[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   21.119646] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   26.989454] random: sshd: uninitialized urandom read (32 bytes read)
[   27.464258] random: sshd: uninitialized urandom read (32 bytes read)
[   28.350853] random: sshd: uninitialized urandom read (32 bytes read)
[   28.511438] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.11' (ECDSA) to the list of known hosts.
[   34.008418] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   34.123162] ==================================================================
[   34.130644] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   34.136983] Read of size 924 at addr ffff8801a6bffff2 by task syz-executor206/4573
[   34.144678] 
[   34.146293] CPU: 0 PID: 4573 Comm: syz-executor206 Not tainted 4.18.0-rc3+ #6
[   34.153552] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   34.162884] Call Trace:
[   34.165459]  dump_stack+0x1c9/0x2b4
[   34.169082]  ? dump_stack_print_info.cold.2+0x52/0x52
[   34.174250]  ? printk+0xa7/0xcf
[   34.177510]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   34.182263]  ? _copy_to_user+0xe9/0x110
[   34.186220]  print_address_description+0x6c/0x20b
[   34.191060]  ? _copy_to_user+0xe9/0x110
[   34.195032]  kasan_report.cold.7+0x242/0x2fe
[   34.199438]  check_memory_region+0x13e/0x1b0
[   34.203827]  kasan_check_read+0x11/0x20
[   34.207786]  _copy_to_user+0xe9/0x110
[   34.211570]  bpf_test_finish.isra.7+0xee/0x1f0
[   34.216152]  ? bpf_test_init.isra.8+0x100/0x100
[   34.220802]  ? bpf_test_run+0x259/0x3b0
[   34.224763]  ? bpf_test_run+0x267/0x3b0
[   34.228721]  ? bpf_test_run+0x2fc/0x3b0
[   34.232689]  bpf_prog_test_run_skb+0x7d7/0xa30
[   34.237261]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.242091]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   34.247623]  ? __bpf_prog_get+0x9b/0x290
[   34.251676]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.256503]  bpf_prog_test_run+0x130/0x1a0
[   34.260724]  __x64_sys_bpf+0x3d8/0x510
[   34.264590]  ? bpf_prog_get+0x20/0x20
[   34.268378]  ? do_syscall_64+0x9a/0x820
[   34.272338]  do_syscall_64+0x1b9/0x820
[   34.276217]  ? syscall_return_slowpath+0x5e0/0x5e0
[   34.281159]  ? syscall_return_slowpath+0x31d/0x5e0
[   34.286086]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   34.291446]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   34.296275]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   34.301444] RIP: 0033:0x440269
[   34.304611] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 
[   34.323788] RSP: 002b:00007ffc43a10498 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   34.331484] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   34.338740] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   34.345999] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   34.353260] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   34.360512] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   34.367779] 
[   34.369396] The buggy address belongs to the page:
[   34.374311] page:ffffea00069affc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   34.382453] flags: 0x2fffc0000000000()
[   34.386328] raw: 02fffc0000000000 ffffea00069affc8 ffffea00069affc8 0000000000000000
[   34.394194] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   34.402058] page dumped because: kasan: bad access detected
[   34.407750] 
[   34.409354] Memory state around the buggy address:
[   34.414356]  ffff8801a6bffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   34.421704]  ffff8801a6bfff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   34.429050] >ffff8801a6bfff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   34.436389]                                                              ^
[   34.443383]  ffff8801a6c00000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   34.450730]  ffff8801a6c00080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   34.458079] ==================================================================
[   34.465413] Disabling lock debugging due to kernel taint
[   34.470909] Kernel panic - not syncing: panic_on_warn set ...
[   34.470909] 
[   34.478279] CPU: 0 PID: 4573 Comm: syz-executor206 Tainted: G    B             4.18.0-rc3+ #6
[   34.486933] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   34.496275] Call Trace:
[   34.498851]  dump_stack+0x1c9/0x2b4
[   34.502461]  ? dump_stack_print_info.cold.2+0x52/0x52
[   34.507637]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   34.512378]  panic+0x238/0x4e7
[   34.515552]  ? add_taint.cold.5+0x16/0x16
[   34.519682]  ? do_raw_spin_unlock+0xa7/0x2f0
[   34.524069]  ? do_raw_spin_unlock+0xa7/0x2f0
[   34.528461]  ? _copy_to_user+0xe9/0x110
[   34.532416]  kasan_end_report+0x47/0x4f
[   34.536543]  kasan_report.cold.7+0x76/0x2fe
[   34.540846]  check_memory_region+0x13e/0x1b0
[   34.545245]  kasan_check_read+0x11/0x20
[   34.549209]  _copy_to_user+0xe9/0x110
[   34.552997]  bpf_test_finish.isra.7+0xee/0x1f0
[   34.557565]  ? bpf_test_init.isra.8+0x100/0x100
[   34.562216]  ? bpf_test_run+0x259/0x3b0
[   34.566189]  ? bpf_test_run+0x267/0x3b0
[   34.570168]  ? bpf_test_run+0x2fc/0x3b0
[   34.574122]  bpf_prog_test_run_skb+0x7d7/0xa30
[   34.578699]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.583523]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   34.589044]  ? __bpf_prog_get+0x9b/0x290
[   34.593094]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.597915]  bpf_prog_test_run+0x130/0x1a0
[   34.602140]  __x64_sys_bpf+0x3d8/0x510
[   34.606012]  ? bpf_prog_get+0x20/0x20
[   34.609803]  ? do_syscall_64+0x9a/0x820
[   34.613761]  do_syscall_64+0x1b9/0x820
[   34.617650]  ? syscall_return_slowpath+0x5e0/0x5e0
[   34.622560]  ? syscall_return_slowpath+0x31d/0x5e0
[   34.627473]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   34.632822]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   34.637653]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   34.642909] RIP: 0033:0x440269
[   34.646082] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 
[   34.665220] RSP: 002b:00007ffc43a10498 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   34.672911] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   34.680160] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   34.687413] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   34.694666] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   34.701916] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   34.709931] Dumping ftrace buffer:
[   34.713481]    (ftrace buffer empty)
[   34.717175] Kernel Offset: disabled
[   34.720791] Rebooting in 86400 seconds..