[ 33.079040] audit: type=1800 audit(1582354258.869:33): pid=7153 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0 [ 33.105982] audit: type=1800 audit(1582354258.869:34): pid=7153 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 38.852649] random: sshd: uninitialized urandom read (32 bytes read) [ 39.065595] audit: type=1400 audit(1582354264.859:35): avc: denied { map } for pid=7326 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 [ 39.117375] random: sshd: uninitialized urandom read (32 bytes read) [ 39.841016] random: sshd: uninitialized urandom read (32 bytes read) [ 40.031506] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.193' (ECDSA) to the list of known hosts. [ 45.562406] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 45.683813] audit: type=1400 audit(1582354271.479:36): avc: denied { map } for pid=7338 comm="syz-executor793" path="/root/syz-executor793808508" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 45.736175] ================================================================== [ 45.736214] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 45.736220] Write of size 8 at addr ffff888085490708 by task syz-executor793/7349 [ 45.736223] [ 45.736231] CPU: 0 PID: 7349 Comm: syz-executor793 Not tainted 4.14.171-syzkaller #0 [ 45.736236] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.736239] Call Trace: [ 45.736250] dump_stack+0x142/0x197 [ 45.736260] ? con_shutdown+0x85/0x90 [ 45.736270] print_address_description.cold+0x7c/0x1dc [ 45.736279] ? con_shutdown+0x85/0x90 [ 45.736285] kasan_report.cold+0xa9/0x2af [ 45.736292] ? set_palette+0x140/0x140 [ 45.736301] __asan_report_store8_noabort+0x17/0x20 [ 45.736308] con_shutdown+0x85/0x90 [ 45.736317] release_tty+0xbf/0x7c0 [ 45.736326] tty_release_struct+0x3c/0x50 [ 45.736333] tty_release+0xaa3/0xd60 [ 45.736347] ? tty_release_struct+0x50/0x50 [ 45.736354] __fput+0x275/0x7a0 [ 45.736366] ____fput+0x16/0x20 [ 45.736376] task_work_run+0x114/0x190 [ 45.736390] do_exit+0xa1a/0x2cd0 [ 45.736403] ? mm_update_next_owner+0x5d0/0x5d0 [ 45.736415] ? up_read+0x1a/0x40 [ 45.736422] ? __do_page_fault+0x358/0xb80 [ 45.736431] do_group_exit+0x111/0x330 [ 45.736441] SyS_exit_group+0x1d/0x20 [ 45.736447] ? do_group_exit+0x330/0x330 [ 45.736455] do_syscall_64+0x1e8/0x640 [ 45.736462] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 45.736475] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.736482] RIP: 0033:0x43ff38 [ 45.736486] RSP: 002b:00007ffd103fc278 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 45.736495] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 45.736499] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 45.736504] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 45.736509] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 45.736514] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 45.736528] [ 45.736532] Allocated by task 7349: [ 45.736540] save_stack_trace+0x16/0x20 [ 45.736546] save_stack+0x45/0xd0 [ 45.736551] kasan_kmalloc+0xce/0xf0 [ 45.736557] kmem_cache_alloc_trace+0x152/0x790 [ 45.736563] vc_allocate+0x148/0x580 [ 45.736569] con_install+0x52/0x400 [ 45.736575] tty_init_dev+0xea/0x3a0 [ 45.736580] tty_open+0x414/0xa10 [ 45.736586] chrdev_open+0x207/0x590 [ 45.736593] do_dentry_open+0x73b/0xeb0 [ 45.736599] vfs_open+0x105/0x220 [ 45.736606] path_openat+0x917/0x3e50 [ 45.736611] do_filp_open+0x18e/0x250 [ 45.736617] do_sys_open+0x2c5/0x430 [ 45.736623] SyS_open+0x2d/0x40 [ 45.736629] do_syscall_64+0x1e8/0x640 [ 45.736635] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.736637] [ 45.736641] Freed by task 7350: [ 45.736646] save_stack_trace+0x16/0x20 [ 45.736651] save_stack+0x45/0xd0 [ 45.736657] kasan_slab_free+0x75/0xc0 [ 45.736663] kfree+0xcc/0x270 [ 45.736672] vt_disallocate_all+0x286/0x380 [ 45.736677] vt_ioctl+0x76b/0x2170 [ 45.736683] tty_ioctl+0x841/0x1320 [ 45.736688] do_vfs_ioctl+0x7ae/0x1060 [ 45.736694] SyS_ioctl+0x8f/0xc0 [ 45.736700] do_syscall_64+0x1e8/0x640 [ 45.736707] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.736709] [ 45.736714] The buggy address belongs to the object at ffff888085490600 [ 45.736714] which belongs to the cache kmalloc-2048 of size 2048 [ 45.736719] The buggy address is located 264 bytes inside of [ 45.736719] 2048-byte region [ffff888085490600, ffff888085490e00) [ 45.736722] The buggy address belongs to the page: [ 45.736729] page:ffffea0002152400 count:1 mapcount:0 mapping:ffff888085490600 index:0x0 compound_mapcount: 0 [ 45.736739] flags: 0xfffe0000008100(slab|head) [ 45.736749] raw: 00fffe0000008100 ffff888085490600 0000000000000000 0000000100000003 [ 45.736756] raw: ffffea00027e8ca0 ffffea000216fc20 ffff8880aa800c40 0000000000000000 [ 45.736760] page dumped because: kasan: bad access detected [ 45.736762] [ 45.736764] Memory state around the buggy address: [ 45.736770] ffff888085490600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.736776] ffff888085490680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.736781] >ffff888085490700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.736784] ^ [ 45.736789] ffff888085490780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.736794] ffff888085490800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.736797] ================================================================== [ 45.736799] Disabling lock debugging due to kernel taint [ 45.736803] Kernel panic - not syncing: panic_on_warn set ... [ 45.736803] [ 45.736810] CPU: 0 PID: 7349 Comm: syz-executor793 Tainted: G B 4.14.171-syzkaller #0 [ 45.736813] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.736816] Call Trace: [ 45.736823] dump_stack+0x142/0x197 [ 45.736830] ? con_shutdown+0x85/0x90 [ 45.736835] panic+0x1f9/0x42d [ 45.736840] ? add_taint.cold+0x16/0x16 [ 45.736848] ? lock_downgrade+0x740/0x740 [ 45.736857] kasan_end_report+0x47/0x4f [ 45.736863] kasan_report.cold+0x130/0x2af [ 45.736869] ? set_palette+0x140/0x140 [ 45.736875] __asan_report_store8_noabort+0x17/0x20 [ 45.736881] con_shutdown+0x85/0x90 [ 45.736886] release_tty+0xbf/0x7c0 [ 45.736894] tty_release_struct+0x3c/0x50 [ 45.736901] tty_release+0xaa3/0xd60 [ 45.736910] ? tty_release_struct+0x50/0x50 [ 45.736915] __fput+0x275/0x7a0 [ 45.736923] ____fput+0x16/0x20 [ 45.736929] task_work_run+0x114/0x190 [ 45.736937] do_exit+0xa1a/0x2cd0 [ 45.736946] ? mm_update_next_owner+0x5d0/0x5d0 [ 45.736954] ? up_read+0x1a/0x40 [ 45.736959] ? __do_page_fault+0x358/0xb80 [ 45.736974] do_group_exit+0x111/0x330 [ 45.736982] SyS_exit_group+0x1d/0x20 [ 45.736987] ? do_group_exit+0x330/0x330 [ 45.736993] do_syscall_64+0x1e8/0x640 [ 45.737002] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 45.737010] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.737014] RIP: 0033:0x43ff38 [ 45.737018] RSP: 002b:00007ffd103fc278 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 45.737024] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 45.737028] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 45.737033] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 45.737037] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 45.737040] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 45.738156] Kernel Offset: disabled [ 46.363587] Rebooting in 86400 seconds..