Comment 4 for bug 1580385

It has been brought to my attention that 'nmap -sV' randomly segfault in Xenial.
I was also able to reproduce the situation.

It seems to be caused by a stack exhaustion due to a hascaptures() being called over and over.

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Reading symbols from /usr/bin/nmap...(no debugging symbols found)...done.
[New LWP 17917]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `nmap -sV <IP_ADDRESS>'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f8e05b3f257 in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
(gdb) bt
#0 0x00007f8e05b3f257 in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#1 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#2 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#3 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#4 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#5 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#6 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#7 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#8 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#9 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#10 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#11 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#12 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#13 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
#14 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
....
#161459 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
......
#354107 0x00007f8e05b3f25c in hascaptures () from /usr/lib/x86_64-linux-gnu/liblua5.2-lpeg.so.2
...

0x00007f8e05b3f253 <+51>: lea 0x8(%rbx),%rdi
=> 0x00007f8e05b3f257 <+55>: callq 0x7f8e05b3f220 <hascaptures>
0x00007f8e05b3f25c <+60>: test %eax,%eax