[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 31.381439] random: sshd: uninitialized urandom read (32 bytes read) [ 31.646756] kauditd_printk_skb: 9 callbacks suppressed [ 31.646763] audit: type=1400 audit(1576209014.320:35): avc: denied { map } for pid=6938 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 31.695242] random: sshd: uninitialized urandom read (32 bytes read) [ 32.250539] random: sshd: uninitialized urandom read (32 bytes read) [ 489.852642] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.69' (ECDSA) to the list of known hosts. [ 495.515295] 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 [ 495.628789] audit: type=1400 audit(1576209478.300:36): avc: denied { map } for pid=6953 comm="syz-executor927" path="/root/syz-executor927213161" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 502.701223] ================================================================== [ 502.701404] BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x1feb/0x2410 [ 502.701412] Read of size 1 at addr ffff8880a0664040 by task syz-executor927/8246 [ 502.701414] [ 502.701424] CPU: 1 PID: 8246 Comm: syz-executor927 Not tainted 4.14.158-syzkaller #0 [ 502.701429] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 502.701451] Call Trace: [ 502.701499] dump_stack+0x142/0x197 [ 502.701511] ? n_tty_receive_buf_common+0x1feb/0x2410 [ 502.701545] print_address_description.cold+0x7c/0x1dc [ 502.701555] ? n_tty_receive_buf_common+0x1feb/0x2410 [ 502.701562] kasan_report.cold+0xa9/0x2af [ 502.701572] __asan_report_load1_noabort+0x14/0x20 [ 502.701580] n_tty_receive_buf_common+0x1feb/0x2410 [ 502.701604] n_tty_receive_buf2+0x34/0x40 [ 502.701614] ? n_tty_receive_buf_common+0x2410/0x2410 [ 502.701620] tty_ldisc_receive_buf+0xa5/0x1a0 [ 502.701639] paste_selection+0x1e6/0x3f2 [ 502.701680] ? find_held_lock+0x35/0x130 [ 502.701691] ? set_selection+0xe30/0xe30 [ 502.701702] ? lock_downgrade+0x740/0x740 [ 502.701726] ? wake_up_q+0xf0/0xf0 [ 502.701740] tioclinux+0x10e/0x400 [ 502.701749] vt_ioctl+0x180c/0x2170 [ 502.701776] ? avc_has_extended_perms+0x8ec/0xe40 [ 502.701786] ? complete_change_console+0x360/0x360 [ 502.701794] ? avc_ss_reset+0x110/0x110 [ 502.701807] ? do_raw_spin_unlock+0x16b/0x260 [ 502.701815] ? tty_jobctrl_ioctl+0x44/0xc10 [ 502.701847] ? _raw_spin_unlock+0x2d/0x50 [ 502.701853] ? complete_change_console+0x360/0x360 [ 502.701863] tty_ioctl+0x841/0x1320 [ 502.701872] ? tty_vhangup+0x30/0x30 [ 502.701887] ? __might_sleep+0x93/0xb0 [ 502.701893] ? save_trace+0x290/0x290 [ 502.701905] ? tty_vhangup+0x30/0x30 [ 502.701936] do_vfs_ioctl+0x7ae/0x1060 [ 502.701945] ? selinux_file_mprotect+0x5d0/0x5d0 [ 502.701955] ? ioctl_preallocate+0x1c0/0x1c0 [ 502.701963] ? lock_downgrade+0x740/0x740 [ 502.701995] ? security_file_ioctl+0x7d/0xb0 [ 502.702001] ? security_file_ioctl+0x89/0xb0 [ 502.702010] SyS_ioctl+0x8f/0xc0 [ 502.702017] ? do_vfs_ioctl+0x1060/0x1060 [ 502.702028] do_syscall_64+0x1e8/0x640 [ 502.702035] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 502.702048] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 502.702055] RIP: 0033:0x441329 [ 502.702060] RSP: 002b:00007ffd23725cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 502.702068] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441329 [ 502.702072] RDX: 0000000020000140 RSI: 000000000000541c RDI: 0000000000000003 [ 502.702076] RBP: 000000000007ab6a R08: 000000000000000d R09: 00000000004002c8 [ 502.702081] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020a0 [ 502.702085] R13: 0000000000402130 R14: 0000000000000000 R15: 0000000000000000 [ 502.702097] [ 502.702125] Allocated by task 8242: [ 502.702137] save_stack_trace+0x16/0x20 [ 502.702143] save_stack+0x45/0xd0 [ 502.978691] kasan_kmalloc+0xce/0xf0 [ 502.978697] __kmalloc+0x15d/0x7a0 [ 502.978706] set_selection+0x79a/0xe30 [ 502.989809] tioclinux+0xf7/0x400 [ 502.989815] vt_ioctl+0x180c/0x2170 [ 502.989821] tty_ioctl+0x841/0x1320 [ 502.989828] do_vfs_ioctl+0x7ae/0x1060 [ 502.989833] SyS_ioctl+0x8f/0xc0 [ 502.989841] do_syscall_64+0x1e8/0x640 [ 502.989849] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 502.989852] [ 502.989856] Freed by task 8243: [ 502.989863] save_stack_trace+0x16/0x20 [ 502.989868] save_stack+0x45/0xd0 [ 502.989874] kasan_slab_free+0x75/0xc0 [ 502.989879] kfree+0xcc/0x270 [ 502.989884] set_selection+0x7b7/0xe30 [ 502.989889] tioclinux+0xf7/0x400 [ 502.989894] vt_ioctl+0x180c/0x2170 [ 502.989900] tty_ioctl+0x841/0x1320 [ 502.989906] do_vfs_ioctl+0x7ae/0x1060 [ 502.989912] SyS_ioctl+0x8f/0xc0 [ 502.989917] do_syscall_64+0x1e8/0x640 [ 502.989924] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 502.989926] [ 502.989931] The buggy address belongs to the object at ffff8880a0664040 [ 502.989931] which belongs to the cache kmalloc-32 of size 32 [ 502.989938] The buggy address is located 0 bytes inside of [ 502.989938] 32-byte region [ffff8880a0664040, ffff8880a0664060) [ 502.989942] The buggy address belongs to the page: [ 502.989948] page:ffffea0002819900 count:1 mapcount:0 mapping:ffff8880a0664000 index:0xffff8880a0664fc1 [ 503.097447] flags: 0xfffe0000000100(slab) [ 503.097455] raw: 00fffe0000000100 ffff8880a0664000 ffff8880a0664fc1 000000010000003f [ 503.097462] raw: ffffea00026431e0 ffffea0002809120 ffff8880aa8001c0 0000000000000000 [ 503.126856] page dumped because: kasan: bad access detected [ 503.126860] [ 503.126863] Memory state around the buggy address: [ 503.126870] ffff8880a0663f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 503.126877] ffff8880a0663f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 503.153812] >ffff8880a0664000: 00 00 00 07 fc fc fc fc fb fb fb fb fc fc fc fc [ 503.153818] ^ [ 503.153824] ffff8880a0664080: 00 00 00 07 fc fc fc fc fb fb fb fb fc fc fc fc [ 503.153828] ffff8880a0664100: 00 00 01 fc fc fc fc fc fb fb fb fb fc fc fc fc [ 503.153831] ================================================================== [ 503.153833] Disabling lock debugging due to kernel taint [ 503.154334] Kernel panic - not syncing: panic_on_warn set ... [ 503.154334] [ 503.201638] CPU: 1 PID: 8246 Comm: syz-executor927 Tainted: G B 4.14.158-syzkaller #0 [ 503.201642] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 503.201644] Call Trace: [ 503.201660] dump_stack+0x142/0x197 [ 503.201672] ? n_tty_receive_buf_common+0x1feb/0x2410 [ 503.201751] panic+0x1f9/0x42d [ 503.201760] ? add_taint.cold+0x16/0x16 [ 503.238793] ? ___preempt_schedule+0x16/0x18 [ 503.238805] kasan_end_report+0x47/0x4f [ 503.238811] kasan_report.cold+0x130/0x2af [ 503.238818] __asan_report_load1_noabort+0x14/0x20 [ 503.238828] n_tty_receive_buf_common+0x1feb/0x2410 [ 503.238842] n_tty_receive_buf2+0x34/0x40 [ 503.238849] ? n_tty_receive_buf_common+0x2410/0x2410 [ 503.238855] tty_ldisc_receive_buf+0xa5/0x1a0 [ 503.238863] paste_selection+0x1e6/0x3f2 [ 503.238872] ? find_held_lock+0x35/0x130 [ 503.238879] ? set_selection+0xe30/0xe30 [ 503.238887] ? lock_downgrade+0x740/0x740 [ 503.238895] ? wake_up_q+0xf0/0xf0 [ 503.238903] tioclinux+0x10e/0x400 [ 503.238909] vt_ioctl+0x180c/0x2170 [ 503.238918] ? avc_has_extended_perms+0x8ec/0xe40 [ 503.307503] ? complete_change_console+0x360/0x360 [ 503.307511] ? avc_ss_reset+0x110/0x110 [ 503.307520] ? do_raw_spin_unlock+0x16b/0x260 [ 503.307527] ? tty_jobctrl_ioctl+0x44/0xc10 [ 503.307534] ? _raw_spin_unlock+0x2d/0x50 [ 503.307540] ? complete_change_console+0x360/0x360 [ 503.307548] tty_ioctl+0x841/0x1320 [ 503.307557] ? tty_vhangup+0x30/0x30 [ 503.307568] ? __might_sleep+0x93/0xb0 [ 503.307576] ? save_trace+0x290/0x290 [ 503.307584] ? tty_vhangup+0x30/0x30 [ 503.307592] do_vfs_ioctl+0x7ae/0x1060 [ 503.307599] ? selinux_file_mprotect+0x5d0/0x5d0 [ 503.307607] ? ioctl_preallocate+0x1c0/0x1c0 [ 503.307613] ? lock_downgrade+0x740/0x740 [ 503.307622] ? security_file_ioctl+0x7d/0xb0 [ 503.307628] ? security_file_ioctl+0x89/0xb0 [ 503.307636] SyS_ioctl+0x8f/0xc0 [ 503.307642] ? do_vfs_ioctl+0x1060/0x1060 [ 503.307651] do_syscall_64+0x1e8/0x640 [ 503.307657] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 503.307666] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 503.307672] RIP: 0033:0x441329 [ 503.307675] RSP: 002b:00007ffd23725cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 503.307683] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441329 [ 503.307687] RDX: 0000000020000140 RSI: 000000000000541c RDI: 0000000000000003 [ 503.307690] RBP: 000000000007ab6a R08: 000000000000000d R09: 00000000004002c8 [ 503.307694] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020a0 [ 503.307703] R13: 0000000000402130 R14: 0000000000000000 R15: 0000000000000000 [ 503.314014] Kernel Offset: disabled [ 503.452732] Rebooting in 86400 seconds..