1G[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 38.502776] random: sshd: uninitialized urandom read (32 bytes read) [ 38.716032] audit: type=1400 audit(1581336021.018:35): avc: denied { map } for pid=7307 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 [ 38.767997] random: sshd: uninitialized urandom read (32 bytes read) [ 39.509749] random: sshd: uninitialized urandom read (32 bytes read) [ 53.099608] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.37' (ECDSA) to the list of known hosts. [ 58.685693] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.800901] audit: type=1400 audit(1581336041.108:36): avc: denied { map } for pid=7319 comm="syz-executor147" path="/root/syz-executor147991494" 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 [ 58.865960] ================================================================== [ 58.865990] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 58.865997] Write of size 8 at addr ffff88809b2dc9c8 by task syz-executor147/7334 [ 58.865999] [ 58.866009] CPU: 0 PID: 7334 Comm: syz-executor147 Not tainted 4.14.170-syzkaller #0 [ 58.866013] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 58.866016] Call Trace: [ 58.866028] dump_stack+0x142/0x197 [ 58.866038] ? con_shutdown+0x85/0x90 [ 58.866048] print_address_description.cold+0x7c/0x1dc [ 58.866058] ? con_shutdown+0x85/0x90 [ 58.866066] kasan_report.cold+0xa9/0x2af [ 58.866074] ? set_palette+0x140/0x140 [ 58.866084] __asan_report_store8_noabort+0x17/0x20 [ 58.866092] con_shutdown+0x85/0x90 [ 58.866101] release_tty+0xbf/0x7c0 [ 58.866112] tty_release_struct+0x3c/0x50 [ 58.866121] tty_release+0xaa3/0xd60 [ 58.866136] ? tty_release_struct+0x50/0x50 [ 58.866143] __fput+0x275/0x7a0 [ 58.866156] ____fput+0x16/0x20 [ 58.866167] task_work_run+0x114/0x190 [ 58.866181] do_exit+0xa1a/0x2cd0 [ 58.866195] ? mm_update_next_owner+0x5d0/0x5d0 [ 58.866207] ? up_read+0x1a/0x40 [ 58.866215] ? __do_page_fault+0x358/0xb80 [ 58.866225] do_group_exit+0x111/0x330 [ 58.866236] SyS_exit_group+0x1d/0x20 [ 58.866243] ? do_group_exit+0x330/0x330 [ 58.866251] do_syscall_64+0x1e8/0x640 [ 58.866259] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 58.866273] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 58.866280] RIP: 0033:0x43ff38 [ 58.866285] RSP: 002b:00007ffd91604128 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 58.866294] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 58.866299] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 58.866304] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 58.866308] R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000001 [ 58.866313] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 58.866327] [ 58.866331] Allocated by task 7334: [ 58.866346] save_stack_trace+0x16/0x20 [ 58.866353] save_stack+0x45/0xd0 [ 58.866359] kasan_kmalloc+0xce/0xf0 [ 58.866365] kmem_cache_alloc_trace+0x152/0x790 [ 58.866372] vc_allocate+0x148/0x580 [ 58.866378] con_install+0x52/0x400 [ 58.866385] tty_init_dev+0xea/0x3a0 [ 58.866392] tty_open+0x414/0xa10 [ 58.866398] chrdev_open+0x207/0x590 [ 58.866406] do_dentry_open+0x73b/0xeb0 [ 58.866413] vfs_open+0x105/0x220 [ 58.866419] path_openat+0x917/0x3e50 [ 58.866425] do_filp_open+0x18e/0x250 [ 58.866432] do_sys_open+0x2c5/0x430 [ 58.866438] SyS_open+0x2d/0x40 [ 58.866445] do_syscall_64+0x1e8/0x640 [ 58.866452] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 58.866455] [ 58.866458] Freed by task 7331: [ 58.866464] save_stack_trace+0x16/0x20 [ 58.866470] save_stack+0x45/0xd0 [ 58.866476] kasan_slab_free+0x75/0xc0 [ 58.866481] kfree+0xcc/0x270 [ 58.866487] vt_disallocate_all+0x286/0x380 [ 58.866493] vt_ioctl+0x76b/0x2170 [ 58.866499] tty_ioctl+0x841/0x1320 [ 58.866506] do_vfs_ioctl+0x7ae/0x1060 [ 58.866513] SyS_ioctl+0x8f/0xc0 [ 58.866519] do_syscall_64+0x1e8/0x640 [ 58.866526] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 58.866529] [ 58.866534] The buggy address belongs to the object at ffff88809b2dc8c0 [ 58.866534] which belongs to the cache kmalloc-2048 of size 2048 [ 58.866540] The buggy address is located 264 bytes inside of [ 58.866540] 2048-byte region [ffff88809b2dc8c0, ffff88809b2dd0c0) [ 58.866543] The buggy address belongs to the page: [ 58.866550] page:ffffea00026cb700 count:1 mapcount:0 mapping:ffff88809b2dc040 index:0x0 compound_mapcount: 0 [ 58.866560] flags: 0xfffe0000008100(slab|head) [ 58.866570] raw: 00fffe0000008100 ffff88809b2dc040 0000000000000000 0000000100000003 [ 58.866579] raw: ffffea0002585ca0 ffffea00026b55a0 ffff8880aa800c40 0000000000000000 [ 58.866582] page dumped because: kasan: bad access detected [ 58.866584] [ 58.866587] Memory state around the buggy address: [ 58.866594] ffff88809b2dc880: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 58.866600] ffff88809b2dc900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 58.866606] >ffff88809b2dc980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 58.866609] ^ [ 58.866615] ffff88809b2dca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 58.866620] ffff88809b2dca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 58.866623] ================================================================== [ 58.866626] Disabling lock debugging due to kernel taint [ 58.866630] Kernel panic - not syncing: panic_on_warn set ... [ 58.866630] [ 58.866637] CPU: 0 PID: 7334 Comm: syz-executor147 Tainted: G B 4.14.170-syzkaller #0 [ 58.866640] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 58.866642] Call Trace: [ 58.866650] dump_stack+0x142/0x197 [ 58.866658] ? con_shutdown+0x85/0x90 [ 58.866664] panic+0x1f9/0x42d [ 58.866670] ? add_taint.cold+0x16/0x16 [ 58.866678] ? lock_downgrade+0x740/0x740 [ 58.866687] kasan_end_report+0x47/0x4f [ 58.866694] kasan_report.cold+0x130/0x2af [ 58.866702] ? set_palette+0x140/0x140 [ 58.866715] __asan_report_store8_noabort+0x17/0x20 [ 58.866722] con_shutdown+0x85/0x90 [ 58.866729] release_tty+0xbf/0x7c0 [ 58.866737] tty_release_struct+0x3c/0x50 [ 58.866744] tty_release+0xaa3/0xd60 [ 58.866755] ? tty_release_struct+0x50/0x50 [ 58.866761] __fput+0x275/0x7a0 [ 58.866770] ____fput+0x16/0x20 [ 58.866777] task_work_run+0x114/0x190 [ 58.866784] do_exit+0xa1a/0x2cd0 [ 58.866794] ? mm_update_next_owner+0x5d0/0x5d0 [ 58.866801] ? up_read+0x1a/0x40 [ 58.866807] ? __do_page_fault+0x358/0xb80 [ 58.866814] do_group_exit+0x111/0x330 [ 58.866822] SyS_exit_group+0x1d/0x20 [ 58.866828] ? do_group_exit+0x330/0x330 [ 58.866835] do_syscall_64+0x1e8/0x640 [ 58.866841] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 58.866850] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 58.866854] RIP: 0033:0x43ff38 [ 58.866857] RSP: 002b:00007ffd91604128 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 58.866864] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 58.866868] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 58.866872] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 58.866875] R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000001 [ 58.866879] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 58.868374] Kernel Offset: disabled [ 59.492142] Rebooting in 86400 seconds..