[ 42.445316] audit: type=1800 audit(1578607671.926:30): pid=7919 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 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: [ 47.131911] kauditd_printk_skb: 4 callbacks suppressed [ 47.131927] audit: type=1400 audit(1578607676.636:35): avc: denied { map } for pid=8094 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 '10.128.0.67' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program [ 53.877300] audit: type=1400 audit(1578607683.376:36): avc: denied { map } for pid=8106 comm="syz-executor190" path="/root/syz-executor190718660" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program [ 53.973441] ================================================================== [ 53.973476] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 53.973487] Write of size 8 at addr ffff888092d92388 by task syz-executor190/8116 [ 53.973490] [ 53.973505] CPU: 0 PID: 8116 Comm: syz-executor190 Not tainted 4.19.94-syzkaller #0 [ 53.973513] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.973518] Call Trace: [ 53.973534] dump_stack+0x197/0x210 [ 53.973551] ? con_shutdown+0x85/0x90 [ 53.973569] print_address_description.cold+0x7c/0x20d [ 53.973585] ? con_shutdown+0x85/0x90 [ 53.973600] kasan_report.cold+0x8c/0x2ba [ 53.973616] ? set_palette+0x1c0/0x1c0 [ 53.973634] __asan_report_store8_noabort+0x17/0x20 [ 53.973650] con_shutdown+0x85/0x90 [ 53.973666] release_tty+0xe4/0x4d0 [ 53.973684] tty_release_struct+0x3c/0x50 [ 53.973701] tty_release+0xbcb/0xe90 [ 53.973725] ? tty_release_struct+0x50/0x50 [ 53.973741] __fput+0x2dd/0x8b0 [ 53.973764] ____fput+0x16/0x20 [ 53.973780] task_work_run+0x145/0x1c0 [ 53.973802] do_exit+0xc1f/0x30d0 [ 53.973827] ? mm_update_next_owner+0x660/0x660 [ 53.973842] ? up_read+0x1a/0x110 [ 53.973856] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 53.973870] ? __do_page_fault+0x484/0xe90 [ 53.973890] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.973904] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.973922] do_group_exit+0x135/0x370 [ 53.974066] __x64_sys_exit_group+0x44/0x50 [ 53.974097] do_syscall_64+0xfd/0x620 [ 53.974121] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.974135] RIP: 0033:0x43ff38 [ 53.974152] 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 [ 53.974162] RSP: 002b:00007ffc5bbc9138 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 53.974177] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 53.974187] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 53.974198] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 53.974208] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 53.974218] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 53.974238] [ 53.974246] Allocated by task 8116: [ 53.974262] save_stack+0x45/0xd0 [ 53.974277] kasan_kmalloc+0xce/0xf0 [ 53.974292] kmem_cache_alloc_trace+0x152/0x760 [ 53.974308] vc_allocate+0x1f5/0x760 [ 53.974324] con_install+0x52/0x410 [ 53.974339] tty_init_dev+0xf7/0x460 [ 53.974354] tty_open+0x4bf/0xb70 [ 53.974367] chrdev_open+0x245/0x6b0 [ 53.974381] do_dentry_open+0x4c3/0x1210 [ 53.974395] vfs_open+0xa0/0xd0 [ 53.974407] path_openat+0x10d7/0x45e0 [ 53.974421] do_filp_open+0x1a1/0x280 [ 53.974434] do_sys_open+0x3fe/0x550 [ 53.974447] __x64_sys_open+0x7e/0xc0 [ 53.974505] do_syscall_64+0xfd/0x620 [ 53.974529] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.974533] [ 53.974540] Freed by task 8117: [ 53.974554] save_stack+0x45/0xd0 [ 53.974568] __kasan_slab_free+0x102/0x150 [ 53.974582] kasan_slab_free+0xe/0x10 [ 53.974594] kfree+0xcf/0x220 [ 53.974607] vt_disallocate_all+0x2bd/0x3e0 [ 53.974621] vt_ioctl+0xc38/0x2530 [ 53.974635] tty_ioctl+0x7f3/0x1510 [ 53.974648] do_vfs_ioctl+0xd5f/0x1380 [ 53.974661] ksys_ioctl+0xab/0xd0 [ 53.974674] __x64_sys_ioctl+0x73/0xb0 [ 53.974689] do_syscall_64+0xfd/0x620 [ 53.974703] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.974707] [ 53.974719] The buggy address belongs to the object at ffff888092d92280 [ 53.974719] which belongs to the cache kmalloc-2048 of size 2048 [ 53.974732] The buggy address is located 264 bytes inside of [ 53.974732] 2048-byte region [ffff888092d92280, ffff888092d92a80) [ 53.974737] The buggy address belongs to the page: [ 53.974751] page:ffffea00024b6480 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 [ 53.974767] flags: 0xfffe0000008100(slab|head) [ 53.974788] raw: 00fffe0000008100 ffffea00029f1d88 ffffea000233ae08 ffff88812c31cc40 [ 53.974805] raw: 0000000000000000 ffff888092d92280 0000000100000003 0000000000000000 [ 53.974811] page dumped because: kasan: bad access detected [ 53.974815] [ 53.974820] Memory state around the buggy address: [ 53.974832] ffff888092d92280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.974843] ffff888092d92300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.974855] >ffff888092d92380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.974861] ^ [ 53.974872] ffff888092d92400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.974883] ffff888092d92480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 53.974934] ================================================================== [ 53.974940] Disabling lock debugging due to kernel taint [ 53.975072] Kernel panic - not syncing: panic_on_warn set ... [ 53.975072] [ 53.975088] CPU: 0 PID: 8116 Comm: syz-executor190 Tainted: G B 4.19.94-syzkaller #0 [ 53.975096] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.975100] Call Trace: [ 53.975117] dump_stack+0x197/0x210 [ 53.975135] ? con_shutdown+0x85/0x90 [ 53.975146] panic+0x26a/0x50e [ 53.975158] ? __warn_printk+0xf3/0xf3 [ 53.975174] ? con_shutdown+0x85/0x90 [ 53.975189] ? preempt_schedule+0x4b/0x60 [ 53.975203] ? ___preempt_schedule+0x16/0x18 [ 53.975219] ? trace_hardirqs_on+0x5e/0x220 [ 53.975237] ? con_shutdown+0x85/0x90 [ 53.975253] kasan_end_report+0x47/0x4f [ 53.975269] kasan_report.cold+0xa9/0x2ba [ 53.975284] ? set_palette+0x1c0/0x1c0 [ 53.975300] __asan_report_store8_noabort+0x17/0x20 [ 53.975312] con_shutdown+0x85/0x90 [ 53.975324] release_tty+0xe4/0x4d0 [ 53.975337] tty_release_struct+0x3c/0x50 [ 53.975348] tty_release+0xbcb/0xe90 [ 53.975364] ? tty_release_struct+0x50/0x50 [ 53.975375] __fput+0x2dd/0x8b0 [ 53.975390] ____fput+0x16/0x20 [ 53.975402] task_work_run+0x145/0x1c0 [ 53.975417] do_exit+0xc1f/0x30d0 [ 53.975434] ? mm_update_next_owner+0x660/0x660 [ 53.975447] ? up_read+0x1a/0x110 [ 53.975459] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 53.975472] ? __do_page_fault+0x484/0xe90 [ 53.975486] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.975498] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 53.975510] do_group_exit+0x135/0x370 [ 53.975523] __x64_sys_exit_group+0x44/0x50 [ 53.975535] do_syscall_64+0xfd/0x620 [ 53.975556] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.975564] RIP: 0033:0x43ff38 [ 53.975576] 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 [ 53.975585] RSP: 002b:00007ffc5bbc9138 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 53.975597] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 53.975603] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 53.975610] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 53.975617] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 53.975623] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 53.977360] Kernel Offset: disabled [ 54.690535] Rebooting in 86400 seconds..