exception [ 34.524177] Dumping ftrace buffer: [ 34.527721] (ftrace buffer empty) [ 34.531413] Kernel Offset: disabled [ 34.535023] Rebooting in 86400 seconds..