[ 37.293420] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.107' (ECDSA) to the list of known hosts. [ 42.839469] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program [ 42.961317] audit: type=1400 audit(1581766362.817:36): avc: denied { map } for pid=7285 comm="syz-executor313" path="/root/syz-executor313180635" 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 [ 43.018918] ================================================================== [ 43.018948] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 43.018954] Write of size 8 at addr ffff8880a06fed48 by task syz-executor313/7293 [ 43.018957] [ 43.018965] CPU: 1 PID: 7293 Comm: syz-executor313 Not tainted 4.14.171-syzkaller #0 [ 43.018970] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.018973] Call Trace: [ 43.018984] dump_stack+0x142/0x197 [ 43.018995] ? con_shutdown+0x85/0x90 [ 43.019005] print_address_description.cold+0x7c/0x1dc [ 43.019014] ? con_shutdown+0x85/0x90 [ 43.019022] kasan_report.cold+0xa9/0x2af [ 43.019030] ? set_palette+0x140/0x140 [ 43.019040] __asan_report_store8_noabort+0x17/0x20 [ 43.019047] con_shutdown+0x85/0x90 [ 43.019056] release_tty+0xbf/0x7c0 [ 43.019066] tty_release_struct+0x3c/0x50 [ 43.019075] tty_release+0xaa3/0xd60 [ 43.019090] ? tty_release_struct+0x50/0x50 [ 43.019097] __fput+0x275/0x7a0 [ 43.019110] ____fput+0x16/0x20 [ 43.019120] task_work_run+0x114/0x190 [ 43.019133] do_exit+0xa1a/0x2cd0 [ 43.019147] ? mm_update_next_owner+0x5d0/0x5d0 [ 43.019160] ? up_read+0x1a/0x40 [ 43.019168] ? __do_page_fault+0x358/0xb80 [ 43.019178] do_group_exit+0x111/0x330 [ 43.019188] SyS_exit_group+0x1d/0x20 [ 43.019195] ? do_group_exit+0x330/0x330 [ 43.019204] do_syscall_64+0x1e8/0x640 [ 43.019211] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.019226] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.019232] RIP: 0033:0x43ff38 [ 43.019237] RSP: 002b:00007ffcb92f79e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 43.019246] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 43.019251] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 43.019255] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 43.019268] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 43.019273] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 43.019287] [ 43.019291] Allocated by task 7293: [ 43.019299] save_stack_trace+0x16/0x20 [ 43.019305] save_stack+0x45/0xd0 [ 43.019317] kasan_kmalloc+0xce/0xf0 [ 43.019322] kmem_cache_alloc_trace+0x152/0x790 [ 43.019330] vc_allocate+0x148/0x580 [ 43.019336] con_install+0x52/0x400 [ 43.019343] tty_init_dev+0xea/0x3a0 [ 43.019349] tty_open+0x414/0xa10 [ 43.019356] chrdev_open+0x207/0x590 [ 43.019363] do_dentry_open+0x73b/0xeb0 [ 43.019369] vfs_open+0x105/0x220 [ 43.019376] path_openat+0x917/0x3e50 [ 43.019383] do_filp_open+0x18e/0x250 [ 43.019389] do_sys_open+0x2c5/0x430 [ 43.019396] SyS_open+0x2d/0x40 [ 43.019402] do_syscall_64+0x1e8/0x640 [ 43.019409] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.019412] [ 43.019415] Freed by task 7294: [ 43.019422] save_stack_trace+0x16/0x20 [ 43.019427] save_stack+0x45/0xd0 [ 43.019434] kasan_slab_free+0x75/0xc0 [ 43.019439] kfree+0xcc/0x270 [ 43.019446] vt_disallocate_all+0x286/0x380 [ 43.019451] vt_ioctl+0x76b/0x2170 [ 43.019457] tty_ioctl+0x841/0x1320 [ 43.019464] do_vfs_ioctl+0x7ae/0x1060 [ 43.019470] SyS_ioctl+0x8f/0xc0 [ 43.019477] do_syscall_64+0x1e8/0x640 [ 43.019484] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.019486] [ 43.019492] The buggy address belongs to the object at ffff8880a06fec40 [ 43.019492] which belongs to the cache kmalloc-2048 of size 2048 [ 43.019498] The buggy address is located 264 bytes inside of [ 43.019498] 2048-byte region [ffff8880a06fec40, ffff8880a06ff440) [ 43.019501] The buggy address belongs to the page: [ 43.019507] page:ffffea000281bf80 count:1 mapcount:0 mapping:ffff8880a06fe3c0 index:0x0 compound_mapcount: 0 [ 43.019516] flags: 0xfffe0000008100(slab|head) [ 43.019527] raw: 00fffe0000008100 ffff8880a06fe3c0 0000000000000000 0000000100000003 [ 43.019535] raw: ffffea0002818d20 ffffea00027de020 ffff8880aa800c40 0000000000000000 [ 43.019538] page dumped because: kasan: bad access detected [ 43.019540] [ 43.019543] Memory state around the buggy address: [ 43.019549] ffff8880a06fec00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 43.019555] ffff8880a06fec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.019560] >ffff8880a06fed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.019564] ^ [ 43.019570] ffff8880a06fed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.019575] ffff8880a06fee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.019578] ================================================================== [ 43.019581] Disabling lock debugging due to kernel taint [ 43.019585] Kernel panic - not syncing: panic_on_warn set ... [ 43.019585] [ 43.019591] CPU: 1 PID: 7293 Comm: syz-executor313 Tainted: G B 4.14.171-syzkaller #0 [ 43.019595] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.019596] Call Trace: [ 43.019604] dump_stack+0x142/0x197 [ 43.019611] ? con_shutdown+0x85/0x90 [ 43.019616] panic+0x1f9/0x42d [ 43.019622] ? add_taint.cold+0x16/0x16 [ 43.019630] ? lock_downgrade+0x740/0x740 [ 43.019640] kasan_end_report+0x47/0x4f [ 43.019647] kasan_report.cold+0x130/0x2af [ 43.019654] ? set_palette+0x140/0x140 [ 43.019662] __asan_report_store8_noabort+0x17/0x20 [ 43.019668] con_shutdown+0x85/0x90 [ 43.019674] release_tty+0xbf/0x7c0 [ 43.019682] tty_release_struct+0x3c/0x50 [ 43.019689] tty_release+0xaa3/0xd60 [ 43.019699] ? tty_release_struct+0x50/0x50 [ 43.019704] __fput+0x275/0x7a0 [ 43.019714] ____fput+0x16/0x20 [ 43.019721] task_work_run+0x114/0x190 [ 43.019734] do_exit+0xa1a/0x2cd0 [ 43.019744] ? mm_update_next_owner+0x5d0/0x5d0 [ 43.019752] ? up_read+0x1a/0x40 [ 43.019757] ? __do_page_fault+0x358/0xb80 [ 43.019795] do_group_exit+0x111/0x330 [ 43.019809] SyS_exit_group+0x1d/0x20 [ 43.019813] ? do_group_exit+0x330/0x330 [ 43.019817] do_syscall_64+0x1e8/0x640 [ 43.019822] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.019830] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.019835] RIP: 0033:0x43ff38 [ 43.019839] RSP: 002b:00007ffcb92f79e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 43.019849] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 43.019852] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 43.019856] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 43.019859] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 43.019863] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 43.021511] Kernel Offset: disabled [ 43.644576] Rebooting in 86400 seconds..