[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   15.939206] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   20.168800] random: sshd: uninitialized urandom read (32 bytes read)
[   20.528169] random: sshd: uninitialized urandom read (32 bytes read)
[   21.243543] random: sshd: uninitialized urandom read (32 bytes read)
[   21.375603] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.61' (ECDSA) to the list of known hosts.
[   26.834452] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   26.932404] ==================================================================
[   26.939812] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   26.946110] Read of size 924 at addr ffff8801b97ffff2 by task syz-executor139/4470
[   26.953792] 
[   26.955407] CPU: 0 PID: 4470 Comm: syz-executor139 Not tainted 4.18.0-rc3+ #48
[   26.962753] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   26.972107] Call Trace:
[   26.974693]  dump_stack+0x1c9/0x2b4
[   26.978316]  ? dump_stack_print_info.cold.2+0x52/0x52
[   26.983489]  ? printk+0xa7/0xcf
[   26.986750]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   26.991500]  ? _copy_to_user+0xe9/0x110
[   26.995459]  print_address_description+0x6c/0x20b
[   27.000295]  ? _copy_to_user+0xe9/0x110
[   27.004263]  kasan_report.cold.7+0x242/0x2fe
[   27.008656]  check_memory_region+0x13e/0x1b0
[   27.013049]  kasan_check_read+0x11/0x20
[   27.017009]  _copy_to_user+0xe9/0x110
[   27.020809]  bpf_test_finish.isra.7+0xee/0x1f0
[   27.025389]  ? bpf_test_init.isra.8+0x100/0x100
[   27.030044]  ? bpf_test_run+0x2fc/0x3b0
[   27.034004]  bpf_prog_test_run_skb+0x7d7/0xa30
[   27.038573]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   27.043402]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   27.048925]  ? __bpf_prog_get+0x9b/0x290
[   27.052990]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   27.057819]  bpf_prog_test_run+0x130/0x1a0
[   27.062042]  __x64_sys_bpf+0x3d8/0x510
[   27.065912]  ? bpf_prog_get+0x20/0x20
[   27.069697]  ? do_page_fault+0xf6/0x8c0
[   27.073668]  do_syscall_64+0x1b9/0x820
[   27.077547]  ? syscall_slow_exit_work+0x500/0x500
[   27.082372]  ? syscall_return_slowpath+0x5e0/0x5e0
[   27.087283]  ? syscall_return_slowpath+0x31d/0x5e0
[   27.092210]  ? prepare_exit_to_usermode+0x291/0x3b0
[   27.097208]  ? perf_trace_sys_enter+0xb10/0xb10
[   27.101877]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   27.106703]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   27.111873] RIP: 0033:0x440269
[   27.115046] 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 
[   27.134183] RSP: 002b:00007fff342042d8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   27.141888] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   27.149143] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   27.156396] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   27.163649] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   27.170901] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   27.178157] 
[   27.179769] The buggy address belongs to the page:
[   27.184796] page:ffffea0006e5ffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x1
[   27.192917] flags: 0x2fffc0000000000()
[   27.196791] raw: 02fffc0000000000 dead000000000100 dead000000000200 0000000000000000
[   27.204775] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
[   27.212630] page dumped because: kasan: bad access detected
[   27.218311] 
[   27.219914] Memory state around the buggy address:
[   27.224832]  ffff8801b97ffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   27.232169]  ffff8801b97fff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   27.239508] >ffff8801b97fff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   27.246843]                                                              ^
[   27.253834]  ffff8801b9800000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   27.261188]  ffff8801b9800080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   27.268524] ==================================================================
[   27.275947] Kernel panic - not syncing: panic_on_warn set ...
[   27.275947] 
[   27.283314] CPU: 0 PID: 4470 Comm: syz-executor139 Tainted: G    B             4.18.0-rc3+ #48
[   27.292046] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   27.301390] Call Trace:
[   27.303978]  dump_stack+0x1c9/0x2b4
[   27.307588]  ? dump_stack_print_info.cold.2+0x52/0x52
[   27.312772]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   27.317513]  panic+0x238/0x4e7
[   27.320710]  ? add_taint.cold.5+0x16/0x16
[   27.324843]  ? do_raw_spin_unlock+0xa7/0x2f0
[   27.329248]  ? do_raw_spin_unlock+0xa7/0x2f0
[   27.333640]  ? _copy_to_user+0xe9/0x110
[   27.337600]  kasan_end_report+0x47/0x4f
[   27.341572]  kasan_report.cold.7+0x76/0x2fe
[   27.345880]  check_memory_region+0x13e/0x1b0
[   27.350287]  kasan_check_read+0x11/0x20
[   27.354253]  _copy_to_user+0xe9/0x110
[   27.358048]  bpf_test_finish.isra.7+0xee/0x1f0
[   27.362621]  ? bpf_test_init.isra.8+0x100/0x100
[   27.367290]  ? bpf_test_run+0x2fc/0x3b0
[   27.371260]  bpf_prog_test_run_skb+0x7d7/0xa30
[   27.375832]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   27.380664]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   27.386183]  ? __bpf_prog_get+0x9b/0x290
[   27.390232]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   27.395058]  bpf_prog_test_run+0x130/0x1a0
[   27.399286]  __x64_sys_bpf+0x3d8/0x510
[   27.403153]  ? bpf_prog_get+0x20/0x20
[   27.406937]  ? do_page_fault+0xf6/0x8c0
[   27.410893]  do_syscall_64+0x1b9/0x820
[   27.414765]  ? syscall_slow_exit_work+0x500/0x500
[   27.419589]  ? syscall_return_slowpath+0x5e0/0x5e0
[   27.424523]  ? syscall_return_slowpath+0x31d/0x5e0
[   27.429461]  ? prepare_exit_to_usermode+0x291/0x3b0
[   27.434475]  ? perf_trace_sys_enter+0xb10/0xb10
[   27.439132]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   27.443971]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   27.449140] RIP: 0033:0x440269
[   27.452309] 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 
[   27.471454] RSP: 002b:00007fff342042d8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   27.479148] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   27.486399] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   27.493673] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   27.500923] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   27.508173] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   27.515942] Dumping ftrace buffer:
[   27.519491]    (ftrace buffer empty)
[   27.523178] Kernel Offset: disabled
[   27.526795] Rebooting in 86400 seconds..