[ 41.605377] audit: type=1800 audit(1581261669.135:32): pid=7850 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2450 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 47.055075] kauditd_printk_skb: 2 callbacks suppressed [ 47.055090] audit: type=1400 audit(1581261674.655:35): avc: denied { map } for pid=8025 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 Warning: Permanently added '10.128.0.2' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program [ 53.768468] audit: type=1400 audit(1581261681.365:36): avc: denied { map } for pid=8037 comm="syz-executor105" path="/root/syz-executor105444485" 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 [ 53.828136] ================================================================== [ 53.828175] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 53.828187] Write of size 8 at addr ffff88809038d688 by task syz-executor105/8046 [ 53.828190] [ 53.828204] CPU: 0 PID: 8046 Comm: syz-executor105 Not tainted 4.19.102-syzkaller #0 [ 53.828212] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.828217] Call Trace: [ 53.828234] dump_stack+0x197/0x210 [ 53.828253] ? con_shutdown+0x85/0x90 [ 53.828271] print_address_description.cold+0x7c/0x20d [ 53.828287] ? con_shutdown+0x85/0x90 [ 53.828303] kasan_report.cold+0x8c/0x2ba [ 53.828319] ? set_palette+0x1c0/0x1c0 [ 53.828338] __asan_report_store8_noabort+0x17/0x20 [ 53.828351] con_shutdown+0x85/0x90 [ 53.828366] release_tty+0xe4/0x4d0 [ 53.828382] tty_release_struct+0x3c/0x50 [ 53.828398] tty_release+0xbcb/0xe90 [ 53.828420] ? tty_release_struct+0x50/0x50 [ 53.828435] __fput+0x2dd/0x8b0 [ 53.828456] ____fput+0x16/0x20 [ 53.828470] task_work_run+0x145/0x1c0 [ 53.828496] do_exit+0xc1f/0x30d0 [ 53.828514] ? mm_update_next_owner+0x660/0x660 [ 53.828526] ? up_read+0x1a/0x110 [ 53.828537] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 53.828549] ? __do_page_fault+0x484/0xe90 [ 53.828566] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.828577] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.828590] do_group_exit+0x135/0x370 [ 53.828605] __x64_sys_exit_group+0x44/0x50 [ 53.828617] do_syscall_64+0xfd/0x620 [ 53.828633] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.828642] RIP: 0033:0x43ff38 [ 53.828653] Code: Bad RIP value. [ 53.828659] RSP: 002b:00007ffdc0bb21f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 53.828670] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 53.828676] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 53.828683] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 53.828689] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 53.828695] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 53.828709] [ 53.828715] Allocated by task 8046: [ 53.828727] save_stack+0x45/0xd0 [ 53.828739] kasan_kmalloc+0xce/0xf0 [ 53.828752] kmem_cache_alloc_trace+0x152/0x760 [ 53.828769] vc_allocate+0x1f5/0x760 [ 53.828782] con_install+0x52/0x410 [ 53.828793] tty_init_dev+0xf7/0x460 [ 53.828806] tty_open+0x4bf/0xb70 [ 53.828817] chrdev_open+0x245/0x6b0 [ 53.828828] do_dentry_open+0x4c3/0x1210 [ 53.828839] vfs_open+0xa0/0xd0 [ 53.828853] path_openat+0x10d8/0x44a0 [ 53.828864] do_filp_open+0x1a1/0x280 [ 53.828876] do_sys_open+0x3fe/0x550 [ 53.828887] __x64_sys_open+0x7e/0xc0 [ 53.828902] do_syscall_64+0xfd/0x620 [ 53.828916] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.828920] [ 53.828926] Freed by task 8047: [ 53.828939] save_stack+0x45/0xd0 [ 53.828948] __kasan_slab_free+0x102/0x150 [ 53.828960] kasan_slab_free+0xe/0x10 [ 53.828969] kfree+0xcf/0x220 [ 53.828982] vt_disallocate_all+0x2bd/0x3e0 [ 53.828994] vt_ioctl+0xc38/0x2530 [ 53.829005] tty_ioctl+0x7f3/0x1510 [ 53.829017] do_vfs_ioctl+0xd5f/0x1380 [ 53.829028] ksys_ioctl+0xab/0xd0 [ 53.829040] __x64_sys_ioctl+0x73/0xb0 [ 53.829052] do_syscall_64+0xfd/0x620 [ 53.829065] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.829069] [ 53.829079] The buggy address belongs to the object at ffff88809038d580 [ 53.829079] which belongs to the cache kmalloc-2048 of size 2048 [ 53.829091] The buggy address is located 264 bytes inside of [ 53.829091] 2048-byte region [ffff88809038d580, ffff88809038dd80) [ 53.829096] The buggy address belongs to the page: [ 53.829107] page:ffffea000240e300 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 [ 53.829120] flags: 0xfffe0000008100(slab|head) [ 53.829138] raw: 00fffe0000008100 ffffea0001f93308 ffffea000231a108 ffff88812c31cc40 [ 53.829154] raw: 0000000000000000 ffff88809038c480 0000000100000003 0000000000000000 [ 53.829160] page dumped because: kasan: bad access detected [ 53.829163] [ 53.829168] Memory state around the buggy address: [ 53.829178] ffff88809038d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.829189] ffff88809038d600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.829199] >ffff88809038d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.829204] ^ [ 53.829214] ffff88809038d700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.829225] ffff88809038d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.829231] ================================================================== [ 53.829236] Disabling lock debugging due to kernel taint [ 53.829282] Kernel panic - not syncing: panic_on_warn set ... [ 53.829282] [ 53.829297] CPU: 0 PID: 8046 Comm: syz-executor105 Tainted: G B 4.19.102-syzkaller #0 [ 53.829304] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.829307] Call Trace: [ 53.829322] dump_stack+0x197/0x210 [ 53.829338] ? con_shutdown+0x85/0x90 [ 53.829351] panic+0x26a/0x50e [ 53.829365] ? __warn_printk+0xf3/0xf3 [ 53.829380] ? con_shutdown+0x85/0x90 [ 53.829391] ? preempt_schedule+0x4b/0x60 [ 53.829406] ? ___preempt_schedule+0x16/0x18 [ 53.829418] ? trace_hardirqs_on+0x5e/0x220 [ 53.829432] ? con_shutdown+0x85/0x90 [ 53.829445] kasan_end_report+0x47/0x4f [ 53.829458] kasan_report.cold+0xa9/0x2ba [ 53.829471] ? set_palette+0x1c0/0x1c0 [ 53.829486] __asan_report_store8_noabort+0x17/0x20 [ 53.829498] con_shutdown+0x85/0x90 [ 53.829510] release_tty+0xe4/0x4d0 [ 53.829524] tty_release_struct+0x3c/0x50 [ 53.829536] tty_release+0xbcb/0xe90 [ 53.829553] ? tty_release_struct+0x50/0x50 [ 53.829566] __fput+0x2dd/0x8b0 [ 53.829583] ____fput+0x16/0x20 [ 53.829594] task_work_run+0x145/0x1c0 [ 53.829608] do_exit+0xc1f/0x30d0 [ 53.829626] ? mm_update_next_owner+0x660/0x660 [ 53.829637] ? up_read+0x1a/0x110 [ 53.829650] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 53.829670] ? __do_page_fault+0x484/0xe90 [ 53.829688] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.829701] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.829716] do_group_exit+0x135/0x370 [ 53.829730] __x64_sys_exit_group+0x44/0x50 [ 53.829744] do_syscall_64+0xfd/0x620 [ 53.829767] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.829776] RIP: 0033:0x43ff38 [ 53.829788] Code: 00 00 be 3c 00 00 00 eb 19 66 0f 1f 84 00 00 00 00 00 48 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 21 f4 48 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 0f 1f 84 00 00 00 [ 53.829795] RSP: 002b:00007ffdc0bb21f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 53.829806] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 53.829813] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 53.829821] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 53.829827] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 53.829835] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 53.831492] Kernel Offset: disabled [ 54.506300] Rebooting in 86400 seconds..