[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   19.058310] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   23.427548] random: sshd: uninitialized urandom read (32 bytes read)
[   23.891305] random: sshd: uninitialized urandom read (32 bytes read)
[   24.766784] random: sshd: uninitialized urandom read (32 bytes read)
[   24.927797] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.0.56' (ECDSA) to the list of known hosts.
[   30.927522] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   36.767218] ==================================================================
[   36.774924] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   36.781248] Read of size 924 at addr ffff8801a7bffff2 by task syz-executor358/4534
[   36.788961] 
[   36.790577] CPU: 0 PID: 4534 Comm: syz-executor358 Not tainted 4.18.0-rc3+ #4
[   36.797835] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   36.807177] Call Trace:
[   36.809766]  dump_stack+0x1c9/0x2b4
[   36.813377]  ? dump_stack_print_info.cold.2+0x52/0x52
[   36.818549]  ? printk+0xa7/0xcf
[   36.821813]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   36.826555]  ? _copy_to_user+0xe9/0x110
[   36.830512]  print_address_description+0x6c/0x20b
[   36.835348]  ? _copy_to_user+0xe9/0x110
[   36.839318]  kasan_report.cold.7+0x242/0x2fe
[   36.843712]  check_memory_region+0x13e/0x1b0
[   36.848104]  kasan_check_read+0x11/0x20
[   36.852070]  _copy_to_user+0xe9/0x110
[   36.855858]  bpf_test_finish.isra.7+0xee/0x1f0
[   36.860424]  ? bpf_test_init.isra.8+0x100/0x100
[   36.865081]  ? debug_lockdep_rcu_enabled.part.1+0x2a/0x60
[   36.870609]  ? bpf_test_run+0x2fc/0x3b0
[   36.874582]  bpf_prog_test_run_skb+0x7d7/0xa30
[   36.879157]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   36.883981]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   36.889500]  ? __bpf_prog_get+0x9b/0x290
[   36.893554]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   36.898376]  bpf_prog_test_run+0x130/0x1a0
[   36.902605]  __x64_sys_bpf+0x3d8/0x510
[   36.906485]  ? bpf_prog_get+0x20/0x20
[   36.910290]  ? do_syscall_64+0x9a/0x820
[   36.914250]  do_syscall_64+0x1b9/0x820
[   36.918120]  ? syscall_return_slowpath+0x5e0/0x5e0
[   36.923037]  ? syscall_return_slowpath+0x31d/0x5e0
[   36.927963]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   36.933483]  ? retint_user+0x18/0x18
[   36.937193]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   36.942032]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   36.947210] RIP: 0033:0x4408d9
[   36.950390] 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 
[   36.969571] RSP: 002b:00007ffdbfd1efe8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   36.977268] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   36.984533] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   36.991798] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   36.999058] R10: 000000000181a880 R11: 0000000000000213 R12: 0000000000401da0
[   37.006308] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   37.013572] 
[   37.015180] The buggy address belongs to the page:
[   37.020093] page:ffffea00069effc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   37.028218] flags: 0x2fffc0000000000()
[   37.032089] raw: 02fffc0000000000 ffffea00069effc8 ffffea00069effc8 0000000000000000
[   37.039962] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   37.047830] page dumped because: kasan: bad access detected
[   37.053622] 
[   37.055238] Memory state around the buggy address:
[   37.060148]  ffff8801a7bffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   37.067501]  ffff8801a7bfff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   37.074839] >ffff8801a7bfff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   37.082184]                                                              ^
[   37.089192]  ffff8801a7c00000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   37.096542]  ffff8801a7c00080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   37.103889] ==================================================================
[   37.111234] Disabling lock debugging due to kernel taint
[   37.116819] Kernel panic - not syncing: panic_on_warn set ...
[   37.116819] 
[   37.124197] CPU: 0 PID: 4534 Comm: syz-executor358 Tainted: G    B             4.18.0-rc3+ #4
[   37.132846] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   37.142189] Call Trace:
[   37.144761]  dump_stack+0x1c9/0x2b4
[   37.148372]  ? dump_stack_print_info.cold.2+0x52/0x52
[   37.153562]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   37.158301]  panic+0x238/0x4e7
[   37.161476]  ? add_taint.cold.5+0x16/0x16
[   37.165605]  ? do_raw_spin_unlock+0xa7/0x2f0
[   37.169991]  ? do_raw_spin_unlock+0xa7/0x2f0
[   37.174383]  ? _copy_to_user+0xe9/0x110
[   37.178351]  kasan_end_report+0x47/0x4f
[   37.182302]  kasan_report.cold.7+0x76/0x2fe
[   37.186612]  check_memory_region+0x13e/0x1b0
[   37.191015]  kasan_check_read+0x11/0x20
[   37.194973]  _copy_to_user+0xe9/0x110
[   37.198756]  bpf_test_finish.isra.7+0xee/0x1f0
[   37.203320]  ? bpf_test_init.isra.8+0x100/0x100
[   37.207993]  ? debug_lockdep_rcu_enabled.part.1+0x2a/0x60
[   37.213515]  ? bpf_test_run+0x2fc/0x3b0
[   37.217470]  bpf_prog_test_run_skb+0x7d7/0xa30
[   37.222035]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   37.226858]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   37.232375]  ? __bpf_prog_get+0x9b/0x290
[   37.236416]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   37.241237]  bpf_prog_test_run+0x130/0x1a0
[   37.245460]  __x64_sys_bpf+0x3d8/0x510
[   37.249326]  ? bpf_prog_get+0x20/0x20
[   37.253109]  ? do_syscall_64+0x9a/0x820
[   37.257067]  do_syscall_64+0x1b9/0x820
[   37.260936]  ? syscall_return_slowpath+0x5e0/0x5e0
[   37.265861]  ? syscall_return_slowpath+0x31d/0x5e0
[   37.270772]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   37.276306]  ? retint_user+0x18/0x18
[   37.280000]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   37.284831]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   37.290001] RIP: 0033:0x4408d9
[   37.293172] 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 
[   37.312303] RSP: 002b:00007ffdbfd1efe8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   37.319998] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   37.327267] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   37.334515] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   37.341766] R10: 000000000181a880 R11: 0000000000000213 R12: 0000000000401da0
[   37.349019] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   37.356773] Dumping ftrace buffer:
[   37.360292]    (ftrace buffer empty)
[   37.363979] Kernel Offset: disabled
[   37.367585] Rebooting in 86400 seconds..