[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 12.718511] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 13.035110] random: sshd: uninitialized urandom read (32 bytes read) [ 13.280407] random: sshd: uninitialized urandom read (32 bytes read) [ 13.738001] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 100.270696] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.38' (ECDSA) to the list of known hosts. [ 105.910782] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program INIT: Id "1" respawning too fast: disabled for 5 minutes executing program executing program INIT: Id "6" respawning too fast: disabled for 5 minutes INIT: Id "3" respawning too fast: disabled for 5 minutes INIT: Id "5" respawning too fast: disabled for 5 minutes INIT: Id "4" respawning too fast: disabled for 5 minutes INIT: Id "2" respawning too fast: disabled for 5 minutes executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 145.899578] ================================================================== [ 145.907006] BUG: KASAN: use-after-free in disk_unblock_events+0x4b/0x50 [ 145.913757] Read of size 8 at addr ffff8801bea4afe8 by task blkid/2915 [ 145.920413] [ 145.922037] CPU: 1 PID: 2915 Comm: blkid Not tainted 4.14.67+ #1 [ 145.928169] Call Trace: [ 145.930754] dump_stack+0xb9/0x11b [ 145.934305] print_address_description+0x60/0x22b [ 145.939153] kasan_report.cold.6+0x11b/0x2dd [ 145.943560] ? disk_unblock_events+0x4b/0x50 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 145.947972] disk_unblock_events+0x4b/0x50 [ 145.952204] __blkdev_get+0x68f/0xe50 [ 145.956004] ? trace_hardirqs_on+0x10/0x10 [ 145.960244] ? __blkdev_put+0x6e0/0x6e0 [ 145.964229] ? check_preemption_disabled+0x34/0x160 [ 145.969244] ? fsnotify+0x639/0x12d0 [ 145.972979] blkdev_get+0x97/0x8c0 [ 145.976525] ? bd_may_claim+0xe0/0xe0 [ 145.980329] ? bd_acquire+0x171/0x2c0 [ 145.984133] ? lock_downgrade+0x560/0x560 [ 145.988284] ? lock_acquire+0x10f/0x380 [ 145.992278] ? bd_acquire+0x21/0x2c0 [ 145.996017] blkdev_open+0x1bd/0x240 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 145.999731] ? security_file_open+0x88/0x190 [ 146.004142] do_dentry_open+0x426/0xda0 [ 146.008115] ? bd_acquire+0x2c0/0x2c0 [ 146.011927] vfs_open+0x11c/0x210 [ 146.015388] path_openat+0x4eb/0x23a0 [ 146.019200] ? path_mountpoint+0x9a0/0x9a0 [ 146.023439] ? kasan_kmalloc.part.1+0x4f/0xd0 [ 146.027937] ? trace_hardirqs_on+0x10/0x10 [ 146.032192] do_filp_open+0x197/0x270 [ 146.035996] ? may_open_dev+0xd0/0xd0 [ 146.039814] ? _raw_spin_unlock+0x29/0x40 [ 146.043976] do_sys_open+0x2ef/0x580 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.047693] ? filp_open+0x60/0x60 [ 146.051234] ? up_read+0x17/0x30 [ 146.054612] ? __do_page_fault+0x64c/0xb60 [ 146.058851] ? do_syscall_64+0x43/0x4b0 [ 146.062822] ? do_sys_open+0x580/0x580 [ 146.066712] do_syscall_64+0x19b/0x4b0 [ 146.070604] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 146.075789] RIP: 0033:0x7fa656a61120 [ 146.079492] RSP: 002b:00007ffce04aa0f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 146.087198] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa656a61120 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.094464] RDX: 00007ffce04abf34 RSI: 0000000000000000 RDI: 00007ffce04abf34 [ 146.101732] RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 [ 146.109000] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000bbf030 [ 146.116263] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 [ 146.123562] [ 146.125184] Allocated by task 2907: [ 146.128809] kasan_kmalloc.part.1+0x4f/0xd0 [ 146.133305] kmem_cache_alloc_trace+0x138/0x300 [ 146.137982] alloc_disk_node+0x5f/0x3b0 [ 146.141954] loop_add+0x3e9/0x840 [ 146.145408] loop_control_ioctl+0x12e/0x310 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.149722] do_vfs_ioctl+0x1a0/0x1030 [ 146.153610] SyS_ioctl+0x7e/0xb0 [ 146.156971] do_syscall_64+0x19b/0x4b0 [ 146.160854] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 146.166031] [ 146.167681] Freed by task 2915: [ 146.170973] kasan_slab_free+0xac/0x190 [ 146.174938] kfree+0xf5/0x310 [ 146.178038] device_release+0xf4/0x1a0 [ 146.181919] kobject_put+0x146/0x200 [ 146.185629] put_disk+0x1f/0x30 [ 146.188907] __blkdev_get+0x5fa/0xe50 [ 146.192703] blkdev_get+0x97/0x8c0 [ 146.196238] blkdev_open+0x1bd/0x240 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.200053] do_dentry_open+0x426/0xda0 [ 146.204179] vfs_open+0x11c/0x210 [ 146.207627] path_openat+0x4eb/0x23a0 [ 146.211426] do_filp_open+0x197/0x270 [ 146.215220] do_sys_open+0x2ef/0x580 [ 146.218929] do_syscall_64+0x19b/0x4b0 [ 146.222818] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 146.227995] [ 146.229619] The buggy address belongs to the object at ffff8801bea4aa80 [ 146.229619] which belongs to the cache kmalloc-2048 of size 2048 [ 146.242447] The buggy address is located 1384 bytes inside of executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.242447] 2048-byte region [ffff8801bea4aa80, ffff8801bea4b280) [ 146.254486] The buggy address belongs to the page: [ 146.259413] page:ffffea0006fa9200 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 146.269378] flags: 0x4000000000008100(slab|head) [ 146.274134] raw: 4000000000008100 0000000000000000 0000000000000000 00000001000f000f [ 146.282014] raw: dead000000000100 dead000000000200 ffff8801d6802800 0000000000000000 [ 146.289890] page dumped because: kasan: bad access detected [ 146.295588] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.297205] Memory state around the buggy address: [ 146.302124] ffff8801bea4ae80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 146.309483] ffff8801bea4af00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 146.316837] >ffff8801bea4af80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 146.324203] ^ [ 146.330950] ffff8801bea4b000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 146.338319] ffff8801bea4b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.345668] ================================================================== [ 146.353026] Disabling lock debugging due to kernel taint [ 146.385033] Kernel panic - not syncing: panic_on_warn set ... [ 146.385033] [ 146.392438] CPU: 1 PID: 2915 Comm: blkid Tainted: G B 4.14.67+ #1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.399790] Call Trace: [ 146.402377] dump_stack+0xb9/0x11b [ 146.405918] panic+0x1bf/0x3a4 [ 146.409107] ? add_taint.cold.4+0x16/0x16 [ 146.413252] ? ___preempt_schedule+0x16/0x18 [ 146.419151] kasan_end_report+0x43/0x49 [ 146.423123] kasan_report.cold.6+0x77/0x2dd [ 146.427439] ? disk_unblock_events+0x4b/0x50 [ 146.431886] disk_unblock_events+0x4b/0x50 [ 146.436116] __blkdev_get+0x68f/0xe50 [ 146.439919] ? trace_hardirqs_on+0x10/0x10 [ 146.444151] ? __blkdev_put+0x6e0/0x6e0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.448123] ? check_preemption_disabled+0x34/0x160 [ 146.453135] ? fsnotify+0x639/0x12d0 [ 146.456850] blkdev_get+0x97/0x8c0 [ 146.460387] ? bd_may_claim+0xe0/0xe0 [ 146.464180] ? bd_acquire+0x171/0x2c0 [ 146.467981] ? lock_downgrade+0x560/0x560 [ 146.472123] ? lock_acquire+0x10f/0x380 [ 146.476092] ? bd_acquire+0x21/0x2c0 [ 146.479810] blkdev_open+0x1bd/0x240 [ 146.483519] ? security_file_open+0x88/0x190 [ 146.487926] do_dentry_open+0x426/0xda0 [ 146.491891] ? bd_acquire+0x2c0/0x2c0 [ 146.495692] vfs_open+0x11c/0x210 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.499142] path_openat+0x4eb/0x23a0 [ 146.502948] ? path_mountpoint+0x9a0/0x9a0 [ 146.507189] ? kasan_kmalloc.part.1+0x4f/0xd0 [ 146.511685] ? trace_hardirqs_on+0x10/0x10 [ 146.515925] do_filp_open+0x197/0x270 [ 146.519722] ? may_open_dev+0xd0/0xd0 [ 146.523536] ? _raw_spin_unlock+0x29/0x40 [ 146.527713] do_sys_open+0x2ef/0x580 [ 146.531466] ? filp_open+0x60/0x60 [ 146.535006] ? up_read+0x17/0x30 [ 146.538368] ? __do_page_fault+0x64c/0xb60 [ 146.542601] ? do_syscall_64+0x43/0x4b0 [ 146.546579] ? do_sys_open+0x580/0x580 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 146.550464] do_syscall_64+0x19b/0x4b0 [ 146.554350] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 146.559529] RIP: 0033:0x7fa656a61120 [ 146.563234] RSP: 002b:00007ffce04aa0f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 146.570961] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa656a61120 [ 146.578232] RDX: 00007ffce04abf34 RSI: 0000000000000000 RDI: 00007ffce04abf34 [ 146.585496] RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 [ 146.592757] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000bbf030 executing program executing program executing program executing program [ 146.600019] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 [ 146.607664] Dumping ftrace buffer: [ 146.611190] (ftrace buffer empty) [ 146.614875] Kernel Offset: 0x1a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 146.625696] Rebooting in 86400 seconds..