[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   16.779512] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   21.536300] random: sshd: uninitialized urandom read (32 bytes read)
[   21.922466] random: sshd: uninitialized urandom read (32 bytes read)
[   22.622265] random: sshd: uninitialized urandom read (32 bytes read)
[   22.760493] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.0.13' (ECDSA) to the list of known hosts.
[   28.254760] random: sshd: uninitialized urandom read (32 bytes read)
executing program
executing program
executing program
[   44.703046] ==================================================================
[   44.710475] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   44.716803] Read of size 924 at addr ffff8801b6fffff2 by task syz-executor659/4527
[   44.724481] 
[   44.726091] CPU: 1 PID: 4527 Comm: syz-executor659 Not tainted 4.18.0-rc4-next-20180711+ #4
[   44.734561] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   44.743911] Call Trace:
[   44.746482]  dump_stack+0x1c9/0x2b4
[   44.750086]  ? dump_stack_print_info.cold.2+0x52/0x52
[   44.755254]  ? printk+0xa7/0xcf
[   44.758539]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   44.763276]  ? _copy_to_user+0xe9/0x110
[   44.767261]  print_address_description+0x6c/0x20b
[   44.772083]  ? _copy_to_user+0xe9/0x110
[   44.776041]  kasan_report.cold.7+0x242/0x30d
[   44.780443]  check_memory_region+0x13e/0x1b0
[   44.784835]  kasan_check_read+0x11/0x20
[   44.788788]  _copy_to_user+0xe9/0x110
[   44.792574]  bpf_test_finish.isra.7+0xee/0x1f0
[   44.797140]  ? bpf_test_init.isra.8+0x100/0x100
[   44.801791]  ? write_comp_data+0xa/0x70
[   44.805742]  ? bpf_test_run+0x2fc/0x3b0
[   44.809697]  bpf_prog_test_run_skb+0x7d7/0xa30
[   44.814257]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   44.819080]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   44.824594]  ? __bpf_prog_get+0x9b/0x290
[   44.828645]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   44.833464]  bpf_prog_test_run+0x130/0x1a0
[   44.837685]  __x64_sys_bpf+0x3d8/0x510
[   44.841558]  ? bpf_prog_get+0x20/0x20
[   44.845346]  ? do_page_fault+0xf6/0x8c0
[   44.849305]  do_syscall_64+0x1b9/0x820
[   44.853178]  ? syscall_return_slowpath+0x5e0/0x5e0
[   44.858087]  ? syscall_return_slowpath+0x31d/0x5e0
[   44.862995]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   44.867997]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   44.873519]  ? prepare_exit_to_usermode+0x291/0x3b0
[   44.878514]  ? perf_trace_sys_enter+0xb10/0xb10
[   44.883168]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   44.888007]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   44.893181] RIP: 0033:0x4408d9
[   44.896346] 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 
[   44.915461] RSP: 002b:00007ffe07613f98 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   44.923144] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   44.930389] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   44.937638] RBP: 0000000000000000 R08: 00000009004002c8 R09: 00000009004002c8
[   44.944884] R10: 0000000001a4d880 R11: 0000000000000213 R12: 0000000000008361
[   44.952128] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   44.959387] 
[   44.960988] The buggy address belongs to the page:
[   44.965895] page:ffffea0006dbffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x1
[   44.974015] flags: 0x2fffc0000000000()
[   44.977885] raw: 02fffc0000000000 dead000000000100 dead000000000200 0000000000000000
[   44.985744] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
[   44.993596] page dumped because: kasan: bad access detected
[   44.999279] 
[   45.000883] Memory state around the buggy address:
[   45.005786]  ffff8801b6fffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.013124]  ffff8801b6ffff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.020458] >ffff8801b6ffff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.027798]                                                              ^
[   45.034787]  ffff8801b7000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   45.042130]  ffff8801b7000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   45.049468] ==================================================================
[   45.057067] Kernel panic - not syncing: panic_on_warn set ...
[   45.057067] 
[   45.064435] CPU: 1 PID: 4527 Comm: syz-executor659 Tainted: G    B             4.18.0-rc4-next-20180711+ #4
[   45.074292] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   45.083631] Call Trace:
[   45.086211]  dump_stack+0x1c9/0x2b4
[   45.089818]  ? dump_stack_print_info.cold.2+0x52/0x52
[   45.094990]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   45.099730]  panic+0x238/0x4e7
[   45.102911]  ? add_taint.cold.5+0x16/0x16
[   45.107043]  ? do_raw_spin_unlock+0xa7/0x2f0
[   45.111428]  ? do_raw_spin_unlock+0xa7/0x2f0
[   45.115817]  ? _copy_to_user+0xe9/0x110
[   45.119769]  kasan_end_report+0x47/0x4f
[   45.123723]  kasan_report.cold.7+0x76/0x30d
[   45.128030]  check_memory_region+0x13e/0x1b0
[   45.132418]  kasan_check_read+0x11/0x20
[   45.136389]  _copy_to_user+0xe9/0x110
[   45.140171]  bpf_test_finish.isra.7+0xee/0x1f0
[   45.144731]  ? bpf_test_init.isra.8+0x100/0x100
[   45.149384]  ? write_comp_data+0xa/0x70
[   45.153339]  ? bpf_test_run+0x2fc/0x3b0
[   45.157301]  bpf_prog_test_run_skb+0x7d7/0xa30
[   45.161862]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   45.166684]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   45.172198]  ? __bpf_prog_get+0x9b/0x290
[   45.176238]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   45.181061]  bpf_prog_test_run+0x130/0x1a0
[   45.185281]  __x64_sys_bpf+0x3d8/0x510
[   45.189150]  ? bpf_prog_get+0x20/0x20
[   45.192932]  ? do_page_fault+0xf6/0x8c0
[   45.196886]  do_syscall_64+0x1b9/0x820
[   45.200754]  ? syscall_return_slowpath+0x5e0/0x5e0
[   45.205662]  ? syscall_return_slowpath+0x31d/0x5e0
[   45.210569]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   45.215579]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   45.221098]  ? prepare_exit_to_usermode+0x291/0x3b0
[   45.226098]  ? perf_trace_sys_enter+0xb10/0xb10
[   45.230752]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   45.235579]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   45.240754] RIP: 0033:0x4408d9
[   45.243925] 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 
[   45.263072] RSP: 002b:00007ffe07613f98 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   45.270762] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004408d9
[   45.278016] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 000000000000000a
[   45.285282] RBP: 0000000000000000 R08: 00000009004002c8 R09: 00000009004002c8
[   45.292531] R10: 0000000001a4d880 R11: 0000000000000213 R12: 0000000000008361
[   45.299778] R13: 0000000000401e30 R14: 0000000000000000 R15: 0000000000000000
[   45.307498] Dumping ftrace buffer:
[   45.311018]    (ftrace buffer empty)
[   45.314716] Kernel Offset: disabled
[   45.318330] Rebooting in 86400 seconds..