[ 44.074297] audit: type=1800 audit(1582816946.923:30): pid=7941 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: [ 48.757678] kauditd_printk_skb: 4 callbacks suppressed [ 48.757691] audit: type=1400 audit(1582816951.643:35): avc: denied { map } for pid=8114 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 '10.128.10.59' (ECDSA) to the list of known hosts. executing program executing program executing program executing program [ 61.124715] audit: type=1400 audit(1582816964.013:36): avc: denied { map } for pid=8126 comm="syz-executor855" path="/root/syz-executor855807080" 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 [ 61.170735] ================================================================== [ 61.170775] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 61.170786] Write of size 8 at addr ffff88808d6781c8 by task syz-executor855/8134 [ 61.170789] [ 61.170802] CPU: 1 PID: 8134 Comm: syz-executor855 Not tainted 4.19.106-syzkaller #0 [ 61.170809] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.170814] Call Trace: [ 61.170830] dump_stack+0x188/0x20d [ 61.170845] ? con_shutdown+0x7f/0x90 [ 61.170861] print_address_description.cold+0x7c/0x212 [ 61.170875] ? con_shutdown+0x7f/0x90 [ 61.170887] kasan_report.cold+0x88/0x2b9 [ 61.170901] ? set_palette+0x1b0/0x1b0 [ 61.170914] con_shutdown+0x7f/0x90 [ 61.170927] release_tty+0xda/0x4c0 [ 61.170941] tty_release_struct+0x37/0x50 [ 61.170954] tty_release+0xbc7/0xe90 [ 61.170971] ? tty_release_struct+0x50/0x50 [ 61.170985] __fput+0x2cd/0x890 [ 61.171003] task_work_run+0x13f/0x1b0 [ 61.171021] do_exit+0xbcd/0x2f30 [ 61.171043] ? mm_update_next_owner+0x650/0x650 [ 61.171059] ? up_read+0x17/0x110 [ 61.171072] ? __do_page_fault+0x44e/0xdd0 [ 61.171091] do_group_exit+0x125/0x350 [ 61.171115] __x64_sys_exit_group+0x3a/0x50 [ 61.171129] do_syscall_64+0xf9/0x620 [ 61.171147] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 61.171157] RIP: 0033:0x43ff38 [ 61.171170] 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 [ 61.171177] RSP: 002b:00007fff5bbaf038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 61.171189] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 61.171196] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 61.171204] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 61.171211] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 61.171218] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 61.171236] [ 61.171243] Allocated by task 8134: [ 61.171254] kasan_kmalloc+0xbf/0xe0 [ 61.171271] kmem_cache_alloc_trace+0x14d/0x7a0 [ 61.171281] vc_allocate+0x1db/0x6d0 [ 61.171292] con_install+0x4f/0x400 [ 61.171302] tty_init_dev+0xee/0x450 [ 61.171311] tty_open+0x4b0/0xb00 [ 61.171320] chrdev_open+0x219/0x5c0 [ 61.171330] do_dentry_open+0x4a8/0x1160 [ 61.171342] path_openat+0x1031/0x4200 [ 61.171354] do_filp_open+0x1a1/0x280 [ 61.171364] do_sys_open+0x3c0/0x500 [ 61.171375] do_syscall_64+0xf9/0x620 [ 61.171386] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 61.171389] [ 61.171394] Freed by task 8136: [ 61.171404] __kasan_slab_free+0xf7/0x140 [ 61.171413] kfree+0xce/0x220 [ 61.171426] vt_disallocate_all+0x293/0x3b0 [ 61.171437] vt_ioctl+0xb79/0x2320 [ 61.171446] tty_ioctl+0x7a1/0x1420 [ 61.171456] do_vfs_ioctl+0xcda/0x12e0 [ 61.171466] ksys_ioctl+0x9b/0xc0 [ 61.171476] __x64_sys_ioctl+0x6f/0xb0 [ 61.171487] do_syscall_64+0xf9/0x620 [ 61.171498] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 61.171502] [ 61.171511] The buggy address belongs to the object at ffff88808d6780c0 [ 61.171511] which belongs to the cache kmalloc-2048 of size 2048 [ 61.171521] The buggy address is located 264 bytes inside of [ 61.171521] 2048-byte region [ffff88808d6780c0, ffff88808d6788c0) [ 61.171525] The buggy address belongs to the page: [ 61.171536] page:ffffea0002359e00 count:1 mapcount:0 mapping:ffff88812c3dcc40 index:0x0 compound_mapcount: 0 [ 61.171548] flags: 0xfffe0000008100(slab|head) [ 61.171565] raw: 00fffe0000008100 ffffea00025c3308 ffffea000255b288 ffff88812c3dcc40 [ 61.171579] raw: 0000000000000000 ffff88808d6780c0 0000000100000003 0000000000000000 [ 61.171584] page dumped because: kasan: bad access detected [ 61.171588] [ 61.171591] Memory state around the buggy address: [ 61.171600] ffff88808d678080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 61.171609] ffff88808d678100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.171617] >ffff88808d678180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.171622] ^ [ 61.171630] ffff88808d678200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.171639] ffff88808d678280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.171643] ================================================================== [ 61.171647] Disabling lock debugging due to kernel taint [ 61.171750] Kernel panic - not syncing: panic_on_warn set ... [ 61.171750] [ 61.171763] CPU: 1 PID: 8134 Comm: syz-executor855 Tainted: G B 4.19.106-syzkaller #0 [ 61.171769] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.171772] Call Trace: [ 61.171786] dump_stack+0x188/0x20d [ 61.171800] panic+0x26a/0x50e [ 61.171813] ? __warn_printk+0xf3/0xf3 [ 61.171828] ? preempt_schedule_common+0x4a/0xc0 [ 61.171840] ? con_shutdown+0x7f/0x90 [ 61.171851] ? ___preempt_schedule+0x16/0x18 [ 61.171863] ? trace_hardirqs_on+0x55/0x210 [ 61.171875] ? con_shutdown+0x7f/0x90 [ 61.171888] kasan_end_report+0x43/0x49 [ 61.171899] kasan_report.cold+0xa4/0x2b9 [ 61.171910] ? set_palette+0x1b0/0x1b0 [ 61.171920] con_shutdown+0x7f/0x90 [ 61.171932] release_tty+0xda/0x4c0 [ 61.171944] tty_release_struct+0x37/0x50 [ 61.171955] tty_release+0xbc7/0xe90 [ 61.171969] ? tty_release_struct+0x50/0x50 [ 61.171980] __fput+0x2cd/0x890 [ 61.171994] task_work_run+0x13f/0x1b0 [ 61.172007] do_exit+0xbcd/0x2f30 [ 61.172023] ? mm_update_next_owner+0x650/0x650 [ 61.172037] ? up_read+0x17/0x110 [ 61.172049] ? __do_page_fault+0x44e/0xdd0 [ 61.172062] do_group_exit+0x125/0x350 [ 61.172075] __x64_sys_exit_group+0x3a/0x50 [ 61.172087] do_syscall_64+0xf9/0x620 [ 61.172108] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 61.172117] RIP: 0033:0x43ff38 [ 61.172129] 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 [ 61.172135] RSP: 002b:00007fff5bbaf038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 61.172146] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 61.172152] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 61.172159] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 61.172165] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 61.172172] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 61.173365] Kernel Offset: disabled [ 61.805255] Rebooting in 86400 seconds..