[ 32.461212] audit: type=1800 audit(1583908963.608:33): 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 [ 32.491403] audit: type=1800 audit(1583908963.608:34): 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: [ 37.811078] random: sshd: uninitialized urandom read (32 bytes read) [ 38.091484] audit: type=1400 audit(1583908969.238:35): avc: denied { map } for pid=7270 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 [ 38.141866] random: sshd: uninitialized urandom read (32 bytes read) [ 38.844896] random: sshd: uninitialized urandom read (32 bytes read) [ 54.427988] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.6' (ECDSA) to the list of known hosts. [ 59.974428] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 60.091794] audit: type=1400 audit(1583908991.238:36): avc: denied { map } for pid=7283 comm="syz-executor700" path="/root/syz-executor700251389" 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 [ 60.143850] ================================================================== [ 60.143892] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 60.143899] Write of size 8 at addr ffff8880a5802248 by task syz-executor700/7292 [ 60.143901] [ 60.143909] CPU: 1 PID: 7292 Comm: syz-executor700 Not tainted 4.14.172-syzkaller #0 [ 60.143914] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.143917] Call Trace: [ 60.143929] dump_stack+0x13e/0x194 [ 60.143940] ? con_shutdown+0x7f/0x90 [ 60.143950] print_address_description.cold+0x7c/0x1e2 [ 60.143959] ? con_shutdown+0x7f/0x90 [ 60.143967] kasan_report.cold+0xa9/0x2ae [ 60.143975] ? set_palette+0x130/0x130 [ 60.143983] con_shutdown+0x7f/0x90 [ 60.143997] release_tty+0xb6/0x7a0 [ 60.144008] tty_release_struct+0x37/0x50 [ 60.144015] tty_release+0xaa6/0xd60 [ 60.144029] ? tty_release_struct+0x50/0x50 [ 60.144037] __fput+0x25f/0x790 [ 60.144056] task_work_run+0x113/0x190 [ 60.144069] do_exit+0x9f2/0x2b00 [ 60.144084] ? __do_page_fault+0x4e4/0xb40 [ 60.144094] ? mm_update_next_owner+0x5b0/0x5b0 [ 60.144103] ? lock_downgrade+0x6e0/0x6e0 [ 60.144120] do_group_exit+0x100/0x310 [ 60.144130] SyS_exit_group+0x19/0x20 [ 60.144137] ? do_group_exit+0x310/0x310 [ 60.144145] do_syscall_64+0x1d5/0x640 [ 60.144159] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 60.144166] RIP: 0033:0x43ff38 [ 60.144171] RSP: 002b:00007ffd24da33e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 60.144180] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 60.144184] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 60.144189] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 60.144194] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 60.144198] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 60.144212] [ 60.144216] Allocated by task 7292: [ 60.144223] save_stack+0x32/0xa0 [ 60.144229] kasan_kmalloc+0xbf/0xe0 [ 60.144235] kmem_cache_alloc_trace+0x14d/0x7b0 [ 60.144241] vc_allocate+0x142/0x550 [ 60.144247] con_install+0x4f/0x3e0 [ 60.144253] tty_init_dev+0xe1/0x3a0 [ 60.144259] tty_open+0x410/0x9c0 [ 60.144265] chrdev_open+0x1fc/0x540 [ 60.144273] do_dentry_open+0x732/0xe90 [ 60.144278] vfs_open+0x105/0x220 [ 60.144285] path_openat+0x8ca/0x3c50 [ 60.144291] do_filp_open+0x18e/0x250 [ 60.144297] do_sys_open+0x29d/0x3f0 [ 60.144303] do_syscall_64+0x1d5/0x640 [ 60.144310] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 60.144312] [ 60.144315] Freed by task 7295: [ 60.144320] save_stack+0x32/0xa0 [ 60.144326] kasan_slab_free+0x75/0xc0 [ 60.144330] kfree+0xcb/0x260 [ 60.144338] vt_disallocate_all+0x25c/0x340 [ 60.144343] vt_ioctl+0x6e3/0x1f00 [ 60.144349] tty_ioctl+0x6c5/0x1220 [ 60.144355] do_vfs_ioctl+0x75a/0xfe0 [ 60.144361] SyS_ioctl+0x7f/0xb0 [ 60.144367] do_syscall_64+0x1d5/0x640 [ 60.144373] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 60.144375] [ 60.144380] The buggy address belongs to the object at ffff8880a5802140 [ 60.144380] which belongs to the cache kmalloc-2048 of size 2048 [ 60.144386] The buggy address is located 264 bytes inside of [ 60.144386] 2048-byte region [ffff8880a5802140, ffff8880a5802940) [ 60.144389] The buggy address belongs to the page: [ 60.144395] page:ffffea0002960080 count:1 mapcount:0 mapping:ffff8880a5802140 index:0x0 compound_mapcount: 0 [ 60.144406] flags: 0xfffe0000008100(slab|head) [ 60.144416] raw: 00fffe0000008100 ffff8880a5802140 0000000000000000 0000000100000003 [ 60.144425] raw: ffffea0002260120 ffffea0002176920 ffff88812fe56c40 0000000000000000 [ 60.144428] page dumped because: kasan: bad access detected [ 60.144430] [ 60.144432] Memory state around the buggy address: [ 60.144438] ffff8880a5802100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 60.144443] ffff8880a5802180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.144449] >ffff8880a5802200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.144452] ^ [ 60.144458] ffff8880a5802280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.144463] ffff8880a5802300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.144465] ================================================================== [ 60.144468] Disabling lock debugging due to kernel taint [ 60.144545] Kernel panic - not syncing: panic_on_warn set ... [ 60.144545] [ 60.144552] CPU: 1 PID: 7292 Comm: syz-executor700 Tainted: G B 4.14.172-syzkaller #0 [ 60.144555] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.144557] Call Trace: [ 60.144566] dump_stack+0x13e/0x194 [ 60.144573] panic+0x1f9/0x42d [ 60.144579] ? add_taint.cold+0x16/0x16 [ 60.144586] ? preempt_schedule_common+0x4a/0xc0 [ 60.144594] ? con_shutdown+0x7f/0x90 [ 60.144601] ? ___preempt_schedule+0x16/0x18 [ 60.144610] ? con_shutdown+0x7f/0x90 [ 60.144617] kasan_end_report+0x43/0x49 [ 60.144623] kasan_report.cold+0x12f/0x2ae [ 60.144630] ? set_palette+0x130/0x130 [ 60.144637] con_shutdown+0x7f/0x90 [ 60.144643] release_tty+0xb6/0x7a0 [ 60.144651] tty_release_struct+0x37/0x50 [ 60.144657] tty_release+0xaa6/0xd60 [ 60.144667] ? tty_release_struct+0x50/0x50 [ 60.144672] __fput+0x25f/0x790 [ 60.144682] task_work_run+0x113/0x190 [ 60.144690] do_exit+0x9f2/0x2b00 [ 60.144697] ? __do_page_fault+0x4e4/0xb40 [ 60.144705] ? mm_update_next_owner+0x5b0/0x5b0 [ 60.144712] ? lock_downgrade+0x6e0/0x6e0 [ 60.144722] do_group_exit+0x100/0x310 [ 60.144730] SyS_exit_group+0x19/0x20 [ 60.144736] ? do_group_exit+0x310/0x310 [ 60.144742] do_syscall_64+0x1d5/0x640 [ 60.144751] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 60.144755] RIP: 0033:0x43ff38 [ 60.144759] RSP: 002b:00007ffd24da33e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 60.144765] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 60.144768] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 60.144772] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 60.144775] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 60.144779] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 60.146128] Kernel Offset: disabled [ 60.740728] Rebooting in 86400 seconds..