[ 33.777089] audit: type=1800 audit(1581398704.719:33): pid=7197 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 [ 33.804737] audit: type=1800 audit(1581398704.719:34): pid=7197 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: [ 39.199252] random: sshd: uninitialized urandom read (32 bytes read) [ 39.709324] audit: type=1400 audit(1581398710.649:35): avc: denied { map } for pid=7370 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 [ 39.760920] random: sshd: uninitialized urandom read (32 bytes read) [ 40.491252] random: sshd: uninitialized urandom read (32 bytes read) [ 40.681015] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.85' (ECDSA) to the list of known hosts. [ 46.236327] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 46.364172] audit: type=1400 audit(1581398717.309:36): avc: denied { map } for pid=7382 comm="syz-executor867" path="/root/syz-executor867397587" 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 [ 46.411931] ================================================================== [ 46.411963] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 46.411969] Write of size 8 at addr ffff888084280408 by task syz-executor867/7389 [ 46.411972] [ 46.411981] CPU: 1 PID: 7389 Comm: syz-executor867 Not tainted 4.14.170-syzkaller #0 [ 46.411985] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.411989] Call Trace: [ 46.412001] dump_stack+0x142/0x197 [ 46.412012] ? con_shutdown+0x85/0x90 [ 46.412022] print_address_description.cold+0x7c/0x1dc [ 46.412030] ? con_shutdown+0x85/0x90 [ 46.412046] kasan_report.cold+0xa9/0x2af [ 46.412055] ? set_palette+0x140/0x140 [ 46.412064] __asan_report_store8_noabort+0x17/0x20 [ 46.412072] con_shutdown+0x85/0x90 [ 46.412081] release_tty+0xbf/0x7c0 [ 46.412096] tty_release_struct+0x3c/0x50 [ 46.412104] tty_release+0xaa3/0xd60 [ 46.412118] ? tty_release_struct+0x50/0x50 [ 46.412126] __fput+0x275/0x7a0 [ 46.412139] ____fput+0x16/0x20 [ 46.412149] task_work_run+0x114/0x190 [ 46.412163] do_exit+0xa1a/0x2cd0 [ 46.412177] ? mm_update_next_owner+0x5d0/0x5d0 [ 46.412190] ? up_read+0x1a/0x40 [ 46.412198] ? __do_page_fault+0x358/0xb80 [ 46.412207] do_group_exit+0x111/0x330 [ 46.412218] SyS_exit_group+0x1d/0x20 [ 46.412255] ? do_group_exit+0x330/0x330 [ 46.412272] do_syscall_64+0x1e8/0x640 [ 46.412280] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 46.412292] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.412298] RIP: 0033:0x43ff38 [ 46.412302] RSP: 002b:00007ffcc5563a28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 46.412310] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 46.412314] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 46.412318] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 46.412322] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 46.412326] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 46.412338] [ 46.412341] Allocated by task 7389: [ 46.412350] save_stack_trace+0x16/0x20 [ 46.412356] save_stack+0x45/0xd0 [ 46.412362] kasan_kmalloc+0xce/0xf0 [ 46.412368] kmem_cache_alloc_trace+0x152/0x790 [ 46.412375] vc_allocate+0x148/0x580 [ 46.412382] con_install+0x52/0x400 [ 46.412388] tty_init_dev+0xea/0x3a0 [ 46.412395] tty_open+0x414/0xa10 [ 46.412401] chrdev_open+0x207/0x590 [ 46.412409] do_dentry_open+0x73b/0xeb0 [ 46.412415] vfs_open+0x105/0x220 [ 46.412427] path_openat+0x917/0x3e50 [ 46.412438] do_filp_open+0x18e/0x250 [ 46.412444] do_sys_open+0x2c5/0x430 [ 46.412451] SyS_open+0x2d/0x40 [ 46.412456] do_syscall_64+0x1e8/0x640 [ 46.412462] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.412463] [ 46.412466] Freed by task 7390: [ 46.412470] save_stack_trace+0x16/0x20 [ 46.412475] save_stack+0x45/0xd0 [ 46.412479] kasan_slab_free+0x75/0xc0 [ 46.412484] kfree+0xcc/0x270 [ 46.412490] vt_disallocate_all+0x286/0x380 [ 46.412495] vt_ioctl+0x76b/0x2170 [ 46.412501] tty_ioctl+0x841/0x1320 [ 46.412508] do_vfs_ioctl+0x7ae/0x1060 [ 46.412514] SyS_ioctl+0x8f/0xc0 [ 46.412520] do_syscall_64+0x1e8/0x640 [ 46.412526] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.412528] [ 46.412533] The buggy address belongs to the object at ffff888084280300 [ 46.412533] which belongs to the cache kmalloc-2048 of size 2048 [ 46.412539] The buggy address is located 264 bytes inside of [ 46.412539] 2048-byte region [ffff888084280300, ffff888084280b00) [ 46.412542] The buggy address belongs to the page: [ 46.412553] page:ffffea000210a000 count:1 mapcount:0 mapping:ffff888084280300 index:0x0 compound_mapcount: 0 [ 46.412564] flags: 0xfffe0000008100(slab|head) [ 46.412574] raw: 00fffe0000008100 ffff888084280300 0000000000000000 0000000100000003 [ 46.412583] raw: ffffea00027ed4a0 ffffea0002679720 ffff8880aa800c40 0000000000000000 [ 46.412586] page dumped because: kasan: bad access detected [ 46.412588] [ 46.412591] Memory state around the buggy address: [ 46.412597] ffff888084280300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.412602] ffff888084280380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.412607] >ffff888084280400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.412610] ^ [ 46.412615] ffff888084280480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.412620] ffff888084280500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.412622] ================================================================== [ 46.412625] Disabling lock debugging due to kernel taint [ 46.412629] Kernel panic - not syncing: panic_on_warn set ... [ 46.412629] [ 46.412636] CPU: 1 PID: 7389 Comm: syz-executor867 Tainted: G B 4.14.170-syzkaller #0 [ 46.412640] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.412642] Call Trace: [ 46.412651] dump_stack+0x142/0x197 [ 46.412660] ? con_shutdown+0x85/0x90 [ 46.412665] panic+0x1f9/0x42d [ 46.412670] ? add_taint.cold+0x16/0x16 [ 46.412680] ? lock_downgrade+0x740/0x740 [ 46.412690] kasan_end_report+0x47/0x4f [ 46.412697] kasan_report.cold+0x130/0x2af [ 46.412703] ? set_palette+0x140/0x140 [ 46.412712] __asan_report_store8_noabort+0x17/0x20 [ 46.412718] con_shutdown+0x85/0x90 [ 46.412725] release_tty+0xbf/0x7c0 [ 46.412733] tty_release_struct+0x3c/0x50 [ 46.412740] tty_release+0xaa3/0xd60 [ 46.412750] ? tty_release_struct+0x50/0x50 [ 46.412755] __fput+0x275/0x7a0 [ 46.412763] ____fput+0x16/0x20 [ 46.412771] task_work_run+0x114/0x190 [ 46.412781] do_exit+0xa1a/0x2cd0 [ 46.412791] ? mm_update_next_owner+0x5d0/0x5d0 [ 46.412799] ? up_read+0x1a/0x40 [ 46.412805] ? __do_page_fault+0x358/0xb80 [ 46.412811] do_group_exit+0x111/0x330 [ 46.412818] SyS_exit_group+0x1d/0x20 [ 46.412824] ? do_group_exit+0x330/0x330 [ 46.412830] do_syscall_64+0x1e8/0x640 [ 46.412837] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 46.412847] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.412852] RIP: 0033:0x43ff38 [ 46.412856] RSP: 002b:00007ffcc5563a28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 46.412863] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 46.412867] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 46.412871] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 46.412875] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 46.412878] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 46.414686] Kernel Offset: disabled [ 47.040841] Rebooting in 86400 seconds..