[ 32.893072] audit: type=1800 audit(1581696626.514:33): pid=7098 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 [ 32.921064] audit: type=1800 audit(1581696626.514:34): pid=7098 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: [ 36.092600] random: sshd: uninitialized urandom read (32 bytes read) [ 36.335686] audit: type=1400 audit(1581696629.954:35): avc: denied { map } for pid=7274 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 [ 36.411879] random: sshd: uninitialized urandom read (32 bytes read) [ 37.146891] random: sshd: uninitialized urandom read (32 bytes read) [ 42.825739] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.2' (ECDSA) to the list of known hosts. [ 48.427830] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 48.543201] audit: type=1400 audit(1581696642.164:36): avc: denied { map } for pid=7286 comm="syz-executor311" path="/root/syz-executor311220616" 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 [ 48.597045] ================================================================== [ 48.597076] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 48.597082] Write of size 8 at addr ffff8880a9e49608 by task syz-executor311/7294 [ 48.597085] [ 48.597093] CPU: 1 PID: 7294 Comm: syz-executor311 Not tainted 4.14.170-syzkaller #0 [ 48.597098] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.597101] Call Trace: [ 48.597112] dump_stack+0x142/0x197 [ 48.597123] ? ocfs2_prepare_dx_dir_for_insert.isra.0+0xca8/0x1380 [ 48.597133] ? con_shutdown+0x85/0x90 [ 48.597142] print_address_description.cold+0x7c/0x1dc [ 48.597151] ? con_shutdown+0x85/0x90 [ 48.597159] kasan_report.cold+0xa9/0x2af [ 48.597167] ? set_palette+0x140/0x140 [ 48.597177] __asan_report_store8_noabort+0x17/0x20 [ 48.597184] con_shutdown+0x85/0x90 [ 48.597194] release_tty+0xbf/0x7c0 [ 48.597204] tty_release_struct+0x3c/0x50 [ 48.597213] tty_release+0xaa3/0xd60 [ 48.597227] ? tty_release_struct+0x50/0x50 [ 48.597235] __fput+0x275/0x7a0 [ 48.597248] ____fput+0x16/0x20 [ 48.597258] task_work_run+0x114/0x190 [ 48.597271] do_exit+0xa1a/0x2cd0 [ 48.597285] ? mm_update_next_owner+0x5d0/0x5d0 [ 48.597299] ? up_read+0x1a/0x40 [ 48.597314] ? __do_page_fault+0x358/0xb80 [ 48.597324] do_group_exit+0x111/0x330 [ 48.597335] SyS_exit_group+0x1d/0x20 [ 48.597342] ? do_group_exit+0x330/0x330 [ 48.597351] do_syscall_64+0x1e8/0x640 [ 48.597359] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.597374] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.597381] RIP: 0033:0x43ff38 [ 48.597386] RSP: 002b:00007ffe0b9b2528 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 48.597395] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 48.597400] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 48.597405] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 48.597409] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 48.597414] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 48.597429] [ 48.597433] Allocated by task 7294: [ 48.597441] save_stack_trace+0x16/0x20 [ 48.597447] save_stack+0x45/0xd0 [ 48.597453] kasan_kmalloc+0xce/0xf0 [ 48.597459] kmem_cache_alloc_trace+0x152/0x790 [ 48.597466] vc_allocate+0x148/0x580 [ 48.597472] con_install+0x52/0x400 [ 48.597479] tty_init_dev+0xea/0x3a0 [ 48.597485] tty_open+0x414/0xa10 [ 48.597492] chrdev_open+0x207/0x590 [ 48.597499] do_dentry_open+0x73b/0xeb0 [ 48.597506] vfs_open+0x105/0x220 [ 48.597512] path_openat+0x917/0x3e50 [ 48.597518] do_filp_open+0x18e/0x250 [ 48.597525] do_sys_open+0x2c5/0x430 [ 48.597531] SyS_open+0x2d/0x40 [ 48.597538] do_syscall_64+0x1e8/0x640 [ 48.597545] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.597547] [ 48.597551] Freed by task 7295: [ 48.597557] save_stack_trace+0x16/0x20 [ 48.597562] save_stack+0x45/0xd0 [ 48.597568] kasan_slab_free+0x75/0xc0 [ 48.597574] kfree+0xcc/0x270 [ 48.597580] vt_disallocate_all+0x286/0x380 [ 48.597585] vt_ioctl+0x76b/0x2170 [ 48.597591] tty_ioctl+0x841/0x1320 [ 48.597598] do_vfs_ioctl+0x7ae/0x1060 [ 48.597604] SyS_ioctl+0x8f/0xc0 [ 48.597611] do_syscall_64+0x1e8/0x640 [ 48.597618] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.597620] [ 48.597626] The buggy address belongs to the object at ffff8880a9e49500 [ 48.597626] which belongs to the cache kmalloc-2048 of size 2048 [ 48.597632] The buggy address is located 264 bytes inside of [ 48.597632] 2048-byte region [ffff8880a9e49500, ffff8880a9e49d00) [ 48.597635] The buggy address belongs to the page: [ 48.597641] page:ffffea0002a79200 count:1 mapcount:0 mapping:ffff8880a9e48400 index:0x0 compound_mapcount: 0 [ 48.597651] flags: 0xfffe0000008100(slab|head) [ 48.597660] raw: 00fffe0000008100 ffff8880a9e48400 0000000000000000 0000000100000003 [ 48.597669] raw: ffffea00024465a0 ffffea0002a319a0 ffff8880aa800c40 0000000000000000 [ 48.597672] page dumped because: kasan: bad access detected [ 48.597675] [ 48.597677] Memory state around the buggy address: [ 48.597683] ffff8880a9e49500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.597689] ffff8880a9e49580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.597694] >ffff8880a9e49600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.597698] ^ [ 48.597703] ffff8880a9e49680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.597708] ffff8880a9e49700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.597711] ================================================================== [ 48.597714] Disabling lock debugging due to kernel taint [ 48.597745] Kernel panic - not syncing: panic_on_warn set ... [ 48.597745] [ 48.597752] CPU: 1 PID: 7294 Comm: syz-executor311 Tainted: G B 4.14.170-syzkaller #0 [ 48.597755] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.597757] Call Trace: [ 48.597766] dump_stack+0x142/0x197 [ 48.597775] ? con_shutdown+0x85/0x90 [ 48.597780] panic+0x1f9/0x42d [ 48.597786] ? add_taint.cold+0x16/0x16 [ 48.597797] kasan_end_report+0x47/0x4f [ 48.597804] kasan_report.cold+0x130/0x2af [ 48.597810] ? set_palette+0x140/0x140 [ 48.597817] __asan_report_store8_noabort+0x17/0x20 [ 48.597824] con_shutdown+0x85/0x90 [ 48.597831] release_tty+0xbf/0x7c0 [ 48.597839] tty_release_struct+0x3c/0x50 [ 48.597846] tty_release+0xaa3/0xd60 [ 48.597857] ? tty_release_struct+0x50/0x50 [ 48.597862] __fput+0x275/0x7a0 [ 48.597871] ____fput+0x16/0x20 [ 48.597878] task_work_run+0x114/0x190 [ 48.597887] do_exit+0xa1a/0x2cd0 [ 48.597896] ? mm_update_next_owner+0x5d0/0x5d0 [ 48.597905] ? up_read+0x1a/0x40 [ 48.597911] ? __do_page_fault+0x358/0xb80 [ 48.597919] do_group_exit+0x111/0x330 [ 48.597926] SyS_exit_group+0x1d/0x20 [ 48.597931] ? do_group_exit+0x330/0x330 [ 48.597937] do_syscall_64+0x1e8/0x640 [ 48.597944] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.597953] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.597958] RIP: 0033:0x43ff38 [ 48.597961] RSP: 002b:00007ffe0b9b2528 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 48.597968] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 48.597972] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 48.597976] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 48.597979] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 48.597983] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 48.599207] Kernel Offset: disabled