[ 44.777535] audit: type=1800 audit(1582110523.400:30): pid=8005 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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: [ 49.676899] kauditd_printk_skb: 4 callbacks suppressed [ 49.676914] audit: type=1400 audit(1582110528.320:35): avc: denied { map } for pid=8181 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 '10.128.0.42' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program [ 57.493047] audit: type=1400 audit(1582110536.140:36): avc: denied { map } for pid=8193 comm="syz-executor682" path="/root/syz-executor682559777" 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 [ 57.563737] ================================================================== [ 57.563775] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 57.563788] Write of size 8 at addr ffff88808457e548 by task syz-executor682/8201 [ 57.563791] [ 57.563806] CPU: 0 PID: 8201 Comm: syz-executor682 Not tainted 4.19.104-syzkaller #0 [ 57.563815] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.563820] Call Trace: [ 57.563847] dump_stack+0x197/0x210 [ 57.563865] ? con_shutdown+0x85/0x90 [ 57.563884] print_address_description.cold+0x7c/0x20d [ 57.563901] ? con_shutdown+0x85/0x90 [ 57.563916] kasan_report.cold+0x8c/0x2ba [ 57.563932] ? set_palette+0x1c0/0x1c0 [ 57.563950] __asan_report_store8_noabort+0x17/0x20 [ 57.563965] con_shutdown+0x85/0x90 [ 57.563980] release_tty+0xe4/0x4d0 [ 57.563996] tty_release_struct+0x3c/0x50 [ 57.564009] tty_release+0xbcb/0xe90 [ 57.564031] ? tty_release_struct+0x50/0x50 [ 57.564046] __fput+0x2dd/0x8b0 [ 57.564068] ____fput+0x16/0x20 [ 57.564083] task_work_run+0x145/0x1c0 [ 57.564103] do_exit+0xc1f/0x30d0 [ 57.564129] ? mm_update_next_owner+0x660/0x660 [ 57.564143] ? up_read+0x1a/0x110 [ 57.564157] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 57.564171] ? __do_page_fault+0x484/0xe90 [ 57.564192] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.564214] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.564230] do_group_exit+0x135/0x370 [ 57.564247] __x64_sys_exit_group+0x44/0x50 [ 57.564262] do_syscall_64+0xfd/0x620 [ 57.564281] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.564292] RIP: 0033:0x43ff38 [ 57.564304] Code: Bad RIP value. [ 57.564310] RSP: 002b:00007ffc94649548 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 57.564321] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 57.564327] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 57.564334] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 57.564341] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 57.564347] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 57.564361] [ 57.564366] Allocated by task 8201: [ 57.564376] save_stack+0x45/0xd0 [ 57.564385] kasan_kmalloc+0xce/0xf0 [ 57.564394] kmem_cache_alloc_trace+0x152/0x760 [ 57.564404] vc_allocate+0x1f5/0x760 [ 57.564413] con_install+0x52/0x410 [ 57.564422] tty_init_dev+0xf7/0x460 [ 57.564431] tty_open+0x4bf/0xb70 [ 57.564439] chrdev_open+0x245/0x6b0 [ 57.564447] do_dentry_open+0x4c3/0x1210 [ 57.564459] vfs_open+0xa0/0xd0 [ 57.564471] path_openat+0x10d8/0x44a0 [ 57.564481] do_filp_open+0x1a1/0x280 [ 57.564489] do_sys_open+0x3fe/0x550 [ 57.564497] __x64_sys_open+0x7e/0xc0 [ 57.564507] do_syscall_64+0xfd/0x620 [ 57.564517] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.564520] [ 57.564524] Freed by task 8200: [ 57.564533] save_stack+0x45/0xd0 [ 57.564543] __kasan_slab_free+0x102/0x150 [ 57.564552] kasan_slab_free+0xe/0x10 [ 57.564560] kfree+0xcf/0x220 [ 57.564571] vt_disallocate_all+0x2bd/0x3e0 [ 57.564581] vt_ioctl+0xc38/0x2530 [ 57.564590] tty_ioctl+0x7f3/0x1510 [ 57.564598] do_vfs_ioctl+0xd5f/0x1380 [ 57.564606] ksys_ioctl+0xab/0xd0 [ 57.564615] __x64_sys_ioctl+0x73/0xb0 [ 57.564625] do_syscall_64+0xfd/0x620 [ 57.564635] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.564638] [ 57.564645] The buggy address belongs to the object at ffff88808457e440 [ 57.564645] which belongs to the cache kmalloc-2048 of size 2048 [ 57.564654] The buggy address is located 264 bytes inside of [ 57.564654] 2048-byte region [ffff88808457e440, ffff88808457ec40) [ 57.564657] The buggy address belongs to the page: [ 57.564666] page:ffffea0002115f80 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 [ 57.564677] flags: 0xfffe0000008100(slab|head) [ 57.564690] raw: 00fffe0000008100 ffffea00023fb208 ffffea00023b0888 ffff88812c31cc40 [ 57.564702] raw: 0000000000000000 ffff88808457e440 0000000100000003 0000000000000000 [ 57.564707] page dumped because: kasan: bad access detected [ 57.564710] [ 57.564715] Memory state around the buggy address: [ 57.564726] ffff88808457e400: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 57.564738] ffff88808457e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.564749] >ffff88808457e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.564754] ^ [ 57.564764] ffff88808457e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.564774] ffff88808457e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.564779] ================================================================== [ 57.564783] Disabling lock debugging due to kernel taint [ 57.564815] Kernel panic - not syncing: panic_on_warn set ... [ 57.564815] [ 57.564827] CPU: 0 PID: 8201 Comm: syz-executor682 Tainted: G B 4.19.104-syzkaller #0 [ 57.564842] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.564846] Call Trace: [ 57.564860] dump_stack+0x197/0x210 [ 57.564872] ? con_shutdown+0x85/0x90 [ 57.564884] panic+0x26a/0x50e [ 57.564898] ? __warn_printk+0xf3/0xf3 [ 57.564909] ? con_shutdown+0x85/0x90 [ 57.564926] ? trace_hardirqs_on+0x5e/0x220 [ 57.564937] ? trace_hardirqs_on+0x5e/0x220 [ 57.564952] ? con_shutdown+0x85/0x90 [ 57.564966] kasan_end_report+0x47/0x4f [ 57.564981] kasan_report.cold+0xa9/0x2ba [ 57.564994] ? set_palette+0x1c0/0x1c0 [ 57.565008] __asan_report_store8_noabort+0x17/0x20 [ 57.565019] con_shutdown+0x85/0x90 [ 57.565039] release_tty+0xe4/0x4d0 [ 57.565053] tty_release_struct+0x3c/0x50 [ 57.565065] tty_release+0xbcb/0xe90 [ 57.565083] ? tty_release_struct+0x50/0x50 [ 57.565095] __fput+0x2dd/0x8b0 [ 57.565112] ____fput+0x16/0x20 [ 57.565125] task_work_run+0x145/0x1c0 [ 57.565141] do_exit+0xc1f/0x30d0 [ 57.565156] ? mm_update_next_owner+0x660/0x660 [ 57.565166] ? up_read+0x1a/0x110 [ 57.565175] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 57.565185] ? __do_page_fault+0x484/0xe90 [ 57.565198] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.565208] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.565218] do_group_exit+0x135/0x370 [ 57.565229] __x64_sys_exit_group+0x44/0x50 [ 57.565240] do_syscall_64+0xfd/0x620 [ 57.565252] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.565258] RIP: 0033:0x43ff38 [ 57.565267] Code: Bad RIP value. [ 57.565272] RSP: 002b:00007ffc94649548 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 57.565281] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 57.565286] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 57.565292] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 57.565297] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 57.565303] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 57.566715] Kernel Offset: disabled