[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   15.445866] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.
[   15.739650] random: sshd: uninitialized urandom read (32 bytes read)
[   15.890759] random: sshd: uninitialized urandom read (32 bytes read)
[   16.574531] random: sshd: uninitialized urandom read (32 bytes read)

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   16.710498] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.62' (ECDSA) to the list of known hosts.
[   22.135540] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   22.232718] ==================================================================
[   22.240142] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   22.246468] Read of size 1006 at addr ffff8801a6fffff2 by task syz-executor153/4459
[   22.254258] 
[   22.255870] CPU: 0 PID: 4459 Comm: syz-executor153 Not tainted 4.18.0-rc3+ #48
[   22.263212] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   22.272564] Call Trace:
[   22.275159]  dump_stack+0x1c9/0x2b4
[   22.278790]  ? dump_stack_print_info.cold.2+0x52/0x52
[   22.283978]  ? printk+0xa7/0xcf
[   22.287241]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   22.291985]  ? _copy_to_user+0xe9/0x110
[   22.295955]  print_address_description+0x6c/0x20b
[   22.300798]  ? _copy_to_user+0xe9/0x110
[   22.305500]  kasan_report.cold.7+0x242/0x2fe
[   22.309924]  check_memory_region+0x13e/0x1b0
[   22.314317]  kasan_check_read+0x11/0x20
[   22.318289]  _copy_to_user+0xe9/0x110
[   22.322076]  bpf_test_finish.isra.7+0xee/0x1f0
[   22.326648]  ? bpf_test_init.isra.8+0x100/0x100
[   22.331299]  ? bpf_test_run+0xc3/0x3b0
[   22.335175]  ? bpf_test_run+0xed/0x3b0
[   22.339163]  ? bpf_test_run+0x2fc/0x3b0
[   22.343137]  bpf_prog_test_run_skb+0x7d7/0xa30
[   22.347734]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   22.352581]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   22.358144]  ? __bpf_prog_get+0x9b/0x290
[   22.362198]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   22.367046]  bpf_prog_test_run+0x130/0x1a0
[   22.371284]  __x64_sys_bpf+0x3d8/0x510
[   22.375154]  ? bpf_prog_get+0x20/0x20
[   22.378989]  ? do_page_fault+0xf6/0x8c0
[   22.382975]  do_syscall_64+0x1b9/0x820
[   22.386850]  ? syscall_return_slowpath+0x5e0/0x5e0
[   22.391774]  ? syscall_return_slowpath+0x31d/0x5e0
[   22.396794]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   22.401837]  ? prepare_exit_to_usermode+0x291/0x3b0
[   22.406866]  ? perf_trace_sys_enter+0xb10/0xb10
[   22.411638]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   22.416495]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   22.421681] RIP: 0033:0x440319
[   22.424857] 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 
[   22.444018] RSP: 002b:00007ffeb9114388 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   22.451722] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440319
[   22.458993] RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a
[   22.466261] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   22.473515] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ba0
[   22.480785] R13: 0000000000401c30 R14: 0000000000000000 R15: 0000000000000000
[   22.488044] 
[   22.489695] The buggy address belongs to the page:
[   22.494620] page:ffffea00069bffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   22.502745] flags: 0x2fffc0000000000()
[   22.506634] raw: 02fffc0000000000 ffffea00069bffc8 ffffea00069bffc8 0000000000000000
[   22.514514] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   22.522372] page dumped because: kasan: bad access detected
[   22.528058] 
[   22.529673] Memory state around the buggy address:
[   22.534582]  ffff8801a6fffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   22.541928]  ffff8801a6ffff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   22.549280] >ffff8801a6ffff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   22.556627]                                                              ^
[   22.563637]  ffff8801a7000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   22.570984]  ffff8801a7000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   22.578330] ==================================================================
[   22.585953] Kernel panic - not syncing: panic_on_warn set ...
[   22.585953] 
[   22.593340] CPU: 0 PID: 4459 Comm: syz-executor153 Tainted: G    B             4.18.0-rc3+ #48
[   22.602071] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   22.611418] Call Trace:
[   22.613998]  dump_stack+0x1c9/0x2b4
[   22.617624]  ? dump_stack_print_info.cold.2+0x52/0x52
[   22.622796]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   22.627543]  panic+0x238/0x4e7
[   22.630726]  ? add_taint.cold.5+0x16/0x16
[   22.634854]  ? do_raw_spin_unlock+0xa7/0x2f0
[   22.639250]  ? do_raw_spin_unlock+0xa7/0x2f0
[   22.643662]  ? _copy_to_user+0xe9/0x110
[   22.647619]  kasan_end_report+0x47/0x4f
[   22.651578]  kasan_report.cold.7+0x76/0x2fe
[   22.655885]  check_memory_region+0x13e/0x1b0
[   22.660279]  kasan_check_read+0x11/0x20
[   22.664239]  _copy_to_user+0xe9/0x110
[   22.668035]  bpf_test_finish.isra.7+0xee/0x1f0
[   22.672617]  ? bpf_test_init.isra.8+0x100/0x100
[   22.677278]  ? bpf_test_run+0xc3/0x3b0
[   22.681157]  ? bpf_test_run+0xed/0x3b0
[   22.685038]  ? bpf_test_run+0x2fc/0x3b0
[   22.689006]  bpf_prog_test_run_skb+0x7d7/0xa30
[   22.693580]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   22.698419]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   22.703954]  ? __bpf_prog_get+0x9b/0x290
[   22.708006]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   22.712849]  bpf_prog_test_run+0x130/0x1a0
[   22.717076]  __x64_sys_bpf+0x3d8/0x510
[   22.720943]  ? bpf_prog_get+0x20/0x20
[   22.724734]  ? do_page_fault+0xf6/0x8c0
[   22.728689]  do_syscall_64+0x1b9/0x820
[   22.732571]  ? syscall_return_slowpath+0x5e0/0x5e0
[   22.737495]  ? syscall_return_slowpath+0x31d/0x5e0
[   22.742403]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   22.747407]  ? prepare_exit_to_usermode+0x291/0x3b0
[   22.752407]  ? perf_trace_sys_enter+0xb10/0xb10
[   22.757073]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   22.761907]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   22.767076] RIP: 0033:0x440319
[   22.770249] 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 
[   22.789372] RSP: 002b:00007ffeb9114388 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   22.797072] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440319
[   22.804327] RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a
[   22.811577] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   22.818828] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ba0
[   22.826088] R13: 0000000000401c30 R14: 0000000000000000 R15: 0000000000000000
[   22.833855] Dumping ftrace buffer:
[   22.837377]    (ftrace buffer empty)
[   22.841070] Kernel Offset: disabled
[   22.844674] Rebooting in 86400 seconds..