[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   15.614636] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.
[   16.359969] random: sshd: uninitialized urandom read (32 bytes read)
[   16.583901] random: sshd: uninitialized urandom read (32 bytes read)

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   17.261840] random: sshd: uninitialized urandom read (32 bytes read)
[   28.426120] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.36' (ECDSA) to the list of known hosts.
[   33.867838] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   33.950627] ==================================================================
[   33.958020] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   33.964317] Read of size 924 at addr ffff8801c53ffff2 by task syz-executor411/4455
[   33.971997] 
[   33.973610] CPU: 1 PID: 4455 Comm: syz-executor411 Not tainted 4.18.0-rc3+ #48
[   33.980950] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   33.990283] Call Trace:
[   33.992856]  dump_stack+0x1c9/0x2b4
[   33.996473]  ? dump_stack_print_info.cold.2+0x52/0x52
[   34.001643]  ? printk+0xa7/0xcf
[   34.004909]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   34.009656]  ? _copy_to_user+0xe9/0x110
[   34.013607]  print_address_description+0x6c/0x20b
[   34.018427]  ? _copy_to_user+0xe9/0x110
[   34.022379]  kasan_report.cold.7+0x242/0x2fe
[   34.026767]  check_memory_region+0x13e/0x1b0
[   34.031150]  kasan_check_read+0x11/0x20
[   34.035101]  _copy_to_user+0xe9/0x110
[   34.038880]  bpf_test_finish.isra.7+0xee/0x1f0
[   34.043440]  ? bpf_test_init.isra.8+0x100/0x100
[   34.048088]  ? bpf_test_run+0x2fc/0x3b0
[   34.052046]  bpf_prog_test_run_skb+0x7d7/0xa30
[   34.056613]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.061439]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   34.066954]  ? __bpf_prog_get+0x9b/0x290
[   34.071006]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.075828]  bpf_prog_test_run+0x130/0x1a0
[   34.080043]  __x64_sys_bpf+0x3d8/0x510
[   34.083905]  ? bpf_prog_get+0x20/0x20
[   34.087712]  ? do_page_fault+0xf6/0x8c0
[   34.091685]  do_syscall_64+0x1b9/0x820
[   34.095550]  ? syscall_return_slowpath+0x5e0/0x5e0
[   34.100455]  ? syscall_return_slowpath+0x31d/0x5e0
[   34.105363]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   34.110364]  ? prepare_exit_to_usermode+0x291/0x3b0
[   34.115362]  ? perf_trace_sys_enter+0xb10/0xb10
[   34.120010]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   34.124833]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   34.130000] RIP: 0033:0x440269
[   34.133163] 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 
[   34.152277] RSP: 002b:00007ffe8784b448 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   34.159962] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   34.167209] RDX: 0000000000000028 RSI: 0000000020000380 RDI: 000000000000000a
[   34.174457] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   34.181704] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   34.188950] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   34.196202] 
[   34.197803] The buggy address belongs to the page:
[   34.202710] page:ffffea000714ffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x1
[   34.210828] flags: 0x2fffc0000000000()
[   34.214698] raw: 02fffc0000000000 dead000000000100 dead000000000200 0000000000000000
[   34.222559] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
[   34.230413] page dumped because: kasan: bad access detected
[   34.236095] 
[   34.237695] Memory state around the buggy address:
[   34.242607]  ffff8801c53ffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   34.249941]  ffff8801c53fff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   34.257275] >ffff8801c53fff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   34.264608]                                                              ^
[   34.271597]  ffff8801c5400000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   34.280688]  ffff8801c5400080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   34.288018] ==================================================================
[   34.295438] Kernel panic - not syncing: panic_on_warn set ...
[   34.295438] 
[   34.302790] CPU: 1 PID: 4455 Comm: syz-executor411 Tainted: G    B             4.18.0-rc3+ #48
[   34.311518] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   34.320849] Call Trace:
[   34.323432]  dump_stack+0x1c9/0x2b4
[   34.327040]  ? dump_stack_print_info.cold.2+0x52/0x52
[   34.332212]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   34.336961]  panic+0x238/0x4e7
[   34.340132]  ? add_taint.cold.5+0x16/0x16
[   34.344346]  ? do_raw_spin_unlock+0xa7/0x2f0
[   34.348733]  ? do_raw_spin_unlock+0xa7/0x2f0
[   34.353121]  ? _copy_to_user+0xe9/0x110
[   34.357075]  kasan_end_report+0x47/0x4f
[   34.361033]  kasan_report.cold.7+0x76/0x2fe
[   34.365337]  check_memory_region+0x13e/0x1b0
[   34.369722]  kasan_check_read+0x11/0x20
[   34.373674]  _copy_to_user+0xe9/0x110
[   34.377454]  bpf_test_finish.isra.7+0xee/0x1f0
[   34.382013]  ? bpf_test_init.isra.8+0x100/0x100
[   34.386670]  ? bpf_test_run+0x2fc/0x3b0
[   34.390625]  bpf_prog_test_run_skb+0x7d7/0xa30
[   34.395185]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.400007]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   34.405520]  ? __bpf_prog_get+0x9b/0x290
[   34.409559]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   34.414376]  bpf_prog_test_run+0x130/0x1a0
[   34.418596]  __x64_sys_bpf+0x3d8/0x510
[   34.422465]  ? bpf_prog_get+0x20/0x20
[   34.426250]  ? do_page_fault+0xf6/0x8c0
[   34.430203]  do_syscall_64+0x1b9/0x820
[   34.434068]  ? syscall_return_slowpath+0x5e0/0x5e0
[   34.438975]  ? syscall_return_slowpath+0x31d/0x5e0
[   34.443897]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   34.448890]  ? prepare_exit_to_usermode+0x291/0x3b0
[   34.453885]  ? perf_trace_sys_enter+0xb10/0xb10
[   34.458532]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   34.463355]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   34.468521] RIP: 0033:0x440269
[   34.471688] 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 
[   34.490803] RSP: 002b:00007ffe8784b448 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   34.498490] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440269
[   34.505737] RDX: 0000000000000028 RSI: 0000000020000380 RDI: 000000000000000a
[   34.512980] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   34.520224] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401af0
[   34.527469] R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000
[   34.535127] Dumping ftrace buffer:
[   34.538654]    (ftrace buffer empty)
[   34.542353] Kernel Offset: disabled
[   34.545962] Rebooting in 86400 seconds..