. [ 37.421093] audit: type=1800 audit(1583859480.682:34): pid=7371 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 [ 37.659084] random: sshd: uninitialized urandom read (32 bytes read) [ 37.973383] audit: type=1400 audit(1583859481.262:35): avc: denied { map } for pid=7543 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 [ 38.025346] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 38.763998] random: sshd: uninitialized urandom read (32 bytes read) [ 38.967817] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.247' (ECDSA) to the list of known hosts. [ 44.620162] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 44.753252] audit: type=1400 audit(1583859488.042:36): avc: denied { map } for pid=7555 comm="syz-executor082" path="/root/syz-executor082347070" 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 [ 44.800446] ================================================================== [ 44.800480] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 44.800485] Write of size 8 at addr ffff88807bf53708 by task syz-executor082/7562 [ 44.800487] [ 44.800495] CPU: 1 PID: 7562 Comm: syz-executor082 Not tainted 4.14.172-syzkaller #0 [ 44.800499] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.800502] Call Trace: [ 44.800516] dump_stack+0x13e/0x194 [ 44.800525] ? con_shutdown+0x7f/0x90 [ 44.800536] print_address_description.cold+0x7c/0x1e2 [ 44.800543] ? con_shutdown+0x7f/0x90 [ 44.800550] kasan_report.cold+0xa9/0x2ae [ 44.800558] ? set_palette+0x130/0x130 [ 44.800565] con_shutdown+0x7f/0x90 [ 44.800573] release_tty+0xb6/0x7a0 [ 44.800583] tty_release_struct+0x37/0x50 [ 44.800589] tty_release+0xaa6/0xd60 [ 44.800602] ? lock_downgrade+0x6e0/0x6e0 [ 44.800611] ? tty_release_struct+0x50/0x50 [ 44.800618] __fput+0x25f/0x790 [ 44.800638] task_work_run+0x113/0x190 [ 44.800651] do_exit+0x9f2/0x2b00 [ 44.800659] ? __do_page_fault+0x4e4/0xb40 [ 44.800669] ? mm_update_next_owner+0x5b0/0x5b0 [ 44.800678] ? lock_downgrade+0x6e0/0x6e0 [ 44.800689] do_group_exit+0x100/0x310 [ 44.800699] SyS_exit_group+0x19/0x20 [ 44.800706] ? do_group_exit+0x310/0x310 [ 44.800714] do_syscall_64+0x1d5/0x640 [ 44.800727] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.800733] RIP: 0033:0x43ff38 [ 44.800738] RSP: 002b:00007ffe509de0a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 44.800747] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 44.800751] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 44.800755] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 44.800759] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 44.800762] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 44.800774] [ 44.800778] Allocated by task 7562: [ 44.800784] save_stack+0x32/0xa0 [ 44.800788] kasan_kmalloc+0xbf/0xe0 [ 44.800793] kmem_cache_alloc_trace+0x14d/0x7b0 [ 44.800798] vc_allocate+0x142/0x550 [ 44.800802] con_install+0x4f/0x3e0 [ 44.800807] tty_init_dev+0xe1/0x3a0 [ 44.800811] tty_open+0x410/0x9c0 [ 44.800817] chrdev_open+0x1fc/0x540 [ 44.800823] do_dentry_open+0x732/0xe90 [ 44.800827] vfs_open+0x105/0x220 [ 44.800832] path_openat+0x8ca/0x3c50 [ 44.800837] do_filp_open+0x18e/0x250 [ 44.800841] do_sys_open+0x29d/0x3f0 [ 44.800846] do_syscall_64+0x1d5/0x640 [ 44.800857] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.800858] [ 44.800861] Freed by task 7563: [ 44.800865] save_stack+0x32/0xa0 [ 44.800869] kasan_slab_free+0x75/0xc0 [ 44.800873] kfree+0xcb/0x260 [ 44.800880] vt_disallocate_all+0x25c/0x340 [ 44.800883] vt_ioctl+0x6e3/0x1f00 [ 44.800888] tty_ioctl+0x6c5/0x1220 [ 44.800893] do_vfs_ioctl+0x75a/0xfe0 [ 44.800897] SyS_ioctl+0x7f/0xb0 [ 44.800902] do_syscall_64+0x1d5/0x640 [ 44.800906] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.800908] [ 44.800912] The buggy address belongs to the object at ffff88807bf53600 [ 44.800912] which belongs to the cache kmalloc-2048 of size 2048 [ 44.800917] The buggy address is located 264 bytes inside of [ 44.800917] 2048-byte region [ffff88807bf53600, ffff88807bf53e00) [ 44.800918] The buggy address belongs to the page: [ 44.800923] page:ffffea0001efd480 count:1 mapcount:0 mapping:ffff88807bf52500 index:0x0 compound_mapcount: 0 [ 44.800932] flags: 0xfffe0000008100(slab|head) [ 44.800939] raw: 00fffe0000008100 ffff88807bf52500 0000000000000000 0000000100000003 [ 44.800945] raw: ffffea00025853a0 ffffea000242b4a0 ffff88812fe56c40 0000000000000000 [ 44.800947] page dumped because: kasan: bad access detected [ 44.800949] [ 44.800951] Memory state around the buggy address: [ 44.800955] ffff88807bf53600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.800960] ffff88807bf53680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.800965] >ffff88807bf53700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.800968] ^ [ 44.800973] ffff88807bf53780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.800978] ffff88807bf53800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.800981] ================================================================== [ 44.800984] Disabling lock debugging due to kernel taint [ 44.802168] Kernel panic - not syncing: panic_on_warn set ... [ 44.802168] [ 44.802178] CPU: 1 PID: 7562 Comm: syz-executor082 Tainted: G B 4.14.172-syzkaller #0 [ 44.802182] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.802185] Call Trace: [ 44.802199] dump_stack+0x13e/0x194 [ 44.802208] panic+0x1f9/0x42d [ 44.802215] ? add_taint.cold+0x16/0x16 [ 44.802223] ? preempt_schedule_common+0x4a/0xc0 [ 44.802232] ? con_shutdown+0x7f/0x90 [ 44.802239] ? ___preempt_schedule+0x16/0x18 [ 44.802248] ? con_shutdown+0x7f/0x90 [ 44.802256] kasan_end_report+0x43/0x49 [ 44.802263] kasan_report.cold+0x12f/0x2ae [ 44.802270] ? set_palette+0x130/0x130 [ 44.802278] con_shutdown+0x7f/0x90 [ 44.802286] release_tty+0xb6/0x7a0 [ 44.802294] tty_release_struct+0x37/0x50 [ 44.802301] tty_release+0xaa6/0xd60 [ 44.802312] ? lock_downgrade+0x6e0/0x6e0 [ 44.802319] ? tty_release_struct+0x50/0x50 [ 44.802325] __fput+0x25f/0x790 [ 44.802336] task_work_run+0x113/0x190 [ 44.802344] do_exit+0x9f2/0x2b00 [ 44.802352] ? __do_page_fault+0x4e4/0xb40 [ 44.802359] ? mm_update_next_owner+0x5b0/0x5b0 [ 44.802365] ? lock_downgrade+0x6e0/0x6e0 [ 44.802373] do_group_exit+0x100/0x310 [ 44.802380] SyS_exit_group+0x19/0x20 [ 44.802384] ? do_group_exit+0x310/0x310 [ 44.802391] do_syscall_64+0x1d5/0x640 [ 44.802402] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.802407] RIP: 0033:0x43ff38 [ 44.802411] RSP: 002b:00007ffe509de0a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 44.802419] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 44.802423] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 44.802426] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 44.802430] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 44.802433] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 44.804374] Kernel Offset: disabled [ 45.424051] Rebooting in 86400 seconds..