[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   16.037957] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   19.687449] random: sshd: uninitialized urandom read (32 bytes read)
[   20.094552] random: sshd: uninitialized urandom read (32 bytes read)
[   20.795112] random: sshd: uninitialized urandom read (32 bytes read)
[   23.158926] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.39' (ECDSA) to the list of known hosts.
[   28.811048] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   28.922204] ==================================================================
[   28.930044] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   28.936617] Read of size 1012 at addr ffff8801bcbffff2 by task syz-executor319/4463
[   28.944597] 
[   28.946958] CPU: 1 PID: 4463 Comm: syz-executor319 Not tainted 4.18.0-rc3+ #48
[   28.954316] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   28.963672] Call Trace:
[   28.966294]  dump_stack+0x1c9/0x2b4
[   28.970117]  ? dump_stack_print_info.cold.2+0x52/0x52
[   28.975311]  ? printk+0xa7/0xcf
[   28.978650]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   28.983431]  ? _copy_to_user+0xe9/0x110
[   28.987596]  print_address_description+0x6c/0x20b
[   28.992459]  ? _copy_to_user+0xe9/0x110
[   28.996442]  kasan_report.cold.7+0x242/0x2fe
[   29.000860]  check_memory_region+0x13e/0x1b0
[   29.005265]  kasan_check_read+0x11/0x20
[   29.009250]  _copy_to_user+0xe9/0x110
[   29.013050]  bpf_test_finish.isra.7+0xee/0x1f0
[   29.017643]  ? bpf_test_init.isra.8+0x100/0x100
[   29.022323]  ? bpf_test_run+0xc3/0x3b0
[   29.026303]  ? bpf_test_run+0x2fc/0x3b0
[   29.030291]  bpf_prog_test_run_skb+0x7d7/0xa30
[   29.034891]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   29.039751]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   29.045411]  ? __bpf_prog_get+0x9b/0x290
[   29.049492]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   29.054353]  bpf_prog_test_run+0x130/0x1a0
[   29.058587]  __x64_sys_bpf+0x3d8/0x510
[   29.062482]  ? bpf_prog_get+0x20/0x20
[   29.066294]  ? do_page_fault+0xf6/0x8c0
[   29.070290]  do_syscall_64+0x1b9/0x820
[   29.074178]  ? syscall_return_slowpath+0x5e0/0x5e0
[   29.079111]  ? syscall_return_slowpath+0x31d/0x5e0
[   29.084051]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   29.089068]  ? prepare_exit_to_usermode+0x291/0x3b0
[   29.094082]  ? perf_trace_sys_enter+0xb10/0xb10
[   29.098753]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   29.103600]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.108784] RIP: 0033:0x440269
[   29.112054] 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 
[   29.131277] RSP: 002b:00007ffe13a8ece8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   29.139258] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   29.146527] RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a
[   29.153823] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   29.161089] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   29.168440] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   29.175710] 
[   29.177332] The buggy address belongs to the page:
[   29.182258] page:ffffea0006f2ffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x1
[   29.190571] flags: 0x2fffc0000000000()
[   29.194552] raw: 02fffc0000000000 dead000000000100 dead000000000200 0000000000000000
[   29.202440] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
[   29.210315] page dumped because: kasan: bad access detected
[   29.216021] 
[   29.217643] Memory state around the buggy address:
[   29.222582]  ffff8801bcbffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   29.230113]  ffff8801bcbfff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   29.237467] >ffff8801bcbfff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   29.244923]                                                              ^
[   29.251932]  ffff8801bcc00000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   29.259302]  ffff8801bcc00080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   29.267389] ==================================================================
[   29.274849] Kernel panic - not syncing: panic_on_warn set ...
[   29.274849] 
[   29.282217] CPU: 1 PID: 4463 Comm: syz-executor319 Tainted: G    B             4.18.0-rc3+ #48
[   29.290953] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   29.300677] Call Trace:
[   29.303267]  dump_stack+0x1c9/0x2b4
[   29.306906]  ? dump_stack_print_info.cold.2+0x52/0x52
[   29.312110]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   29.316865]  panic+0x238/0x4e7
[   29.320063]  ? add_taint.cold.5+0x16/0x16
[   29.324211]  ? do_raw_spin_unlock+0xa7/0x2f0
[   29.328650]  ? do_raw_spin_unlock+0xa7/0x2f0
[   29.333061]  ? _copy_to_user+0xe9/0x110
[   29.337044]  kasan_end_report+0x47/0x4f
[   29.341020]  kasan_report.cold.7+0x76/0x2fe
[   29.345773]  check_memory_region+0x13e/0x1b0
[   29.350236]  kasan_check_read+0x11/0x20
[   29.354256]  _copy_to_user+0xe9/0x110
[   29.358058]  bpf_test_finish.isra.7+0xee/0x1f0
[   29.362640]  ? bpf_test_init.isra.8+0x100/0x100
[   29.367309]  ? bpf_test_run+0xc3/0x3b0
[   29.371202]  ? bpf_test_run+0x2fc/0x3b0
[   29.375178]  bpf_prog_test_run_skb+0x7d7/0xa30
[   29.379762]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   29.384699]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   29.390242]  ? __bpf_prog_get+0x9b/0x290
[   29.394575]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   29.399421]  bpf_prog_test_run+0x130/0x1a0
[   29.403666]  __x64_sys_bpf+0x3d8/0x510
[   29.407647]  ? bpf_prog_get+0x20/0x20
[   29.411450]  ? do_page_fault+0xf6/0x8c0
[   29.415431]  do_syscall_64+0x1b9/0x820
[   29.419610]  ? syscall_return_slowpath+0x5e0/0x5e0
[   29.424537]  ? syscall_return_slowpath+0x31d/0x5e0
[   29.430422]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   29.435445]  ? prepare_exit_to_usermode+0x291/0x3b0
[   29.440462]  ? perf_trace_sys_enter+0xb10/0xb10
[   29.445139]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   29.450417]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.455619] RIP: 0033:0x440269
[   29.458999] 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 
[   29.478138] RSP: 002b:00007ffe13a8ece8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   29.486189] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   29.493550] RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a
[   29.500823] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   29.508096] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   29.515555] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   29.523319] Dumping ftrace buffer:
[   29.526869]    (ftrace buffer empty)
[   29.530597] Kernel Offset: disabled
[   29.534251] Rebooting in 86400 seconds..