[ 47.836457] audit: type=1800 audit(1581195874.816:30): pid=7994 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 OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 52.506366] kauditd_printk_skb: 4 callbacks suppressed [ 52.506381] audit: type=1400 audit(1581195879.526:35): avc: denied { map } for pid=8170 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 '10.128.1.2' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program [ 64.457441] audit: type=1400 audit(1581195891.486:36): avc: denied { map } for pid=8182 comm="syz-executor345" path="/root/syz-executor345452539" 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 [ 64.522167] ================================================================== [ 64.522222] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 64.522234] Write of size 8 at addr ffff888083e3e748 by task syz-executor345/8189 [ 64.522237] [ 64.522253] CPU: 0 PID: 8189 Comm: syz-executor345 Not tainted 4.19.102-syzkaller #0 [ 64.522261] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.522266] Call Trace: [ 64.522286] dump_stack+0x197/0x210 [ 64.522303] ? con_shutdown+0x85/0x90 [ 64.522324] print_address_description.cold+0x7c/0x20d [ 64.522341] ? con_shutdown+0x85/0x90 [ 64.522355] kasan_report.cold+0x8c/0x2ba [ 64.522370] ? set_palette+0x1c0/0x1c0 [ 64.522389] __asan_report_store8_noabort+0x17/0x20 [ 64.522404] con_shutdown+0x85/0x90 [ 64.522419] release_tty+0xe4/0x4d0 [ 64.522436] tty_release_struct+0x3c/0x50 [ 64.522451] tty_release+0xbcb/0xe90 [ 64.522475] ? tty_release_struct+0x50/0x50 [ 64.522492] __fput+0x2dd/0x8b0 [ 64.522516] ____fput+0x16/0x20 [ 64.522539] task_work_run+0x145/0x1c0 [ 64.522559] do_exit+0xc1f/0x30d0 [ 64.522582] ? mm_update_next_owner+0x660/0x660 [ 64.522598] ? up_read+0x1a/0x110 [ 64.522612] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 64.522628] ? __do_page_fault+0x484/0xe90 [ 64.522651] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 64.522666] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 64.522684] do_group_exit+0x135/0x370 [ 64.522702] __x64_sys_exit_group+0x44/0x50 [ 64.522717] do_syscall_64+0xfd/0x620 [ 64.522737] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.522750] RIP: 0033:0x43ff38 [ 64.522765] 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 [ 64.522773] RSP: 002b:00007ffd94f8f8a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 64.522787] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 64.522794] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 64.522803] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 64.522811] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 64.522820] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 64.522840] [ 64.522847] Allocated by task 8189: [ 64.522860] save_stack+0x45/0xd0 [ 64.522873] kasan_kmalloc+0xce/0xf0 [ 64.522885] kmem_cache_alloc_trace+0x152/0x760 [ 64.522897] vc_allocate+0x1f5/0x760 [ 64.522910] con_install+0x52/0x410 [ 64.522921] tty_init_dev+0xf7/0x460 [ 64.522933] tty_open+0x4bf/0xb70 [ 64.522944] chrdev_open+0x245/0x6b0 [ 64.522955] do_dentry_open+0x4c3/0x1210 [ 64.522965] vfs_open+0xa0/0xd0 [ 64.522979] path_openat+0x10d8/0x44a0 [ 64.522989] do_filp_open+0x1a1/0x280 [ 64.523000] do_sys_open+0x3fe/0x550 [ 64.523011] __x64_sys_open+0x7e/0xc0 [ 64.523024] do_syscall_64+0xfd/0x620 [ 64.523038] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.523041] [ 64.523047] Freed by task 8194: [ 64.523059] save_stack+0x45/0xd0 [ 64.523071] __kasan_slab_free+0x102/0x150 [ 64.523083] kasan_slab_free+0xe/0x10 [ 64.523094] kfree+0xcf/0x220 [ 64.523107] vt_disallocate_all+0x2bd/0x3e0 [ 64.523121] vt_ioctl+0xc38/0x2530 [ 64.523133] tty_ioctl+0x7f3/0x1510 [ 64.523145] do_vfs_ioctl+0xd5f/0x1380 [ 64.523156] ksys_ioctl+0xab/0xd0 [ 64.523168] __x64_sys_ioctl+0x73/0xb0 [ 64.523182] do_syscall_64+0xfd/0x620 [ 64.523197] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.523200] [ 64.523217] The buggy address belongs to the object at ffff888083e3e640 [ 64.523217] which belongs to the cache kmalloc-2048 of size 2048 [ 64.523229] The buggy address is located 264 bytes inside of [ 64.523229] 2048-byte region [ffff888083e3e640, ffff888083e3ee40) [ 64.523233] The buggy address belongs to the page: [ 64.523246] page:ffffea00020f8f80 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 [ 64.523267] flags: 0xfffe0000008100(slab|head) [ 64.523289] raw: 00fffe0000008100 ffffea000215d808 ffffea00020fc988 ffff88812c31cc40 [ 64.523307] raw: 0000000000000000 ffff888083e3e640 0000000100000003 0000000000000000 [ 64.523312] page dumped because: kasan: bad access detected [ 64.523316] [ 64.523320] Memory state around the buggy address: [ 64.523329] ffff888083e3e600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 64.523338] ffff888083e3e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.523347] >ffff888083e3e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.523352] ^ [ 64.523361] ffff888083e3e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.523370] ffff888083e3e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.523375] ================================================================== [ 64.523385] Disabling lock debugging due to kernel taint [ 64.523393] Kernel panic - not syncing: panic_on_warn set ... [ 64.523393] [ 64.523406] CPU: 0 PID: 8189 Comm: syz-executor345 Tainted: G B 4.19.102-syzkaller #0 [ 64.523413] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.523416] Call Trace: [ 64.523432] dump_stack+0x197/0x210 [ 64.523447] ? con_shutdown+0x85/0x90 [ 64.523462] panic+0x26a/0x50e [ 64.523477] ? __warn_printk+0xf3/0xf3 [ 64.523493] ? lock_downgrade+0x880/0x880 [ 64.523507] ? trace_hardirqs_on+0x67/0x220 [ 64.523526] ? trace_hardirqs_on+0x5e/0x220 [ 64.523542] ? con_shutdown+0x85/0x90 [ 64.523558] kasan_end_report+0x47/0x4f [ 64.523572] kasan_report.cold+0xa9/0x2ba [ 64.523586] ? set_palette+0x1c0/0x1c0 [ 64.523603] __asan_report_store8_noabort+0x17/0x20 [ 64.523616] con_shutdown+0x85/0x90 [ 64.523628] release_tty+0xe4/0x4d0 [ 64.523642] tty_release_struct+0x3c/0x50 [ 64.523656] tty_release+0xbcb/0xe90 [ 64.523674] ? tty_release_struct+0x50/0x50 [ 64.523693] __fput+0x2dd/0x8b0 [ 64.523715] ____fput+0x16/0x20 [ 64.523734] task_work_run+0x145/0x1c0 [ 64.523757] do_exit+0xc1f/0x30d0 [ 64.523782] ? mm_update_next_owner+0x660/0x660 [ 64.523797] ? up_read+0x1a/0x110 [ 64.523809] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 64.523822] ? __do_page_fault+0x484/0xe90 [ 64.523840] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 64.523855] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 64.523874] do_group_exit+0x135/0x370 [ 64.523889] __x64_sys_exit_group+0x44/0x50 [ 64.523904] do_syscall_64+0xfd/0x620 [ 64.523921] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.523930] RIP: 0033:0x43ff38 [ 64.523943] 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 [ 64.523951] RSP: 002b:00007ffd94f8f8a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 64.523963] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 64.523970] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 64.523978] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 64.523986] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 64.523994] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 64.525754] Kernel Offset: disabled [ 65.232013] Rebooting in 86400 seconds..