[....] Starting OpenBSD Secure Shell server: sshd[   19.397450] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   23.731298] random: sshd: uninitialized urandom read (32 bytes read)
[   24.180797] random: sshd: uninitialized urandom read (32 bytes read)
[   25.049397] random: sshd: uninitialized urandom read (32 bytes read)
[   25.196844] sshd (4513) used greatest stack depth: 17048 bytes left
[   25.215568] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.20' (ECDSA) to the list of known hosts.
[   30.663617] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   35.776194] ==================================================================
[   35.783697] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   35.789997] Read of size 924 at addr ffff8801a6fffff2 by task syz-executor108/4525
[   35.797681] 
[   35.799292] CPU: 0 PID: 4525 Comm: syz-executor108 Not tainted 4.18.0-rc4+ #139
[   35.806718] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   35.816053] Call Trace:
[   35.818641]  dump_stack+0x1c9/0x2b4
[   35.822254]  ? dump_stack_print_info.cold.2+0x52/0x52
[   35.827516]  ? printk+0xa7/0xcf
[   35.830788]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   35.835533]  ? _copy_to_user+0xe9/0x110
[   35.839501]  print_address_description+0x6c/0x20b
[   35.844334]  ? _copy_to_user+0xe9/0x110
[   35.848290]  kasan_report.cold.7+0x242/0x2fe
[   35.852692]  check_memory_region+0x13e/0x1b0
[   35.857086]  kasan_check_read+0x11/0x20
[   35.861056]  _copy_to_user+0xe9/0x110
[   35.864852]  bpf_test_finish.isra.7+0xee/0x1f0
[   35.869419]  ? bpf_test_init.isra.8+0x100/0x100
[   35.874070]  ? bpf_test_run+0x2c0/0x3b0
[   35.878025]  ? bpf_test_run+0xe8/0x3b0
[   35.881897]  ? bpf_test_run+0x2fc/0x3b0
[   35.885859]  bpf_prog_test_run_skb+0x7d7/0xa30
[   35.890428]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   35.895266]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   35.900787]  ? __bpf_prog_get+0x9b/0x290
[   35.904832]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   35.909659]  bpf_prog_test_run+0x130/0x1a0
[   35.913886]  __x64_sys_bpf+0x3d8/0x510
[   35.917765]  ? bpf_prog_get+0x20/0x20
[   35.921561]  ? do_syscall_64+0x9a/0x820
[   35.925527]  do_syscall_64+0x1b9/0x820
[   35.929400]  ? syscall_return_slowpath+0x5e0/0x5e0
[   35.934313]  ? syscall_return_slowpath+0x31d/0x5e0
[   35.939229]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   35.944761]  ? retint_user+0x18/0x18
[   35.948472]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   35.953311]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   35.958485] RIP: 0033:0x4408d9
[   35.961655] Code: e8 4c b2 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 3b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 
[   35.980834] RSP: 002b:00007ffd76873ed8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   35.988537] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   35.995790] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   36.003042] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   36.010294] R10: 0000000000d0e880 R11: 0000000000000213 R12: 0000000000401da0
[   36.017550] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   36.024815] 
[   36.026422] The buggy address belongs to the page:
[   36.031334] page:ffffea00069bffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   36.039460] flags: 0x2fffc0000000000()
[   36.043333] raw: 02fffc0000000000 ffffea00069bffc8 ffffea00069bffc8 0000000000000000
[   36.051198] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   36.059056] page dumped because: kasan: bad access detected
[   36.064744] 
[   36.066346] Memory state around the buggy address:
[   36.071255]  ffff8801a6fffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   36.078603]  ffff8801a6ffff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   36.085949] >ffff8801a6ffff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   36.093308]                                                              ^
[   36.100307]  ffff8801a7000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   36.107655]  ffff8801a7000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   36.115001] ==================================================================
[   36.122339] Disabling lock debugging due to kernel taint
[   36.127876] Kernel panic - not syncing: panic_on_warn set ...
[   36.127876] 
[   36.135272] CPU: 0 PID: 4525 Comm: syz-executor108 Tainted: G    B             4.18.0-rc4+ #139
[   36.144087] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   36.153418] Call Trace:
[   36.155992]  dump_stack+0x1c9/0x2b4
[   36.159606]  ? dump_stack_print_info.cold.2+0x52/0x52
[   36.164782]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   36.169523]  panic+0x238/0x4e7
[   36.172701]  ? add_taint.cold.5+0x16/0x16
[   36.176841]  ? do_raw_spin_unlock+0xa7/0x2f0
[   36.181239]  ? do_raw_spin_unlock+0xa7/0x2f0
[   36.185637]  ? _copy_to_user+0xe9/0x110
[   36.189595]  kasan_end_report+0x47/0x4f
[   36.193551]  kasan_report.cold.7+0x76/0x2fe
[   36.197867]  check_memory_region+0x13e/0x1b0
[   36.202381]  kasan_check_read+0x11/0x20
[   36.206340]  _copy_to_user+0xe9/0x110
[   36.210221]  bpf_test_finish.isra.7+0xee/0x1f0
[   36.214788]  ? bpf_test_init.isra.8+0x100/0x100
[   36.219437]  ? bpf_test_run+0x2c0/0x3b0
[   36.223392]  ? bpf_test_run+0xe8/0x3b0
[   36.227260]  ? bpf_test_run+0x2fc/0x3b0
[   36.231220]  bpf_prog_test_run_skb+0x7d7/0xa30
[   36.235787]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   36.240618]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   36.246139]  ? __bpf_prog_get+0x9b/0x290
[   36.250183]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   36.255013]  bpf_prog_test_run+0x130/0x1a0
[   36.259242]  __x64_sys_bpf+0x3d8/0x510
[   36.263111]  ? bpf_prog_get+0x20/0x20
[   36.266911]  ? do_syscall_64+0x9a/0x820
[   36.270870]  do_syscall_64+0x1b9/0x820
[   36.274751]  ? syscall_return_slowpath+0x5e0/0x5e0
[   36.279667]  ? syscall_return_slowpath+0x31d/0x5e0
[   36.284594]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   36.290122]  ? retint_user+0x18/0x18
[   36.293821]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   36.298654]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   36.303824] RIP: 0033:0x4408d9
[   36.306989] Code: e8 4c b2 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 3b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 
[   36.326122] RSP: 002b:00007ffd76873ed8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   36.333815] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   36.341068] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   36.348319] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   36.355570] R10: 0000000000d0e880 R11: 0000000000000213 R12: 0000000000401da0
[   36.362822] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   36.370575] Dumping ftrace buffer:
[   36.374096]    (ftrace buffer empty)
[   36.377786] Kernel Offset: disabled
[   36.381394] Rebooting in 86400 seconds..