[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   18.688212] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.
[   18.831920] random: sshd: uninitialized urandom read (32 bytes read)
[   19.074480] random: sshd: uninitialized urandom read (32 bytes read)
[   19.897205] random: sshd: uninitialized urandom read (32 bytes read)

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   20.056567] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.15' (ECDSA) to the list of known hosts.
[   25.513386] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   30.751182] ==================================================================
[   30.758647] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   30.764946] Read of size 924 at addr ffff8801a6bffff2 by task syz-executor857/4543
[   30.772626] 
[   30.774238] CPU: 1 PID: 4543 Comm: syz-executor857 Not tainted 4.18.0-rc4+ #139
[   30.781678] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   30.791008] Call Trace:
[   30.793587]  dump_stack+0x1c9/0x2b4
[   30.797193]  ? dump_stack_print_info.cold.2+0x52/0x52
[   30.802370]  ? printk+0xa7/0xcf
[   30.805630]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   30.810370]  ? _copy_to_user+0xe9/0x110
[   30.814324]  print_address_description+0x6c/0x20b
[   30.819147]  ? _copy_to_user+0xe9/0x110
[   30.823098]  kasan_report.cold.7+0x242/0x2fe
[   30.827490]  check_memory_region+0x13e/0x1b0
[   30.831879]  kasan_check_read+0x11/0x20
[   30.835834]  _copy_to_user+0xe9/0x110
[   30.839625]  bpf_test_finish.isra.7+0xee/0x1f0
[   30.844188]  ? bpf_test_init.isra.8+0x100/0x100
[   30.848837]  ? bpf_test_run+0xc3/0x3b0
[   30.852716]  ? bpf_test_run+0x2fc/0x3b0
[   30.856676]  bpf_prog_test_run_skb+0x7d7/0xa30
[   30.861243]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.866068]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   30.871584]  ? __bpf_prog_get+0x9b/0x290
[   30.875626]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   30.880446]  bpf_prog_test_run+0x130/0x1a0
[   30.884663]  __x64_sys_bpf+0x3d8/0x510
[   30.888529]  ? bpf_prog_get+0x20/0x20
[   30.892315]  ? do_syscall_64+0x9a/0x820
[   30.896278]  do_syscall_64+0x1b9/0x820
[   30.900144]  ? syscall_return_slowpath+0x5e0/0x5e0
[   30.905052]  ? syscall_return_slowpath+0x31d/0x5e0
[   30.909962]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   30.915481]  ? retint_user+0x18/0x18
[   30.919182]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   30.924008]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   30.929190] RIP: 0033:0x4408d9
[   30.932355] 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 
[   30.951521] RSP: 002b:00007ffc31e95158 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   30.959209] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   30.966457] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   30.973703] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   30.980951] R10: 0000000000ea7880 R11: 0000000000000213 R12: 0000000000401da0
[   30.988198] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   30.995451] 
[   30.997054] The buggy address belongs to the page:
[   31.001961] page:ffffea00069affc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   31.010083] flags: 0x2fffc0000000000()
[   31.013953] raw: 02fffc0000000000 ffffea00069affc8 ffffea00069affc8 0000000000000000
[   31.021815] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   31.029670] page dumped because: kasan: bad access detected
[   31.035359] 
[   31.036964] Memory state around the buggy address:
[   31.041876]  ffff8801a6bffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   31.049211]  ffff8801a6bfff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   31.056546] >ffff8801a6bfff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   31.063878]                                                              ^
[   31.070874]  ffff8801a6c00000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   31.078207]  ffff8801a6c00080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   31.085547] ==================================================================
[   31.092877] Disabling lock debugging due to kernel taint
[   31.098371] Kernel panic - not syncing: panic_on_warn set ...
[   31.098371] 
[   31.105733] CPU: 1 PID: 4543 Comm: syz-executor857 Tainted: G    B             4.18.0-rc4+ #139
[   31.114545] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   31.123875] Call Trace:
[   31.126444]  dump_stack+0x1c9/0x2b4
[   31.130051]  ? dump_stack_print_info.cold.2+0x52/0x52
[   31.135220]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   31.139957]  panic+0x238/0x4e7
[   31.143136]  ? add_taint.cold.5+0x16/0x16
[   31.147264]  ? do_raw_spin_unlock+0xa7/0x2f0
[   31.151649]  ? do_raw_spin_unlock+0xa7/0x2f0
[   31.156045]  ? _copy_to_user+0xe9/0x110
[   31.159998]  kasan_end_report+0x47/0x4f
[   31.163964]  kasan_report.cold.7+0x76/0x2fe
[   31.168274]  check_memory_region+0x13e/0x1b0
[   31.172661]  kasan_check_read+0x11/0x20
[   31.176619]  _copy_to_user+0xe9/0x110
[   31.180407]  bpf_test_finish.isra.7+0xee/0x1f0
[   31.184968]  ? bpf_test_init.isra.8+0x100/0x100
[   31.189613]  ? bpf_test_run+0xc3/0x3b0
[   31.193479]  ? bpf_test_run+0x2fc/0x3b0
[   31.197434]  bpf_prog_test_run_skb+0x7d7/0xa30
[   31.201993]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   31.206819]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   31.212342]  ? __bpf_prog_get+0x9b/0x290
[   31.216390]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   31.221207]  bpf_prog_test_run+0x130/0x1a0
[   31.225419]  __x64_sys_bpf+0x3d8/0x510
[   31.229282]  ? bpf_prog_get+0x20/0x20
[   31.233062]  ? do_syscall_64+0x9a/0x820
[   31.237031]  do_syscall_64+0x1b9/0x820
[   31.240897]  ? syscall_return_slowpath+0x5e0/0x5e0
[   31.245809]  ? syscall_return_slowpath+0x31d/0x5e0
[   31.250719]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   31.256231]  ? retint_user+0x18/0x18
[   31.259924]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   31.265426]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   31.270612] RIP: 0033:0x4408d9
[   31.273790] 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 
[   31.293007] RSP: 002b:00007ffc31e95158 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   31.300705] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   31.307953] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   31.315198] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   31.322444] R10: 0000000000ea7880 R11: 0000000000000213 R12: 0000000000401da0
[   31.329689] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   31.337423] Dumping ftrace buffer:
[   31.340939]    (ftrace buffer empty)
[   31.344631] Kernel Offset: disabled
[   31.348242] Rebooting in 86400 seconds..