[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 14.163817] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 18.317099] random: sshd: uninitialized urandom read (32 bytes read) [ 18.585172] random: sshd: uninitialized urandom read (32 bytes read) [ 19.063804] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.61' (ECDSA) to the list of known hosts. [ 24.842805] urandom_read: 1 callbacks suppressed [ 24.842809] 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 executing program executing program executing program [ 25.059826] ------------[ cut here ]------------ [ 25.064698] WARNING: CPU: 1 PID: 2024 at fs/direct-io.c:293 dio_complete+0x578/0x800 [ 25.072581] Kernel panic - not syncing: panic_on_warn set ... [ 25.072581] [ 25.079965] CPU: 1 PID: 2024 Comm: syz-executor821 Not tainted 4.14.67+ #1 [ 25.087093] Call Trace: [ 25.089696] dump_stack+0xb9/0x11b [ 25.093233] ? dio_complete+0x4c0/0x800 [ 25.097211] panic+0x1bf/0x3a4 [ 25.100422] ? add_taint.cold.4+0x16/0x16 [ 25.104750] ? __probe_kernel_read+0x163/0x1c0 [ 25.109465] ? dio_complete+0x578/0x800 [ 25.113700] __warn.cold.7+0x148/0x185 [ 25.117635] ? dio_complete+0x578/0x800 [ 25.121653] report_bug+0x1f7/0x26c [ 25.125319] do_error_trap+0x1ba/0x2c0 [ 25.129226] ? math_error+0x2d0/0x2d0 [ 25.133021] ? clear_shadow_entry+0x190/0x190 [ 25.137516] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.142367] invalid_op+0x18/0x40 [ 25.145837] RIP: 0010:dio_complete+0x578/0x800 [ 25.150424] RSP: 0018:ffff8801bdd97070 EFLAGS: 00010297 [ 25.155799] RAX: ffff8801d18d9780 RBX: ffff8801c29ba700 RCX: 0000000000000000 [ 25.163079] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801d18d97a4 [ 25.170354] RBP: 0000000000010000 R08: 0000000000000001 R09: 0000000000000000 [ 25.177642] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801c6c89418 [ 25.184915] R13: 0000000000010000 R14: 0000000000000002 R15: ffff8801c29ba798 [ 25.192231] ? ext4_update_bh_state+0xe0/0xe0 [ 25.196752] __blockdev_direct_IO+0x7614/0xc4e0 [ 25.201468] ? sb_init_dio_done_wq+0x70/0x70 [ 25.205891] ? trace_hardirqs_on+0x10/0x10 [ 25.210442] ? ext4_dio_get_block_unwritten_async+0x1b0/0x1b0 [ 25.216479] ? ext4_dio_get_block_unwritten_async+0x1b0/0x1b0 [ 25.222368] ext4_direct_IO+0x905/0x27f0 [ 25.226437] ? __filemap_fdatawait_range+0x1c2/0x260 [ 25.231545] ? ext4_da_write_begin+0x1050/0x1050 [ 25.236326] ? current_time+0x89/0xb0 [ 25.240134] ? filemap_check_errors+0x8b/0xb0 [ 25.244657] generic_file_direct_write+0x225/0x430 [ 25.249626] __generic_file_write_iter+0x213/0x540 [ 25.254573] ? generic_write_checks+0x252/0x410 [ 25.259280] ext4_file_write_iter+0x4f6/0xe20 [ 25.263796] ? ext4_file_mmap+0x1a0/0x1a0 [ 25.267953] ? kasan_kmalloc.part.1+0xa9/0xd0 [ 25.272444] ? kasan_kmalloc.part.1+0x4f/0xd0 [ 25.277122] ? __kmalloc+0x153/0x340 [ 25.280830] ? iter_file_splice_write+0x142/0xab0 [ 25.285673] ? direct_splice_actor+0x116/0x160 [ 25.290247] ? splice_direct_to_actor+0x28c/0x750 [ 25.295083] ? do_splice_direct+0x17b/0x220 [ 25.299572] do_iter_readv_writev+0x3a4/0x560 [ 25.304104] ? clone_verify_area+0x1e0/0x1e0 [ 25.308520] ? security_file_permission+0x88/0x1e0 [ 25.313461] do_iter_write+0x156/0x530 [ 25.317359] ? kasan_unpoison_shadow+0x30/0x40 [ 25.321934] ? kasan_kmalloc+0x76/0xc0 [ 25.325819] vfs_iter_write+0x70/0xa0 [ 25.329640] iter_file_splice_write+0x5b4/0xab0 [ 25.334311] ? vmsplice_to_user+0x1e0/0x1e0 [ 25.338840] ? avc_policy_seqno+0x5/0x10 [ 25.343078] ? vmsplice_to_user+0x1e0/0x1e0 [ 25.347512] direct_splice_actor+0x116/0x160 [ 25.351931] splice_direct_to_actor+0x28c/0x750 [ 25.356820] ? pipe_to_sendpage+0x300/0x300 [ 25.361150] ? do_splice_to+0x150/0x150 [ 25.365120] ? security_file_permission+0x88/0x1e0 [ 25.370064] do_splice_direct+0x17b/0x220 [ 25.374220] ? splice_direct_to_actor+0x750/0x750 [ 25.379210] ? rcu_read_lock_sched_held+0x102/0x120 [ 25.384227] do_sendfile+0x4a1/0xb50 [ 25.387956] ? do_compat_pwritev64+0x170/0x170 [ 25.392543] ? __might_fault+0xd4/0x1b0 [ 25.396514] ? __might_fault+0x177/0x1b0 [ 25.400571] SyS_sendfile64+0xab/0x140 [ 25.404485] ? SyS_sendfile+0x150/0x150 [ 25.408576] ? do_syscall_64+0x43/0x4b0 [ 25.412578] ? SyS_sendfile+0x150/0x150 [ 25.416573] do_syscall_64+0x19b/0x4b0 [ 25.420670] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 25.425857] RIP: 0033:0x446639 [ 25.429043] RSP: 002b:00007ff996034d18 EFLAGS: 00000297 ORIG_RAX: 0000000000000028 [ 25.436743] RAX: ffffffffffffffda RBX: 00000000006dbc48 RCX: 0000000000446639 [ 25.444004] RDX: 0000000020d83ff8 RSI: 0000000000000006 RDI: 0000000000000004 [ 25.451266] RBP: 00000000006dbc40 R08: 65732f636f72702f R09: 65732f636f72702f [ 25.458540] R10: 00008000fffffffe R11: 0000000000000297 R12: 00000000006dbc4c [ 25.465816] R13: 00007ff996034d20 R14: 0000000000000000 R15: 0000000000000000 [ 25.473741] Dumping ftrace buffer: [ 25.477556] (ftrace buffer empty) [ 25.481544] Kernel Offset: 0x3a000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 25.492944] Rebooting in 86400 seconds..