ing file context[ 35.821737] audit: type=1800 audit(1584741193.415:34): pid=7329 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 37.412304] random: sshd: uninitialized urandom read (32 bytes read) [ 37.611880] audit: type=1400 audit(1584741195.235:35): avc: denied { map } for pid=7501 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 [ 37.696183] random: sshd: uninitialized urandom read (32 bytes read) [ 38.437049] random: sshd: uninitialized urandom read (32 bytes read) [ 42.352152] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.12' (ECDSA) to the list of known hosts. [ 47.948207] 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 executing program executing program executing program [ 48.073683] audit: type=1400 audit(1584741205.695:36): avc: denied { map } for pid=7513 comm="syz-executor261" path="/root/syz-executor261545403" 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 [ 48.159917] ================================================================== [ 48.159944] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 48.159949] Write of size 8 at addr ffff88808ada5388 by task syz-executor261/7532 [ 48.159951] [ 48.159957] CPU: 1 PID: 7532 Comm: syz-executor261 Not tainted 4.14.174-syzkaller #0 [ 48.159961] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.159963] Call Trace: [ 48.159973] dump_stack+0x13e/0x194 [ 48.159980] ? con_shutdown+0x7f/0x90 [ 48.159989] print_address_description.cold+0x7c/0x1e2 [ 48.159996] ? con_shutdown+0x7f/0x90 [ 48.160001] kasan_report.cold+0xa9/0x2ae [ 48.160013] ? set_palette+0x130/0x130 [ 48.160020] con_shutdown+0x7f/0x90 [ 48.160028] release_tty+0xb6/0x7a0 [ 48.160037] tty_release_struct+0x37/0x50 [ 48.160043] tty_release+0xaa6/0xd60 [ 48.160056] ? tty_release_struct+0x50/0x50 [ 48.160063] __fput+0x25f/0x790 [ 48.160077] task_work_run+0x113/0x190 [ 48.160088] do_exit+0x9f2/0x2b00 [ 48.160097] ? __do_page_fault+0x4e4/0xb40 [ 48.160106] ? mm_update_next_owner+0x5b0/0x5b0 [ 48.160116] ? lock_downgrade+0x6e0/0x6e0 [ 48.160128] do_group_exit+0x100/0x310 [ 48.160137] SyS_exit_group+0x19/0x20 [ 48.160143] ? do_group_exit+0x310/0x310 [ 48.160151] do_syscall_64+0x1d5/0x640 [ 48.160165] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.160172] RIP: 0033:0x43ff38 [ 48.160176] RSP: 002b:00007ffcb9bdf7b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 48.160184] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 48.160189] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 48.160193] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 48.160197] R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000001 [ 48.160201] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 48.160214] [ 48.160218] Allocated by task 7532: [ 48.160225] save_stack+0x32/0xa0 [ 48.160237] kasan_kmalloc+0xbf/0xe0 [ 48.160243] kmem_cache_alloc_trace+0x14d/0x7b0 [ 48.160249] vc_allocate+0x142/0x550 [ 48.160255] con_install+0x4f/0x3e0 [ 48.160261] tty_init_dev+0xe1/0x3a0 [ 48.160267] tty_open+0x410/0x9c0 [ 48.160273] chrdev_open+0x1fc/0x540 [ 48.160281] do_dentry_open+0x732/0xe90 [ 48.160287] vfs_open+0x105/0x220 [ 48.160294] path_openat+0x8ca/0x3c50 [ 48.160300] do_filp_open+0x18e/0x250 [ 48.160306] do_sys_open+0x29d/0x3f0 [ 48.160313] do_syscall_64+0x1d5/0x640 [ 48.160319] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.160322] [ 48.160325] Freed by task 7531: [ 48.160330] save_stack+0x32/0xa0 [ 48.160336] kasan_slab_free+0x75/0xc0 [ 48.160340] kfree+0xcb/0x260 [ 48.160345] vt_disallocate_all+0x25c/0x340 [ 48.160350] vt_ioctl+0x6e3/0x1f00 [ 48.160354] tty_ioctl+0x6c5/0x1220 [ 48.160360] do_vfs_ioctl+0x75a/0xfe0 [ 48.160366] SyS_ioctl+0x7f/0xb0 [ 48.160371] do_syscall_64+0x1d5/0x640 [ 48.160377] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.160379] [ 48.160385] The buggy address belongs to the object at ffff88808ada5280 [ 48.160385] which belongs to the cache kmalloc-2048 of size 2048 [ 48.160391] The buggy address is located 264 bytes inside of [ 48.160391] 2048-byte region [ffff88808ada5280, ffff88808ada5a80) [ 48.160394] The buggy address belongs to the page: [ 48.160399] page:ffffea00022b6900 count:1 mapcount:0 mapping:ffff88808ada4180 index:0x0 compound_mapcount: 0 [ 48.160410] flags: 0xfffe0000008100(slab|head) [ 48.160419] raw: 00fffe0000008100 ffff88808ada4180 0000000000000000 0000000100000003 [ 48.160427] raw: ffffea00022949a0 ffff88812fe54948 ffff88812fe56c40 0000000000000000 [ 48.160431] page dumped because: kasan: bad access detected [ 48.160433] [ 48.160435] Memory state around the buggy address: [ 48.160441] ffff88808ada5280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.160447] ffff88808ada5300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.160453] >ffff88808ada5380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.160456] ^ [ 48.160461] ffff88808ada5400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.160467] ffff88808ada5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.160470] ================================================================== [ 48.160473] Disabling lock debugging due to kernel taint [ 48.161472] Kernel panic - not syncing: panic_on_warn set ... [ 48.161472] [ 48.161481] CPU: 1 PID: 7532 Comm: syz-executor261 Tainted: G B 4.14.174-syzkaller #0 [ 48.161484] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.161486] Call Trace: [ 48.161497] dump_stack+0x13e/0x194 [ 48.161505] panic+0x1f9/0x42d [ 48.161512] ? add_taint.cold+0x16/0x16 [ 48.161520] ? preempt_schedule_common+0x4a/0xc0 [ 48.161528] ? con_shutdown+0x7f/0x90 [ 48.161535] ? ___preempt_schedule+0x16/0x18 [ 48.161543] ? con_shutdown+0x7f/0x90 [ 48.161551] kasan_end_report+0x43/0x49 [ 48.161558] kasan_report.cold+0x12f/0x2ae [ 48.161564] ? set_palette+0x130/0x130 [ 48.161570] con_shutdown+0x7f/0x90 [ 48.161578] release_tty+0xb6/0x7a0 [ 48.161585] tty_release_struct+0x37/0x50 [ 48.161591] tty_release+0xaa6/0xd60 [ 48.161600] ? tty_release_struct+0x50/0x50 [ 48.161607] __fput+0x25f/0x790 [ 48.161617] task_work_run+0x113/0x190 [ 48.161626] do_exit+0x9f2/0x2b00 [ 48.161632] ? __do_page_fault+0x4e4/0xb40 [ 48.161640] ? mm_update_next_owner+0x5b0/0x5b0 [ 48.161648] ? lock_downgrade+0x6e0/0x6e0 [ 48.161658] do_group_exit+0x100/0x310 [ 48.161665] SyS_exit_group+0x19/0x20 [ 48.161671] ? do_group_exit+0x310/0x310 [ 48.161678] do_syscall_64+0x1d5/0x640 [ 48.161688] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 48.161693] RIP: 0033:0x43ff38 [ 48.161697] RSP: 002b:00007ffcb9bdf7b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 48.161711] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 48.161715] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 48.161718] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 48.161722] R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000001 [ 48.161725] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 48.163065] Kernel Offset: disabled [ 48.757213] Rebooting in 86400 seconds..