pcreposix segfault in regfree with trivial program

[markpizz (Mark Pizzolato)]

This program (retest.c) fails:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <pcreposix.h>
#include <pcre.h>
#include <pthread.h>

int main (int argc, char **argv)
    {
    int re_result;
    regex_t re;
    char match_buf[64] = "Match This";

    printf("Using PCRE V %s\n", pcre_version());
    memset (&re, 0, sizeof(re));
    re_result = regcomp (&re, match_buf, REG_EXTENDED);
    if (re_result)
        {
        size_t err_size = regerror (re_result, &re, NULL, 0);
        char *err_buf = (char *)calloc (err_size+1, 1);

        regerror (re_result, &re, err_buf, err_size);
        fprintf (stderr, "Regular Expression Error compiling '%s': %s\n", match_buf, err_buf);
        free (err_buf);
        exit (1);
        }
    printf("Regular Expression compile of '%s' successful\n", match_buf);
    regfree (&re);
    }

This is how I see the failure:

bash-3.2# port list installed
bash-3.2# port install pcre
--->  Computing dependencies for pcre
The following dependencies will be installed: 
 bzip2
 libedit
 ncurses
 zlib
Continue? [Y/n]: y
--->  Fetching archive for bzip2
--->  Attempting to fetch bzip2-1.0.6_0.darwin_17.x86_64.tbz2 from https://packages.macports.org/bzip2
--->  Attempting to fetch bzip2-1.0.6_0.darwin_17.x86_64.tbz2.rmd160 from https://packages.macports.org/bzip2
--->  Installing bzip2 @1.0.6_0
--->  Activating bzip2 @1.0.6_0
--->  Cleaning bzip2
--->  Fetching archive for ncurses
--->  Attempting to fetch ncurses-6.1_0.darwin_17.x86_64.tbz2 from https://packages.macports.org/ncurses
--->  Attempting to fetch ncurses-6.1_0.darwin_17.x86_64.tbz2.rmd160 from https://packages.macports.org/ncurses
--->  Installing ncurses @6.1_0
--->  Activating ncurses @6.1_0
--->  Cleaning ncurses
--->  Fetching archive for libedit
--->  Attempting to fetch libedit-20170329-3.1_2.darwin_17.x86_64.tbz2 from https://packages.macports.org/libedit
--->  Attempting to fetch libedit-20170329-3.1_2.darwin_17.x86_64.tbz2.rmd160 from https://packages.macports.org/libedit
--->  Installing libedit @20170329-3.1_2
--->  Activating libedit @20170329-3.1_2
--->  Cleaning libedit
--->  Fetching archive for zlib
--->  Attempting to fetch zlib-1.2.11_0.darwin_17.x86_64.tbz2 from https://packages.macports.org/zlib
--->  Attempting to fetch zlib-1.2.11_0.darwin_17.x86_64.tbz2.rmd160 from https://packages.macports.org/zlib
--->  Installing zlib @1.2.11_0
--->  Activating zlib @1.2.11_0
--->  Cleaning zlib
--->  Fetching archive for pcre
--->  Attempting to fetch pcre-8.42_0.darwin_17.x86_64.tbz2 from https://packages.macports.org/pcre
--->  Attempting to fetch pcre-8.42_0.darwin_17.x86_64.tbz2.rmd160 from https://packages.macports.org/pcre
--->  Installing pcre @8.42_0
--->  Activating pcre @8.42_0
--->  Cleaning pcre
--->  Updating database of binaries
--->  Updating database of C++ stdlib usage              
--->  Scanning binaries for linking errors
--->  No broken files found.
--->  No broken ports found.
bash-3.2# exit
exit
mac-mini:~ mark$ gcc retest.c -I/opt/local/include -L/opt/local/lib  -lpthread -lpcreposix -lpcre -o retest
mac-mini:~ mark$ ./retest
Using PCRE V 8.42 2018-03-20
Regular Expression compile of 'Match This' successful
Segmentation fault: 11
-mini:~ mark$ 

[jmroot (Joshua Root)]

Can you attach a crash log?

[markpizz (Mark Pizzolato)]

Hi Larry,

My system is running the latest macOS Hight Sierra version 10.13.6.

Looking in /Library/Logs/DiagnosticReports I do not see any 'crash log' specific to this simple application generating a segfault. The /Library/Logs/CrashReporter directory is empty.

If I run this test program under the debugger I get:

marks-mac-mini:simh mark$ gcc -g -O0 retest.c -I/opt/local/include -L/opt/local/lib  -lpthread -lpcreposix -lpcre -o retest 
marks-mac-mini:simh mark$ lldb ./retest
(lldb) target create "./retest"
Current executable set to './retest' (x86_64).
(lldb) run
Process 20418 launched: './retest' (x86_64)
Using PCRE V 8.42 2018-03-20
Regular Expression compile of 'Match This' successful
Process 20418 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x400280)
    frame #0: 0x00007fff714ece95 libsystem_c.dylib`tre_free + 37
libsystem_c.dylib`tre_free:
->  0x7fff714ece95 <+37>: cmpl   $0x0, 0x40(%r14)
    0x7fff714ece9a <+42>: movq   (%r14), %rdi
    0x7fff714ece9d <+45>: je     0x7fff714ecef6            ; <+134>
    0x7fff714ece9f <+47>: xorl   %ebx, %ebx
Target 0: (retest) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x400280)
  * frame #0: 0x00007fff714ece95 libsystem_c.dylib`tre_free + 37
    frame #1: 0x0000000100000dfd retest`main(argc=1, argv=0x00007ffeefbffb48) at retest.c:29
    frame #2: 0x00007fff7142a015 libdyld.dylib`start + 1
    frame #3: 0x00007fff7142a015 libdyld.dylib`start + 1
(lldb) 

[dgilman (David Gilman)]

I can't reproduce this in the latest pcre v8.44.