[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   19.918753] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   23.299557] random: sshd: uninitialized urandom read (32 bytes read)
[   23.776658] random: sshd: uninitialized urandom read (32 bytes read)
[   24.637578] random: sshd: uninitialized urandom read (32 bytes read)
[   24.797727] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts.
[   30.256980] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   30.370071] ==================================================================
[   30.377669] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   30.383973] Read of size 1012 at addr ffff8801a73ffff2 by task syz-executor547/4544
[   30.391777] 
[   30.393397] CPU: 1 PID: 4544 Comm: syz-executor547 Not tainted 4.18.0-rc4+ #141
[   30.400823] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   30.410161] Call Trace:
[   30.412752]  dump_stack+0x1c9/0x2b4
[   30.416373]  ? dump_stack_print_info.cold.2+0x52/0x52
[   30.421553]  ? printk+0xa7/0xcf
[   30.424818]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   30.429560]  ? _copy_to_user+0xe9/0x110
[   30.433525]  print_address_description+0x6c/0x20b
[   30.438356]  ? _copy_to_user+0xe9/0x110
[   30.442316]  kasan_report.cold.7+0x242/0x2fe
[   30.446721]  check_memory_region+0x13e/0x1b0
[   30.451115]  kasan_check_read+0x11/0x20
[   30.455079]  _copy_to_user+0xe9/0x110
[   30.458870]  bpf_test_finish.isra.7+0xee/0x1f0
[   30.463434]  ? bpf_test_init.isra.8+0x100/0x100
[   30.468082]  ? bpf_test_run+0x2c0/0x3b0
[   30.472041]  ? bpf_test_run+0xed/0x3b0
[   30.475915]  ? bpf_test_run+0x2fc/0x3b0
[   30.479889]  bpf_prog_test_run_skb+0x7d7/0xa30
[   30.484461]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.489291]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   30.494811]  ? __bpf_prog_get+0x9b/0x290
[   30.498868]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.503693]  bpf_prog_test_run+0x130/0x1a0
[   30.507914]  __x64_sys_bpf+0x3d8/0x510
[   30.511783]  ? bpf_prog_get+0x20/0x20
[   30.515572]  ? do_syscall_64+0x9a/0x820
[   30.519538]  do_syscall_64+0x1b9/0x820
[   30.523417]  ? syscall_return_slowpath+0x5e0/0x5e0
[   30.528329]  ? syscall_return_slowpath+0x31d/0x5e0
[   30.533247]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   30.538595]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   30.543423]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   30.548593] RIP: 0033:0x440269
[   30.551760] 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 
[   30.570947] RSP: 002b:00007ffe985fbe28 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   30.578683] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   30.585940] RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a
[   30.593196] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   30.600465] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   30.607726] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   30.615000] 
[   30.616615] The buggy address belongs to the page:
[   30.621525] page:ffffea00069cffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   30.629644] flags: 0x2fffc0000000000()
[   30.633523] raw: 02fffc0000000000 ffffea00069cffc8 ffffea00069cffc8 0000000000000000
[   30.641391] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   30.649255] page dumped because: kasan: bad access detected
[   30.654939] 
[   30.656550] Memory state around the buggy address:
[   30.661457]  ffff8801a73ffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   30.668814]  ffff8801a73fff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   30.676153] >ffff8801a73fff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   30.683490]                                                              ^
[   30.690496]  ffff8801a7400000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   30.697839]  ffff8801a7400080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   30.705188] ==================================================================
[   30.712535] Disabling lock debugging due to kernel taint
[   30.718039] Kernel panic - not syncing: panic_on_warn set ...
[   30.718039] 
[   30.725410] CPU: 1 PID: 4544 Comm: syz-executor547 Tainted: G    B             4.18.0-rc4+ #141
[   30.734233] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   30.743564] Call Trace:
[   30.746153]  dump_stack+0x1c9/0x2b4
[   30.749763]  ? dump_stack_print_info.cold.2+0x52/0x52
[   30.754946]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   30.759703]  panic+0x238/0x4e7
[   30.762886]  ? add_taint.cold.5+0x16/0x16
[   30.767024]  ? do_raw_spin_unlock+0xa7/0x2f0
[   30.771418]  ? do_raw_spin_unlock+0xa7/0x2f0
[   30.775808]  ? _copy_to_user+0xe9/0x110
[   30.779768]  kasan_end_report+0x47/0x4f
[   30.783722]  kasan_report.cold.7+0x76/0x2fe
[   30.788034]  check_memory_region+0x13e/0x1b0
[   30.792433]  kasan_check_read+0x11/0x20
[   30.796394]  _copy_to_user+0xe9/0x110
[   30.800215]  bpf_test_finish.isra.7+0xee/0x1f0
[   30.804788]  ? bpf_test_init.isra.8+0x100/0x100
[   30.809449]  ? bpf_test_run+0x2c0/0x3b0
[   30.813416]  ? bpf_test_run+0xed/0x3b0
[   30.817303]  ? bpf_test_run+0x2fc/0x3b0
[   30.821266]  bpf_prog_test_run_skb+0x7d7/0xa30
[   30.825845]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.830682]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   30.836214]  ? __bpf_prog_get+0x9b/0x290
[   30.840260]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.845092]  bpf_prog_test_run+0x130/0x1a0
[   30.849332]  __x64_sys_bpf+0x3d8/0x510
[   30.853206]  ? bpf_prog_get+0x20/0x20
[   30.856993]  ? do_syscall_64+0x9a/0x820
[   30.860963]  do_syscall_64+0x1b9/0x820
[   30.864838]  ? syscall_return_slowpath+0x5e0/0x5e0
[   30.869754]  ? syscall_return_slowpath+0x31d/0x5e0
[   30.874672]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   30.880033]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   30.884863]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   30.890049] RIP: 0033:0x440269
[   30.893218] 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 
[   30.912615] RSP: 002b:00007ffe985fbe28 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   30.920313] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   30.927573] RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a
[   30.934834] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   30.942094] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   30.949429] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   30.957291] Dumping ftrace buffer:
[   30.960825]    (ftrace buffer empty)
[   30.964519] Kernel Offset: disabled
[   30.968137] Rebooting in 86400 seconds..