[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   15.957174] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   17.748499] random: sshd: uninitialized urandom read (32 bytes read)
[   18.023137] random: sshd: uninitialized urandom read (32 bytes read)
[   18.745406] random: sshd: uninitialized urandom read (32 bytes read)
[   18.880782] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.22' (ECDSA) to the list of known hosts.
[   24.449432] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   24.544068] ==================================================================
[   24.551468] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   24.557778] Read of size 924 at addr ffff8801a6bffff2 by task syz-executor462/4468
[   24.565480] 
[   24.567094] CPU: 1 PID: 4468 Comm: syz-executor462 Not tainted 4.18.0-rc3+ #48
[   24.574432] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   24.583776] Call Trace:
[   24.586354]  dump_stack+0x1c9/0x2b4
[   24.589971]  ? dump_stack_print_info.cold.2+0x52/0x52
[   24.595144]  ? printk+0xa7/0xcf
[   24.598413]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   24.603161]  ? _copy_to_user+0xe9/0x110
[   24.607115]  print_address_description+0x6c/0x20b
[   24.611936]  ? _copy_to_user+0xe9/0x110
[   24.615889]  kasan_report.cold.7+0x242/0x2fe
[   24.620286]  check_memory_region+0x13e/0x1b0
[   24.624675]  kasan_check_read+0x11/0x20
[   24.628650]  _copy_to_user+0xe9/0x110
[   24.632448]  bpf_test_finish.isra.7+0xee/0x1f0
[   24.637014]  ? bpf_test_init.isra.8+0x100/0x100
[   24.641681]  ? bpf_test_run+0x1ea/0x3b0
[   24.645651]  ? bpf_test_run+0x2fc/0x3b0
[   24.649703]  bpf_prog_test_run_skb+0x7d7/0xa30
[   24.654277]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   24.659115]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   24.664637]  ? __bpf_prog_get+0x9b/0x290
[   24.668681]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   24.673506]  bpf_prog_test_run+0x130/0x1a0
[   24.677727]  __x64_sys_bpf+0x3d8/0x510
[   24.681598]  ? bpf_prog_get+0x20/0x20
[   24.685382]  ? do_page_fault+0xf6/0x8c0
[   24.689338]  do_syscall_64+0x1b9/0x820
[   24.693227]  ? syscall_return_slowpath+0x5e0/0x5e0
[   24.698154]  ? syscall_return_slowpath+0x31d/0x5e0
[   24.703075]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   24.708081]  ? prepare_exit_to_usermode+0x291/0x3b0
[   24.713085]  ? perf_trace_sys_enter+0xb10/0xb10
[   24.717739]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   24.722568]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   24.727736] RIP: 0033:0x440269
[   24.730899] 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 
[   24.750048] RSP: 002b:00007ffe5ea722a8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   24.757747] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   24.765003] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   24.772269] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   24.779547] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   24.786797] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   24.794050] 
[   24.795655] The buggy address belongs to the page:
[   24.800568] page:ffffea00069affc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   24.808703] flags: 0x2fffc0000000000()
[   24.812572] raw: 02fffc0000000000 ffffea00069affc8 ffffea00069affc8 0000000000000000
[   24.820432] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   24.828289] page dumped because: kasan: bad access detected
[   24.833971] 
[   24.835573] Memory state around the buggy address:
[   24.840493]  ffff8801a6bffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   24.847832]  ffff8801a6bfff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   24.855167] >ffff8801a6bfff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   24.862507]                                                              ^
[   24.869506]  ffff8801a6c00000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   24.876846]  ffff8801a6c00080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   24.884185] ==================================================================
[   24.891607] Kernel panic - not syncing: panic_on_warn set ...
[   24.891607] 
[   24.898975] CPU: 1 PID: 4468 Comm: syz-executor462 Tainted: G    B             4.18.0-rc3+ #48
[   24.907708] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   24.917143] Call Trace:
[   24.919728]  dump_stack+0x1c9/0x2b4
[   24.923351]  ? dump_stack_print_info.cold.2+0x52/0x52
[   24.928531]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   24.933281]  panic+0x238/0x4e7
[   24.936472]  ? add_taint.cold.5+0x16/0x16
[   24.940615]  ? do_raw_spin_unlock+0xa7/0x2f0
[   24.945014]  ? do_raw_spin_unlock+0xa7/0x2f0
[   24.949418]  ? _copy_to_user+0xe9/0x110
[   24.953378]  kasan_end_report+0x47/0x4f
[   24.957348]  kasan_report.cold.7+0x76/0x2fe
[   24.961653]  check_memory_region+0x13e/0x1b0
[   24.966047]  kasan_check_read+0x11/0x20
[   24.970008]  _copy_to_user+0xe9/0x110
[   24.973794]  bpf_test_finish.isra.7+0xee/0x1f0
[   24.978364]  ? bpf_test_init.isra.8+0x100/0x100
[   24.983020]  ? bpf_test_run+0x1ea/0x3b0
[   24.986982]  ? bpf_test_run+0x2fc/0x3b0
[   24.990953]  bpf_prog_test_run_skb+0x7d7/0xa30
[   24.995631]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   25.000464]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   25.006079]  ? __bpf_prog_get+0x9b/0x290
[   25.010125]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   25.014948]  bpf_prog_test_run+0x130/0x1a0
[   25.019268]  __x64_sys_bpf+0x3d8/0x510
[   25.023142]  ? bpf_prog_get+0x20/0x20
[   25.026935]  ? do_page_fault+0xf6/0x8c0
[   25.030895]  do_syscall_64+0x1b9/0x820
[   25.034782]  ? syscall_return_slowpath+0x5e0/0x5e0
[   25.039710]  ? syscall_return_slowpath+0x31d/0x5e0
[   25.044621]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   25.049616]  ? prepare_exit_to_usermode+0x291/0x3b0
[   25.054624]  ? perf_trace_sys_enter+0xb10/0xb10
[   25.059289]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   25.064126]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   25.069294] RIP: 0033:0x440269
[   25.072460] 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 
[   25.091858] RSP: 002b:00007ffe5ea722a8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   25.099543] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   25.106791] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   25.114049] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   25.121311] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   25.128657] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   25.136411] Dumping ftrace buffer:
[   25.139933]    (ftrace buffer empty)
[   25.143628] Kernel Offset: disabled
[   25.147233] Rebooting in 86400 seconds..