[ 47.760064] audit: type=1800 audit(1585183015.674:30): pid=8158 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: [ 53.979150] kauditd_printk_skb: 4 callbacks suppressed [ 53.979163] audit: type=1400 audit(1585183021.924:35): avc: denied { map } for pid=8331 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 '10.128.0.153' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 64.874847] audit: type=1400 audit(1585183032.824:36): avc: denied { map } for pid=8343 comm="syz-executor606" path="/root/syz-executor606850914" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 64.973223] ================================================================== [ 64.973262] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 64.973273] Write of size 8 at addr ffff88808c6d6f08 by task syz-executor606/8353 [ 64.973277] [ 64.973290] CPU: 0 PID: 8353 Comm: syz-executor606 Not tainted 4.19.113-syzkaller #0 [ 64.973297] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.973302] Call Trace: [ 64.973317] dump_stack+0x188/0x20d [ 64.973346] ? con_shutdown+0x7f/0x90 [ 64.973363] print_address_description.cold+0x7c/0x212 [ 64.973377] ? con_shutdown+0x7f/0x90 [ 64.973390] kasan_report.cold+0x88/0x2b9 [ 64.973404] ? set_palette+0x1b0/0x1b0 [ 64.973417] con_shutdown+0x7f/0x90 [ 64.973431] release_tty+0xda/0x4c0 [ 64.973446] tty_release_struct+0x37/0x50 [ 64.973459] tty_release+0xbc7/0xe90 [ 64.973479] ? tty_release_struct+0x50/0x50 [ 64.973508] __fput+0x2cd/0x890 [ 64.973526] task_work_run+0x13f/0x1b0 [ 64.973544] do_exit+0xbcd/0x2f30 [ 64.973564] ? mm_update_next_owner+0x650/0x650 [ 64.973582] ? up_read+0x17/0x110 [ 64.973595] ? __do_page_fault+0x44e/0xdd0 [ 64.973613] do_group_exit+0x125/0x350 [ 64.973629] __x64_sys_exit_group+0x3a/0x50 [ 64.973643] do_syscall_64+0xf9/0x620 [ 64.973660] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.973670] RIP: 0033:0x43ff38 [ 64.973682] Code: Bad RIP value. [ 64.973688] RSP: 002b:00007ffcb7e81dc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 64.973701] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 64.973723] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 64.973730] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 64.973737] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 64.973745] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 64.973763] [ 64.973769] Allocated by task 8353: [ 64.973782] kasan_kmalloc+0xbf/0xe0 [ 64.973792] kmem_cache_alloc_trace+0x14d/0x7a0 [ 64.973803] vc_allocate+0x1db/0x6d0 [ 64.973814] con_install+0x4f/0x400 [ 64.973824] tty_init_dev+0xee/0x450 [ 64.973835] tty_open+0x4b0/0xb00 [ 64.973845] chrdev_open+0x219/0x5c0 [ 64.973855] do_dentry_open+0x4a8/0x1160 [ 64.973867] path_openat+0x1031/0x4200 [ 64.973876] do_filp_open+0x1a1/0x280 [ 64.973886] do_sys_open+0x3c0/0x500 [ 64.973897] do_syscall_64+0xf9/0x620 [ 64.973909] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.973912] [ 64.973918] Freed by task 8354: [ 64.973930] __kasan_slab_free+0xf7/0x140 [ 64.973940] kfree+0xce/0x220 [ 64.973953] vt_disallocate_all+0x293/0x3b0 [ 64.973979] vt_ioctl+0xb79/0x2310 [ 64.973989] tty_ioctl+0x7a1/0x1420 [ 64.974014] do_vfs_ioctl+0xcda/0x12e0 [ 64.974038] ksys_ioctl+0x9b/0xc0 [ 64.974048] __x64_sys_ioctl+0x6f/0xb0 [ 64.974059] do_syscall_64+0xf9/0x620 [ 64.974071] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.974074] [ 64.974083] The buggy address belongs to the object at ffff88808c6d6e00 [ 64.974083] which belongs to the cache kmalloc-2048 of size 2048 [ 64.974093] The buggy address is located 264 bytes inside of [ 64.974093] 2048-byte region [ffff88808c6d6e00, ffff88808c6d7600) [ 64.974097] The buggy address belongs to the page: [ 64.974106] page:ffffea000231b580 count:1 mapcount:0 mapping:ffff88812c3dcc40 index:0x0 compound_mapcount: 0 [ 64.974119] flags: 0xfffe0000008100(slab|head) [ 64.974136] raw: 00fffe0000008100 ffffea0001f7b488 ffffea00027f6808 ffff88812c3dcc40 [ 64.974149] raw: 0000000000000000 ffff88808c6d6580 0000000100000003 0000000000000000 [ 64.974154] page dumped because: kasan: bad access detected [ 64.974157] [ 64.974160] Memory state around the buggy address: [ 64.974174] ffff88808c6d6e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.974192] ffff88808c6d6e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.974202] >ffff88808c6d6f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.974207] ^ [ 64.974216] ffff88808c6d6f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.974225] ffff88808c6d7000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.974230] ================================================================== [ 64.974234] Disabling lock debugging due to kernel taint [ 64.974264] Kernel panic - not syncing: panic_on_warn set ... [ 64.974264] [ 64.974277] CPU: 0 PID: 8353 Comm: syz-executor606 Tainted: G B 4.19.113-syzkaller #0 [ 64.974283] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.974301] Call Trace: [ 64.974315] dump_stack+0x188/0x20d [ 64.974330] panic+0x26a/0x50e [ 64.974343] ? __warn_printk+0xf3/0xf3 [ 64.974353] ? retint_kernel+0x2d/0x2d [ 64.974369] ? trace_hardirqs_on+0x55/0x210 [ 64.974383] ? con_shutdown+0x7f/0x90 [ 64.974395] kasan_end_report+0x43/0x49 [ 64.974407] kasan_report.cold+0xa4/0x2b9 [ 64.974419] ? set_palette+0x1b0/0x1b0 [ 64.974431] con_shutdown+0x7f/0x90 [ 64.974442] release_tty+0xda/0x4c0 [ 64.974455] tty_release_struct+0x37/0x50 [ 64.974467] tty_release+0xbc7/0xe90 [ 64.974482] ? tty_release_struct+0x50/0x50 [ 64.974508] __fput+0x2cd/0x890 [ 64.974537] task_work_run+0x13f/0x1b0 [ 64.974550] do_exit+0xbcd/0x2f30 [ 64.974582] ? mm_update_next_owner+0x650/0x650 [ 64.974594] ? up_read+0x17/0x110 [ 64.974606] ? __do_page_fault+0x44e/0xdd0 [ 64.974620] do_group_exit+0x125/0x350 [ 64.974633] __x64_sys_exit_group+0x3a/0x50 [ 64.974645] do_syscall_64+0xf9/0x620 [ 64.974658] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.974666] RIP: 0033:0x43ff38 [ 64.974674] Code: Bad RIP value. [ 64.974681] RSP: 002b:00007ffcb7e81dc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 64.974690] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 64.974697] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 64.974704] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 64.974710] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 64.974717] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 64.975757] Kernel Offset: disabled