[ 34.621626] audit: type=1800 audit(1585038376.539:33): pid=7198 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 [ 34.649075] audit: type=1800 audit(1585038376.539:34): pid=7198 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: [ 37.980418] random: sshd: uninitialized urandom read (32 bytes read) [ 38.354593] audit: type=1400 audit(1585038380.269:35): avc: denied { map } for pid=7369 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 [ 38.406315] random: sshd: uninitialized urandom read (32 bytes read) [ 39.107950] random: sshd: uninitialized urandom read (32 bytes read) [ 39.290285] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.85' (ECDSA) to the list of known hosts. [ 45.038417] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program [ 45.162595] audit: type=1400 audit(1585038387.079:36): avc: denied { map } for pid=7381 comm="syz-executor930" path="/root/syz-executor930401012" 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 [ 45.222349] ================================================================== [ 45.222381] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 45.222387] Write of size 8 at addr ffff8880945481c8 by task syz-executor930/7389 [ 45.222389] [ 45.222397] CPU: 0 PID: 7389 Comm: syz-executor930 Not tainted 4.14.174-syzkaller #0 [ 45.222402] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.222405] Call Trace: [ 45.222416] dump_stack+0x13e/0x194 [ 45.222426] ? con_shutdown+0x7f/0x90 [ 45.222437] print_address_description.cold+0x7c/0x1e2 [ 45.222445] ? con_shutdown+0x7f/0x90 [ 45.222451] kasan_report.cold+0xa9/0x2ae [ 45.222459] ? set_palette+0x130/0x130 [ 45.222466] con_shutdown+0x7f/0x90 [ 45.222475] release_tty+0xb6/0x7a0 [ 45.222485] tty_release_struct+0x37/0x50 [ 45.222493] tty_release+0xaa6/0xd60 [ 45.222507] ? tty_release_struct+0x50/0x50 [ 45.222514] __fput+0x25f/0x790 [ 45.222529] task_work_run+0x113/0x190 [ 45.222542] do_exit+0x9f2/0x2b00 [ 45.222551] ? __do_page_fault+0x4e4/0xb40 [ 45.222560] ? mm_update_next_owner+0x5b0/0x5b0 [ 45.222569] ? lock_downgrade+0x6e0/0x6e0 [ 45.222582] do_group_exit+0x100/0x310 [ 45.222591] SyS_exit_group+0x19/0x20 [ 45.222597] ? do_group_exit+0x310/0x310 [ 45.222605] do_syscall_64+0x1d5/0x640 [ 45.222617] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.222623] RIP: 0033:0x43ff58 [ 45.222627] RSP: 002b:00007ffc01896e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 45.222636] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff58 [ 45.222640] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 45.222644] RBP: 00000000004bf970 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 45.222649] R10: 000000000000000e R11: 0000000000000246 R12: 0000000000000001 [ 45.222653] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 45.222666] [ 45.222670] Allocated by task 7389: [ 45.222676] save_stack+0x32/0xa0 [ 45.222682] kasan_kmalloc+0xbf/0xe0 [ 45.222688] kmem_cache_alloc_trace+0x14d/0x7b0 [ 45.222694] vc_allocate+0x142/0x550 [ 45.222701] con_install+0x4f/0x3e0 [ 45.222707] tty_init_dev+0xe1/0x3a0 [ 45.222713] tty_open+0x410/0x9c0 [ 45.222719] chrdev_open+0x1fc/0x540 [ 45.222726] do_dentry_open+0x732/0xe90 [ 45.222732] vfs_open+0x105/0x220 [ 45.222739] path_openat+0x8ca/0x3c50 [ 45.222745] do_filp_open+0x18e/0x250 [ 45.222752] do_sys_open+0x29d/0x3f0 [ 45.222758] do_syscall_64+0x1d5/0x640 [ 45.222765] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.222767] [ 45.222771] Freed by task 7393: [ 45.222776] save_stack+0x32/0xa0 [ 45.222783] kasan_slab_free+0x75/0xc0 [ 45.222787] kfree+0xcb/0x260 [ 45.222793] vt_disallocate_all+0x25c/0x340 [ 45.222799] vt_ioctl+0x6e3/0x1f00 [ 45.222805] tty_ioctl+0x6c5/0x1220 [ 45.222809] do_vfs_ioctl+0x75a/0xfe0 [ 45.222815] SyS_ioctl+0x7f/0xb0 [ 45.222821] do_syscall_64+0x1d5/0x640 [ 45.222828] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.222830] [ 45.222835] The buggy address belongs to the object at ffff8880945480c0 [ 45.222835] which belongs to the cache kmalloc-2048 of size 2048 [ 45.222841] The buggy address is located 264 bytes inside of [ 45.222841] 2048-byte region [ffff8880945480c0, ffff8880945488c0) [ 45.222844] The buggy address belongs to the page: [ 45.222850] page:ffffea0002515200 count:1 mapcount:0 mapping:ffff8880945480c0 index:0x0 compound_mapcount: 0 [ 45.222861] flags: 0xfffe0000008100(slab|head) [ 45.222870] raw: 00fffe0000008100 ffff8880945480c0 0000000000000000 0000000100000003 [ 45.222879] raw: ffffea00024c59a0 ffffea00025179a0 ffff88812fe56c40 0000000000000000 [ 45.222882] page dumped because: kasan: bad access detected [ 45.222885] [ 45.222887] Memory state around the buggy address: [ 45.222893] ffff888094548080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 45.222899] ffff888094548100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.222905] >ffff888094548180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.222908] ^ [ 45.222914] ffff888094548200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.222919] ffff888094548280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.222922] ================================================================== [ 45.222925] Disabling lock debugging due to kernel taint [ 45.222929] Kernel panic - not syncing: panic_on_warn set ... [ 45.222929] [ 45.222936] CPU: 0 PID: 7389 Comm: syz-executor930 Tainted: G B 4.14.174-syzkaller #0 [ 45.222939] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.222941] Call Trace: [ 45.222957] dump_stack+0x13e/0x194 [ 45.222964] panic+0x1f9/0x42d [ 45.222970] ? add_taint.cold+0x16/0x16 [ 45.222978] ? lock_downgrade+0x6e0/0x6e0 [ 45.222987] ? con_shutdown+0x7f/0x90 [ 45.222992] kasan_end_report+0x43/0x49 [ 45.222999] kasan_report.cold+0x12f/0x2ae [ 45.223006] ? set_palette+0x130/0x130 [ 45.223012] con_shutdown+0x7f/0x90 [ 45.223019] release_tty+0xb6/0x7a0 [ 45.223026] tty_release_struct+0x37/0x50 [ 45.223033] tty_release+0xaa6/0xd60 [ 45.223043] ? tty_release_struct+0x50/0x50 [ 45.223048] __fput+0x25f/0x790 [ 45.223058] task_work_run+0x113/0x190 [ 45.223066] do_exit+0x9f2/0x2b00 [ 45.223073] ? __do_page_fault+0x4e4/0xb40 [ 45.223081] ? mm_update_next_owner+0x5b0/0x5b0 [ 45.223087] ? lock_downgrade+0x6e0/0x6e0 [ 45.223097] do_group_exit+0x100/0x310 [ 45.223104] SyS_exit_group+0x19/0x20 [ 45.223110] ? do_group_exit+0x310/0x310 [ 45.223116] do_syscall_64+0x1d5/0x640 [ 45.223125] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 45.223129] RIP: 0033:0x43ff58 [ 45.223133] RSP: 002b:00007ffc01896e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 45.223138] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff58 [ 45.223141] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 45.223145] RBP: 00000000004bf970 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 45.223147] R10: 000000000000000e R11: 0000000000000246 R12: 0000000000000001 [ 45.223151] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 45.224439] Kernel Offset: disabled [ 45.811519] Rebooting in 86400 seconds..