[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   16.925229] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.
[   17.212720] random: sshd: uninitialized urandom read (32 bytes read)
[   17.465881] random: sshd: uninitialized urandom read (32 bytes read)

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   18.202632] random: sshd: uninitialized urandom read (32 bytes read)
[   18.336835] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.0.11' (ECDSA) to the list of known hosts.
[   23.827741] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   23.932184] ==================================================================
[   23.939585] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   23.945895] Read of size 1006 at addr ffff8801a73ffff2 by task syz-executor705/4472
[   23.953680] 
[   23.955299] CPU: 0 PID: 4472 Comm: syz-executor705 Not tainted 4.18.0-rc4-next-20180710+ #3
[   23.963764] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   23.973103] Call Trace:
[   23.975682]  dump_stack+0x1c9/0x2b4
[   23.979295]  ? dump_stack_print_info.cold.2+0x52/0x52
[   23.984488]  ? printk+0xa7/0xcf
[   23.987748]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   23.992500]  ? _copy_to_user+0xe9/0x110
[   23.996461]  print_address_description+0x6c/0x20b
[   24.001292]  ? _copy_to_user+0xe9/0x110
[   24.005262]  kasan_report.cold.7+0x242/0x30d
[   24.009678]  check_memory_region+0x13e/0x1b0
[   24.014082]  kasan_check_read+0x11/0x20
[   24.018040]  _copy_to_user+0xe9/0x110
[   24.021828]  bpf_test_finish.isra.7+0xee/0x1f0
[   24.026398]  ? bpf_test_init.isra.8+0x100/0x100
[   24.031059]  ? bpf_test_run+0xc3/0x3b0
[   24.034929]  ? bpf_test_run+0x2fc/0x3b0
[   24.038886]  bpf_prog_test_run_skb+0x7d7/0xa30
[   24.043450]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   24.048309]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   24.053830]  ? __bpf_prog_get+0x9b/0x290
[   24.057895]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   24.062727]  bpf_prog_test_run+0x130/0x1a0
[   24.066956]  __x64_sys_bpf+0x3d8/0x510
[   24.070824]  ? bpf_prog_get+0x20/0x20
[   24.074626]  ? do_page_fault+0xf6/0x8c0
[   24.078594]  do_syscall_64+0x1b9/0x820
[   24.082469]  ? syscall_return_slowpath+0x5e0/0x5e0
[   24.087386]  ? syscall_return_slowpath+0x31d/0x5e0
[   24.092301]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   24.097299]  ? prepare_exit_to_usermode+0x291/0x3b0
[   24.102302]  ? perf_trace_sys_enter+0xb10/0xb10
[   24.106953]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   24.111792]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   24.116988] RIP: 0033:0x440319
[   24.120157] 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 
[   24.139284] RSP: 002b:00007ffc88f4cc28 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   24.146994] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440319
[   24.154276] RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a
[   24.161532] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   24.168785] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ba0
[   24.176045] R13: 0000000000401c30 R14: 0000000000000000 R15: 0000000000000000
[   24.183330] 
[   24.184941] The buggy address belongs to the page:
[   24.189862] page:ffffea00069cffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   24.198000] flags: 0x2fffc0000000000()
[   24.201883] raw: 02fffc0000000000 ffffea00069cffc8 ffffea00069cffc8 0000000000000000
[   24.209759] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   24.217627] page dumped because: kasan: bad access detected
[   24.223323] 
[   24.224927] Memory state around the buggy address:
[   24.229836]  ffff8801a73ffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   24.237617]  ffff8801a73fff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   24.244990] >ffff8801a73fff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   24.252349]                                                              ^
[   24.259359]  ffff8801a7400000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   24.266703]  ffff8801a7400080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   24.274055] ==================================================================
[   24.281463] Kernel panic - not syncing: panic_on_warn set ...
[   24.281463] 
[   24.288831] CPU: 0 PID: 4472 Comm: syz-executor705 Tainted: G    B             4.18.0-rc4-next-20180710+ #3
[   24.298693] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   24.308041] Call Trace:
[   24.310628]  dump_stack+0x1c9/0x2b4
[   24.314242]  ? dump_stack_print_info.cold.2+0x52/0x52
[   24.319437]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   24.324185]  panic+0x238/0x4e7
[   24.327365]  ? add_taint.cold.5+0x16/0x16
[   24.331517]  ? do_raw_spin_unlock+0xa7/0x2f0
[   24.335925]  ? do_raw_spin_unlock+0xa7/0x2f0
[   24.340460]  ? _copy_to_user+0xe9/0x110
[   24.344425]  kasan_end_report+0x47/0x4f
[   24.348394]  kasan_report.cold.7+0x76/0x30d
[   24.352729]  check_memory_region+0x13e/0x1b0
[   24.357150]  kasan_check_read+0x11/0x20
[   24.361287]  _copy_to_user+0xe9/0x110
[   24.365077]  bpf_test_finish.isra.7+0xee/0x1f0
[   24.369663]  ? bpf_test_init.isra.8+0x100/0x100
[   24.374329]  ? bpf_test_run+0xc3/0x3b0
[   24.378200]  ? bpf_test_run+0x2fc/0x3b0
[   24.382160]  bpf_prog_test_run_skb+0x7d7/0xa30
[   24.386728]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   24.391575]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   24.397098]  ? __bpf_prog_get+0x9b/0x290
[   24.401156]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   24.405982]  bpf_prog_test_run+0x130/0x1a0
[   24.410205]  __x64_sys_bpf+0x3d8/0x510
[   24.414102]  ? bpf_prog_get+0x20/0x20
[   24.417894]  ? do_page_fault+0xf6/0x8c0
[   24.421853]  do_syscall_64+0x1b9/0x820
[   24.425733]  ? syscall_return_slowpath+0x5e0/0x5e0
[   24.430654]  ? syscall_return_slowpath+0x31d/0x5e0
[   24.435569]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   24.440570]  ? prepare_exit_to_usermode+0x291/0x3b0
[   24.445579]  ? perf_trace_sys_enter+0xb10/0xb10
[   24.450252]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   24.455083]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   24.460258] RIP: 0033:0x440319
[   24.463432] 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 
[   24.482579] RSP: 002b:00007ffc88f4cc28 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   24.490276] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440319
[   24.497632] RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a
[   24.504900] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   24.512162] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ba0
[   24.519421] R13: 0000000000401c30 R14: 0000000000000000 R15: 0000000000000000
[   24.527243] Dumping ftrace buffer:
[   24.530769]    (ftrace buffer empty)
[   24.534459] Kernel Offset: disabled
[   24.538069] Rebooting in 86400 seconds..