[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   19.605959] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   25.733006] random: sshd: uninitialized urandom read (32 bytes read)
[   26.053156] random: sshd: uninitialized urandom read (32 bytes read)
[   26.937610] random: sshd: uninitialized urandom read (32 bytes read)
[   27.095528] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.0.40' (ECDSA) to the list of known hosts.
[   32.584818] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   32.703575] ==================================================================
[   32.711430] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   32.718264] Read of size 1006 at addr ffff8801a83ffff2 by task syz-executor088/4569
[   32.726050] 
[   32.727694] CPU: 1 PID: 4569 Comm: syz-executor088 Not tainted 4.18.0-rc3+ #4
[   32.734957] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   32.744310] Call Trace:
[   32.746891]  dump_stack+0x1c9/0x2b4
[   32.750504]  ? dump_stack_print_info.cold.2+0x52/0x52
[   32.755689]  ? printk+0xa7/0xcf
[   32.758998]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   32.763758]  ? _copy_to_user+0xe9/0x110
[   32.767728]  print_address_description+0x6c/0x20b
[   32.772589]  ? _copy_to_user+0xe9/0x110
[   32.776580]  kasan_report.cold.7+0x242/0x2fe
[   32.781429]  check_memory_region+0x13e/0x1b0
[   32.786038]  kasan_check_read+0x11/0x20
[   32.790038]  _copy_to_user+0xe9/0x110
[   32.793849]  bpf_test_finish.isra.7+0xee/0x1f0
[   32.798427]  ? bpf_test_init.isra.8+0x100/0x100
[   32.803081]  ? bpf_test_run+0x278/0x3b0
[   32.807055]  ? bpf_test_run+0x2fc/0x3b0
[   32.811044]  bpf_prog_test_run_skb+0x7d7/0xa30
[   32.815632]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   32.820760]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   32.826308]  ? __bpf_prog_get+0x9b/0x290
[   32.830374]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   32.835212]  bpf_prog_test_run+0x130/0x1a0
[   32.839447]  __x64_sys_bpf+0x3d8/0x510
[   32.843325]  ? bpf_prog_get+0x20/0x20
[   32.847130]  ? do_syscall_64+0x9a/0x820
[   32.851101]  do_syscall_64+0x1b9/0x820
[   32.854993]  ? syscall_return_slowpath+0x5e0/0x5e0
[   32.859949]  ? syscall_return_slowpath+0x31d/0x5e0
[   32.864897]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   32.870275]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   32.875135]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   32.880327] RIP: 0033:0x440319
[   32.883511] 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 
[   32.902765] RSP: 002b:00007ffec8f1ca18 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   32.910469] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440319
[   32.917735] RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a
[   32.925021] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   32.932298] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ba0
[   32.939561] R13: 0000000000401c30 R14: 0000000000000000 R15: 0000000000000000
[   32.946833] 
[   32.948458] The buggy address belongs to the page:
[   32.953389] page:ffffea0006a0ffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   32.961526] flags: 0x2fffc0000000000()
[   32.965412] raw: 02fffc0000000000 ffffea0006a0ffc8 ffffea0006a0ffc8 0000000000000000
[   32.973290] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   32.981182] page dumped because: kasan: bad access detected
[   32.986881] 
[   32.988503] Memory state around the buggy address:
[   32.993429]  ffff8801a83ffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   33.000785]  ffff8801a83fff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   33.008133] >ffff8801a83fff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   33.015482]                                                              ^
[   33.022495]  ffff8801a8400000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   33.029843]  ffff8801a8400080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   33.037194] ==================================================================
[   33.044542] Disabling lock debugging due to kernel taint
[   33.050075] Kernel panic - not syncing: panic_on_warn set ...
[   33.050075] 
[   33.057444] CPU: 1 PID: 4569 Comm: syz-executor088 Tainted: G    B             4.18.0-rc3+ #4
[   33.066099] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   33.075440] Call Trace:
[   33.078024]  dump_stack+0x1c9/0x2b4
[   33.081651]  ? dump_stack_print_info.cold.2+0x52/0x52
[   33.086836]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   33.091594]  panic+0x238/0x4e7
[   33.094771]  ? add_taint.cold.5+0x16/0x16
[   33.098915]  ? do_raw_spin_unlock+0xa7/0x2f0
[   33.103320]  ? do_raw_spin_unlock+0xa7/0x2f0
[   33.107731]  ? _copy_to_user+0xe9/0x110
[   33.111718]  kasan_end_report+0x47/0x4f
[   33.115694]  kasan_report.cold.7+0x76/0x2fe
[   33.120033]  check_memory_region+0x13e/0x1b0
[   33.124449]  kasan_check_read+0x11/0x20
[   33.128431]  _copy_to_user+0xe9/0x110
[   33.132221]  bpf_test_finish.isra.7+0xee/0x1f0
[   33.136790]  ? bpf_test_init.isra.8+0x100/0x100
[   33.141459]  ? bpf_test_run+0x278/0x3b0
[   33.145441]  ? bpf_test_run+0x2fc/0x3b0
[   33.149413]  bpf_prog_test_run_skb+0x7d7/0xa30
[   33.154000]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   33.158852]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   33.164404]  ? __bpf_prog_get+0x9b/0x290
[   33.168462]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   33.173302]  bpf_prog_test_run+0x130/0x1a0
[   33.177531]  __x64_sys_bpf+0x3d8/0x510
[   33.181424]  ? bpf_prog_get+0x20/0x20
[   33.185234]  ? do_syscall_64+0x9a/0x820
[   33.189207]  do_syscall_64+0x1b9/0x820
[   33.193094]  ? syscall_return_slowpath+0x5e0/0x5e0
[   33.198016]  ? syscall_return_slowpath+0x31d/0x5e0
[   33.202955]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   33.208317]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   33.213155]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   33.218327] RIP: 0033:0x440319
[   33.221492] 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 
[   33.240629] RSP: 002b:00007ffec8f1ca18 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   33.248333] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440319
[   33.255605] RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a
[   33.262866] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   33.270141] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ba0
[   33.277409] R13: 0000000000401c30 R14: 0000000000000000 R15: 0000000000000000
[   33.285179] Dumping ftrace buffer:
[   33.288728]    (ftrace buffer empty)
[   33.292427] Kernel Offset: disabled
[   33.296047] Rebooting in 86400 seconds..