[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   15.587915] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   19.766222] random: sshd: uninitialized urandom read (32 bytes read)
[   20.031549] random: sshd: uninitialized urandom read (32 bytes read)
[   20.720561] random: sshd: uninitialized urandom read (32 bytes read)
[   20.873356] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts.
[   26.301788] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   31.712051] ==================================================================
[   31.719495] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   31.725805] Read of size 924 at addr ffff8801a5fffff2 by task syz-executor480/4466
[   31.733500] 
[   31.735111] CPU: 1 PID: 4466 Comm: syz-executor480 Not tainted 4.18.0-rc3+ #48
[   31.742466] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   31.751813] Call Trace:
[   31.754393]  dump_stack+0x1c9/0x2b4
[   31.758027]  ? dump_stack_print_info.cold.2+0x52/0x52
[   31.763215]  ? printk+0xa7/0xcf
[   31.766481]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   31.771225]  ? _copy_to_user+0xe9/0x110
[   31.775192]  print_address_description+0x6c/0x20b
[   31.780025]  ? _copy_to_user+0xe9/0x110
[   31.783991]  kasan_report.cold.7+0x242/0x2fe
[   31.788392]  check_memory_region+0x13e/0x1b0
[   31.792779]  kasan_check_read+0x11/0x20
[   31.796746]  _copy_to_user+0xe9/0x110
[   31.800533]  bpf_test_finish.isra.7+0xee/0x1f0
[   31.805096]  ? bpf_test_init.isra.8+0x100/0x100
[   31.809747]  ? bpf_test_run+0xc3/0x3b0
[   31.813621]  ? bpf_test_run+0x2fc/0x3b0
[   31.817585]  bpf_prog_test_run_skb+0x7d7/0xa30
[   31.822173]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   31.827016]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   31.832538]  ? __bpf_prog_get+0x9b/0x290
[   31.836582]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   31.841407]  bpf_prog_test_run+0x130/0x1a0
[   31.845637]  __x64_sys_bpf+0x3d8/0x510
[   31.849509]  ? bpf_prog_get+0x20/0x20
[   31.853293]  ? do_page_fault+0xf6/0x8c0
[   31.857260]  do_syscall_64+0x1b9/0x820
[   31.861128]  ? syscall_return_slowpath+0x5e0/0x5e0
[   31.866046]  ? syscall_return_slowpath+0x31d/0x5e0
[   31.870969]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   31.876665]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   31.882206]  ? prepare_exit_to_usermode+0x291/0x3b0
[   31.887222]  ? perf_trace_sys_enter+0xb10/0xb10
[   31.891899]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   31.896751]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   31.901937] RIP: 0033:0x4408d9
[   31.905116] 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 
[   31.924368] RSP: 002b:00007ffdf5c246e8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   31.932070] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   31.939323] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   31.946571] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   31.953820] R10: 0000000001053880 R11: 0000000000000213 R12: 0000000000401da0
[   31.961070] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   31.968324] 
[   31.969941] The buggy address belongs to the page:
[   31.974849] page:ffffea000697ffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   31.982970] flags: 0x2fffc0000000000()
[   31.986849] raw: 02fffc0000000000 ffffea000697ffc8 ffffea000697ffc8 0000000000000000
[   31.994712] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   32.002574] page dumped because: kasan: bad access detected
[   32.008258] 
[   32.009882] Memory state around the buggy address:
[   32.014789]  ffff8801a5fffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   32.022127]  ffff8801a5ffff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   32.029467] >ffff8801a5ffff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   32.036801]                                                              ^
[   32.043792]  ffff8801a6000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   32.051140]  ffff8801a6000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   32.058476] ==================================================================
[   32.065888] Kernel panic - not syncing: panic_on_warn set ...
[   32.065888] 
[   32.073267] CPU: 1 PID: 4466 Comm: syz-executor480 Tainted: G    B             4.18.0-rc3+ #48
[   32.082010] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   32.091348] Call Trace:
[   32.093925]  dump_stack+0x1c9/0x2b4
[   32.097537]  ? dump_stack_print_info.cold.2+0x52/0x52
[   32.102731]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   32.107473]  panic+0x238/0x4e7
[   32.110646]  ? add_taint.cold.5+0x16/0x16
[   32.114788]  ? do_raw_spin_unlock+0xa7/0x2f0
[   32.119179]  ? do_raw_spin_unlock+0xa7/0x2f0
[   32.123571]  ? _copy_to_user+0xe9/0x110
[   32.127539]  kasan_end_report+0x47/0x4f
[   32.131503]  kasan_report.cold.7+0x76/0x2fe
[   32.135823]  check_memory_region+0x13e/0x1b0
[   32.140224]  kasan_check_read+0x11/0x20
[   32.144182]  _copy_to_user+0xe9/0x110
[   32.147969]  bpf_test_finish.isra.7+0xee/0x1f0
[   32.152532]  ? bpf_test_init.isra.8+0x100/0x100
[   32.157179]  ? bpf_test_run+0xc3/0x3b0
[   32.161051]  ? bpf_test_run+0x2fc/0x3b0
[   32.165017]  bpf_prog_test_run_skb+0x7d7/0xa30
[   32.169593]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   32.174420]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   32.179970]  ? __bpf_prog_get+0x9b/0x290
[   32.184045]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   32.188883]  bpf_prog_test_run+0x130/0x1a0
[   32.193105]  __x64_sys_bpf+0x3d8/0x510
[   32.196973]  ? bpf_prog_get+0x20/0x20
[   32.200757]  ? do_page_fault+0xf6/0x8c0
[   32.204715]  do_syscall_64+0x1b9/0x820
[   32.208588]  ? syscall_return_slowpath+0x5e0/0x5e0
[   32.213509]  ? syscall_return_slowpath+0x31d/0x5e0
[   32.218419]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   32.223415]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   32.228955]  ? prepare_exit_to_usermode+0x291/0x3b0
[   32.233959]  ? perf_trace_sys_enter+0xb10/0xb10
[   32.238611]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   32.243439]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   32.248619] RIP: 0033:0x4408d9
[   32.251784] 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 
[   32.270918] RSP: 002b:00007ffdf5c246e8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   32.278626] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   32.285895] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   32.293153] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
[   32.300402] R10: 0000000001053880 R11: 0000000000000213 R12: 0000000000401da0
[   32.307664] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   32.315442] Dumping ftrace buffer:
[   32.318979]    (ftrace buffer empty)
[   32.322666] Kernel Offset: disabled
[   32.326273] Rebooting in 86400 seconds..