[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   19.151332] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   23.732775] random: sshd: uninitialized urandom read (32 bytes read)
[   23.991846] random: sshd: uninitialized urandom read (32 bytes read)
[   24.869158] random: sshd: uninitialized urandom read (32 bytes read)
[   25.034096] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.15.195' (ECDSA) to the list of known hosts.
[   30.598253] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   30.698293] ==================================================================
[   30.705801] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   30.712109] Read of size 978 at addr ffff8801a7fffff2 by task syz-executor326/4570
[   30.719789] 
[   30.721401] CPU: 1 PID: 4570 Comm: syz-executor326 Not tainted 4.18.0-rc4+ #144
[   30.728825] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   30.738167] Call Trace:
[   30.740749]  dump_stack+0x1c9/0x2b4
[   30.744372]  ? dump_stack_print_info.cold.2+0x52/0x52
[   30.749555]  ? printk+0xa7/0xcf
[   30.752827]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   30.757575]  ? _copy_to_user+0xe9/0x110
[   30.761543]  print_address_description+0x6c/0x20b
[   30.766374]  ? _copy_to_user+0xe9/0x110
[   30.770329]  kasan_report.cold.7+0x242/0x2fe
[   30.774723]  check_memory_region+0x13e/0x1b0
[   30.779116]  kasan_check_read+0x11/0x20
[   30.783078]  _copy_to_user+0xe9/0x110
[   30.786884]  bpf_test_finish.isra.7+0xee/0x1f0
[   30.791452]  ? bpf_test_init.isra.8+0x100/0x100
[   30.796110]  ? bpf_test_run+0x2fc/0x3b0
[   30.800070]  bpf_prog_test_run_skb+0x7d7/0xa30
[   30.804638]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.809466]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   30.814991]  ? __bpf_prog_get+0x9b/0x290
[   30.819047]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.823881]  bpf_prog_test_run+0x130/0x1a0
[   30.828099]  __x64_sys_bpf+0x3d8/0x510
[   30.831968]  ? bpf_prog_get+0x20/0x20
[   30.835767]  ? do_syscall_64+0x9a/0x820
[   30.839728]  do_syscall_64+0x1b9/0x820
[   30.843611]  ? syscall_return_slowpath+0x5e0/0x5e0
[   30.848522]  ? syscall_return_slowpath+0x31d/0x5e0
[   30.853439]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   30.858789]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   30.863616]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   30.868795] RIP: 0033:0x440259
[   30.871959] 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 
[   30.891153] RSP: 002b:00007ffec81d1878 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   30.898850] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440259
[   30.906100] RDX: 0000000000000028 RSI: 0000000020000280 RDI: 000000000000000a
[   30.913363] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   30.920615] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ae0
[   30.927877] R13: 0000000000401b70 R14: 0000000000000000 R15: 0000000000000000
[   30.935135] 
[   30.936740] The buggy address belongs to the page:
[   30.941647] page:ffffea00069fffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   30.949780] flags: 0x2fffc0000000000()
[   30.953652] raw: 02fffc0000000000 ffffea00069fffc8 ffffea00069fffc8 0000000000000000
[   30.961515] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   30.969372] page dumped because: kasan: bad access detected
[   30.975055] 
[   30.976659] Memory state around the buggy address:
[   30.981565]  ffff8801a7fffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   30.988911]  ffff8801a7ffff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   30.996247] >ffff8801a7ffff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   31.003582]                                                              ^
[   31.010574]  ffff8801a8000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   31.017914]  ffff8801a8000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   31.025253] ==================================================================
[   31.032589] Disabling lock debugging due to kernel taint
[   31.038142] Kernel panic - not syncing: panic_on_warn set ...
[   31.038142] 
[   31.045508] CPU: 1 PID: 4570 Comm: syz-executor326 Tainted: G    B             4.18.0-rc4+ #144
[   31.054335] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   31.063666] Call Trace:
[   31.066242]  dump_stack+0x1c9/0x2b4
[   31.069849]  ? dump_stack_print_info.cold.2+0x52/0x52
[   31.075025]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   31.079769]  panic+0x238/0x4e7
[   31.082943]  ? add_taint.cold.5+0x16/0x16
[   31.087072]  ? do_raw_spin_unlock+0xa7/0x2f0
[   31.091457]  ? do_raw_spin_unlock+0xa7/0x2f0
[   31.095846]  ? _copy_to_user+0xe9/0x110
[   31.099799]  kasan_end_report+0x47/0x4f
[   31.103758]  kasan_report.cold.7+0x76/0x2fe
[   31.108065]  check_memory_region+0x13e/0x1b0
[   31.112454]  kasan_check_read+0x11/0x20
[   31.116408]  _copy_to_user+0xe9/0x110
[   31.120196]  bpf_test_finish.isra.7+0xee/0x1f0
[   31.124761]  ? bpf_test_init.isra.8+0x100/0x100
[   31.129412]  ? bpf_test_run+0x2fc/0x3b0
[   31.133368]  bpf_prog_test_run_skb+0x7d7/0xa30
[   31.137943]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   31.142776]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   31.148294]  ? __bpf_prog_get+0x9b/0x290
[   31.152337]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   31.157159]  bpf_prog_test_run+0x130/0x1a0
[   31.161374]  __x64_sys_bpf+0x3d8/0x510
[   31.165243]  ? bpf_prog_get+0x20/0x20
[   31.169035]  ? do_syscall_64+0x9a/0x820
[   31.172990]  do_syscall_64+0x1b9/0x820
[   31.176860]  ? syscall_return_slowpath+0x5e0/0x5e0
[   31.181769]  ? syscall_return_slowpath+0x31d/0x5e0
[   31.186680]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   31.192040]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   31.196870]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   31.202046] RIP: 0033:0x440259
[   31.205209] 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 
[   31.224350] RSP: 002b:00007ffec81d1878 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   31.232041] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440259
[   31.239294] RDX: 0000000000000028 RSI: 0000000020000280 RDI: 000000000000000a
[   31.246538] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   31.253783] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ae0
[   31.261031] R13: 0000000000401b70 R14: 0000000000000000 R15: 0000000000000000
[   31.268736] Dumping ftrace buffer:
[   31.272252]    (ftrace buffer empty)
[   31.275939] Kernel Offset: disabled
[   31.279546] Rebooting in 86400 seconds..