[ 42.546678] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.45' (ECDSA) to the list of known hosts. [ 48.298815] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program [ 48.432295] audit: type=1400 audit(1584539584.412:36): avc: denied { map } for pid=7490 comm="syz-executor338" path="/root/syz-executor338798455" 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 [ 48.495966] ================================================================== [ 48.496003] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 48.496010] Write of size 8 at addr ffff888082e49488 by task syz-executor338/7498 [ 48.496012] [ 48.496020] CPU: 1 PID: 7498 Comm: syz-executor338 Not tainted 4.14.173-syzkaller #0 [ 48.496025] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.496028] Call Trace: [ 48.496041] dump_stack+0x13e/0x194 [ 48.496050] ? con_shutdown+0x7f/0x90 [ 48.496062] print_address_description.cold+0x7c/0x1e2 [ 48.496070] ? con_shutdown+0x7f/0x90 [ 48.496077] kasan_report.cold+0xa9/0x2ae [ 48.496085] ? set_palette+0x130/0x130 [ 48.496093] con_shutdown+0x7f/0x90 [ 48.496102] release_tty+0xb6/0x7a0 [ 48.496112] tty_release_struct+0x37/0x50 [ 48.496120] tty_release+0xaa6/0xd60 [ 48.496135] ? tty_release_struct+0x50/0x50 [ 48.496144] __fput+0x25f/0x790 [ 48.496159] task_work_run+0x113/0x190 [ 48.496172] do_exit+0x9f2/0x2b00 [ 48.496182] ? __do_page_fault+0x4e4/0xb40 [ 48.496191] ? mm_update_next_owner+0x5b0/0x5b0 [ 48.496200] ? lock_downgrade+0x6e0/0x6e0 [ 48.496214] do_group_exit+0x100/0x310 [ 48.496223] SyS_exit_group+0x19/0x20 [ 48.496230] ? do_group_exit+0x310/0x310 [ 48.496239] do_syscall_64+0x1d5/0x640 [ 48.496255] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.496262] RIP: 0033:0x43ff38 [ 48.496266] RSP: 002b:00007ffd2920ac08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 48.496275] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 48.496279] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 48.496283] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 48.496288] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 48.496292] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 48.496306] [ 48.496310] Allocated by task 7498: [ 48.496317] save_stack+0x32/0xa0 [ 48.496322] kasan_kmalloc+0xbf/0xe0 [ 48.496328] kmem_cache_alloc_trace+0x14d/0x7b0 [ 48.496335] vc_allocate+0x142/0x550 [ 48.496341] con_install+0x4f/0x3e0 [ 48.496348] tty_init_dev+0xe1/0x3a0 [ 48.496354] tty_open+0x410/0x9c0 [ 48.496360] chrdev_open+0x1fc/0x540 [ 48.496368] do_dentry_open+0x732/0xe90 [ 48.496374] vfs_open+0x105/0x220 [ 48.496381] path_openat+0x8ca/0x3c50 [ 48.496387] do_filp_open+0x18e/0x250 [ 48.496393] do_sys_open+0x29d/0x3f0 [ 48.496399] do_syscall_64+0x1d5/0x640 [ 48.496406] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.496408] [ 48.496411] Freed by task 7497: [ 48.496417] save_stack+0x32/0xa0 [ 48.496423] kasan_slab_free+0x75/0xc0 [ 48.496427] kfree+0xcb/0x260 [ 48.496433] vt_disallocate_all+0x25c/0x340 [ 48.496439] vt_ioctl+0x6e3/0x1f00 [ 48.496445] tty_ioctl+0x6c5/0x1220 [ 48.496483] do_vfs_ioctl+0x75a/0xfe0 [ 48.496489] SyS_ioctl+0x7f/0xb0 [ 48.496495] do_syscall_64+0x1d5/0x640 [ 48.496502] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.496504] [ 48.496510] The buggy address belongs to the object at ffff888082e49380 [ 48.496510] which belongs to the cache kmalloc-2048 of size 2048 [ 48.496514] The buggy address is located 264 bytes inside of [ 48.496514] 2048-byte region [ffff888082e49380, ffff888082e49b80) [ 48.496517] The buggy address belongs to the page: [ 48.496522] page:ffffea00020b9200 count:1 mapcount:0 mapping:ffff888082e48280 index:0x0 compound_mapcount: 0 [ 48.496532] flags: 0xfffe0000008100(slab|head) [ 48.496542] raw: 00fffe0000008100 ffff888082e48280 0000000000000000 0000000100000003 [ 48.496549] raw: ffffea00024c7b20 ffffea000219b320 ffff88812fe56c40 0000000000000000 [ 48.496552] page dumped because: kasan: bad access detected [ 48.496554] [ 48.496556] Memory state around the buggy address: [ 48.496562] ffff888082e49380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.496567] ffff888082e49400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.496572] >ffff888082e49480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.496574] ^ [ 48.496579] ffff888082e49500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.496585] ffff888082e49580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.496588] ================================================================== [ 48.496594] Disabling lock debugging due to kernel taint [ 48.496598] Kernel panic - not syncing: panic_on_warn set ... [ 48.496598] [ 48.496605] CPU: 1 PID: 7498 Comm: syz-executor338 Tainted: G B 4.14.173-syzkaller #0 [ 48.496609] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.496611] Call Trace: [ 48.496619] dump_stack+0x13e/0x194 [ 48.496626] panic+0x1f9/0x42d [ 48.496632] ? add_taint.cold+0x16/0x16 [ 48.496640] ? lock_downgrade+0x6e0/0x6e0 [ 48.496647] ? con_shutdown+0x7f/0x90 [ 48.496652] kasan_end_report+0x43/0x49 [ 48.496658] kasan_report.cold+0x12f/0x2ae [ 48.496665] ? set_palette+0x130/0x130 [ 48.496671] con_shutdown+0x7f/0x90 [ 48.496678] release_tty+0xb6/0x7a0 [ 48.496686] tty_release_struct+0x37/0x50 [ 48.496692] tty_release+0xaa6/0xd60 [ 48.496701] ? tty_release_struct+0x50/0x50 [ 48.496707] __fput+0x25f/0x790 [ 48.496717] task_work_run+0x113/0x190 [ 48.496725] do_exit+0x9f2/0x2b00 [ 48.496731] ? __do_page_fault+0x4e4/0xb40 [ 48.496738] ? mm_update_next_owner+0x5b0/0x5b0 [ 48.496745] ? lock_downgrade+0x6e0/0x6e0 [ 48.496756] do_group_exit+0x100/0x310 [ 48.496763] SyS_exit_group+0x19/0x20 [ 48.496768] ? do_group_exit+0x310/0x310 [ 48.496775] do_syscall_64+0x1d5/0x640 [ 48.496784] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.496789] RIP: 0033:0x43ff38 [ 48.496792] RSP: 002b:00007ffd2920ac08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 48.496799] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 48.496802] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 48.496806] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 48.496809] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 48.496812] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 48.498321] Kernel Offset: disabled