[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   19.810871] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.
[   20.431116] random: sshd: uninitialized urandom read (32 bytes read)
[   20.720212] random: sshd: uninitialized urandom read (32 bytes read)

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   21.555469] random: sshd: uninitialized urandom read (32 bytes read)
[   40.786169] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.1' (ECDSA) to the list of known hosts.
[   46.205676] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   46.307445] ==================================================================
[   46.314948] BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110
[   46.321262] Read of size 1080 at addr ffff8801a7bffff2 by task syz-executor861/4569
[   46.329030] 
[   46.330642] CPU: 0 PID: 4569 Comm: syz-executor861 Not tainted 4.18.0-rc3+ #3
[   46.337910] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   46.347242] Call Trace:
[   46.349832]  dump_stack+0x1c9/0x2b4
[   46.353455]  ? dump_stack_print_info.cold.2+0x52/0x52
[   46.358628]  ? printk+0xa7/0xcf
[   46.361889]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   46.366633]  ? _copy_to_user+0xe9/0x110
[   46.370592]  print_address_description+0x6c/0x20b
[   46.375431]  ? _copy_to_user+0xe9/0x110
[   46.379385]  kasan_report.cold.7+0x242/0x2fe
[   46.383779]  check_memory_region+0x13e/0x1b0
[   46.388170]  kasan_check_read+0x11/0x20
[   46.392126]  _copy_to_user+0xe9/0x110
[   46.395913]  bpf_test_finish.isra.7+0xee/0x1f0
[   46.400491]  ? bpf_test_init.isra.8+0x100/0x100
[   46.405157]  ? bpf_test_run+0x2fc/0x3b0
[   46.409120]  bpf_prog_test_run_skb+0x7d7/0xa30
[   46.413690]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   46.418521]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   46.424040]  ? __bpf_prog_get+0x9b/0x290
[   46.428096]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   46.432922]  bpf_prog_test_run+0x130/0x1a0
[   46.437142]  __x64_sys_bpf+0x3d8/0x510
[   46.441011]  ? bpf_prog_get+0x20/0x20
[   46.444813]  ? do_syscall_64+0x9a/0x820
[   46.448784]  do_syscall_64+0x1b9/0x820
[   46.452664]  ? syscall_return_slowpath+0x5e0/0x5e0
[   46.457577]  ? syscall_return_slowpath+0x31d/0x5e0
[   46.462496]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   46.467857]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   46.472688]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   46.477869] RIP: 0033:0x440259
[   46.481046] 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 
[   46.500218] RSP: 002b:00007ffd23574c88 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   46.507909] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440259
[   46.515159] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   46.522432] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   46.529686] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ae0
[   46.536937] R13: 0000000000401b70 R14: 0000000000000000 R15: 0000000000000000
[   46.544212] 
[   46.545822] The buggy address belongs to the page:
[   46.550734] page:ffffea00069effc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   46.558854] flags: 0x2fffc0000000000()
[   46.562726] raw: 02fffc0000000000 ffffea00069effc8 ffffea00069effc8 0000000000000000
[   46.570588] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   46.578444] page dumped because: kasan: bad access detected
[   46.584129] 
[   46.585734] Memory state around the buggy address:
[   46.590646]  ffff8801a7bffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   46.597987]  ffff8801a7bfff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   46.605336] >ffff8801a7bfff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   46.612684]                                                              ^
[   46.619694]  ffff8801a7c00000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   46.627034]  ffff8801a7c00080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   46.634369] ==================================================================
[   46.641704] Disabling lock debugging due to kernel taint
[   46.647211] Kernel panic - not syncing: panic_on_warn set ...
[   46.647211] 
[   46.654581] CPU: 0 PID: 4569 Comm: syz-executor861 Tainted: G    B             4.18.0-rc3+ #3
[   46.663219] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   46.672552] Call Trace:
[   46.675132]  dump_stack+0x1c9/0x2b4
[   46.678742]  ? dump_stack_print_info.cold.2+0x52/0x52
[   46.683930]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   46.688672]  panic+0x238/0x4e7
[   46.691859]  ? add_taint.cold.5+0x16/0x16
[   46.695987]  ? do_raw_spin_unlock+0xa7/0x2f0
[   46.700387]  ? do_raw_spin_unlock+0xa7/0x2f0
[   46.704779]  ? _copy_to_user+0xe9/0x110
[   46.708742]  kasan_end_report+0x47/0x4f
[   46.713045]  kasan_report.cold.7+0x76/0x2fe
[   46.717348]  check_memory_region+0x13e/0x1b0
[   46.721740]  kasan_check_read+0x11/0x20
[   46.725697]  _copy_to_user+0xe9/0x110
[   46.729482]  bpf_test_finish.isra.7+0xee/0x1f0
[   46.734051]  ? bpf_test_init.isra.8+0x100/0x100
[   46.738731]  ? bpf_test_run+0x2fc/0x3b0
[   46.742782]  bpf_prog_test_run_skb+0x7d7/0xa30
[   46.747344]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   46.752188]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   46.757705]  ? __bpf_prog_get+0x9b/0x290
[   46.761755]  ? bpf_test_finish.isra.7+0x1f0/0x1f0
[   46.766573]  bpf_prog_test_run+0x130/0x1a0
[   46.770785]  __x64_sys_bpf+0x3d8/0x510
[   46.774650]  ? bpf_prog_get+0x20/0x20
[   46.778431]  ? do_syscall_64+0x9a/0x820
[   46.782384]  do_syscall_64+0x1b9/0x820
[   46.786252]  ? syscall_return_slowpath+0x5e0/0x5e0
[   46.791184]  ? syscall_return_slowpath+0x31d/0x5e0
[   46.796093]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   46.801437]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   46.806258]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   46.811425] RIP: 0033:0x440259
[   46.814589] 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 
[   46.833729] RSP: 002b:00007ffd23574c88 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
[   46.841424] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440259
[   46.848672] RDX: 0000000000000028 RSI: 0000000020000180 RDI: 000000000000000a
[   46.855928] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
[   46.863173] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401ae0
[   46.870421] R13: 0000000000401b70 R14: 0000000000000000 R15: 0000000000000000
[   46.877733] Dumping ftrace buffer:
[   46.881248]    (ftrace buffer empty)
[   46.884933] Kernel Offset: disabled
[   46.888540] Rebooting in 86400 seconds..