Store temporaries in the request pool for regexes compiled per-request.

The code for testing regexes with embedded Apache variables
(rule->re_precomp == 1) during request processing was utilizing the global
engine pool for the storage of temporary values. This approach is not
threadsafe, retains the temporary variables longer than they are usable,
and causes corruption of the global pool's "cleanups" linked-lists when
Apache is configured with a threaded MPM.

Author: lightsey

apache2/re_operators.c

@@ -784,10 +784,10 @@ static int msre_op_validateHash_execute(modsec_rec *msr, msre_rule *rule, msre_v
                 msr_log(msr, 6, "Escaping pattern [%s]",pattern);
             }
 
-            regex = msc_pregcomp_ex(rule->ruleset->mp, pattern, PCRE_DOTALL | PCRE_DOLLAR_ENDONLY, &errptr, 
+            regex = msc_pregcomp_ex(msr->mp, pattern, PCRE_DOTALL | PCRE_DOLLAR_ENDONLY, &errptr,
                     &erroffset, msc_pcre_match_limit, msc_pcre_match_limit_recursion);
             if (regex == NULL) {
-                *error_msg = apr_psprintf(rule->ruleset->mp, "Error compiling pattern (offset %d): %s",
+                *error_msg = apr_psprintf(msr->mp, "Error compiling pattern (offset %d): %s",
                         erroffset, errptr);
                 return 0;
             }
@@ -797,7 +797,7 @@ static int msre_op_validateHash_execute(modsec_rec *msr, msre_rule *rule, msre_v
             if (msr->txcfg->debuglog_level >= 4) {
                 rc = msc_fullinfo(regex, PCRE_INFO_JIT, &jit);
                 if ((rc != 0) || (jit != 1)) {
-                    *error_msg = apr_psprintf(rule->ruleset->mp,
+                    *error_msg = apr_psprintf(msr->mp,
                             "Rule %pp [id \"%s\"][file \"%s\"][line \"%d\"] - "
                             "Execution error - "
                             "Does not support JIT (%d)",
@@ -1018,9 +1018,9 @@ static int msre_op_rx_execute(modsec_rec *msr, msre_rule *rule, msre_var *var, c
                 msr_log(msr, 6, "Escaping pattern [%s]",pattern);
             }
 
-            regex = msc_pregcomp_ex(rule->ruleset->mp, pattern, PCRE_DOTALL | PCRE_DOLLAR_ENDONLY, &errptr, &erroffset, msc_pcre_match_limit, msc_pcre_match_limit_recursion);
+            regex = msc_pregcomp_ex(msr->mp, pattern, PCRE_DOTALL | PCRE_DOLLAR_ENDONLY, &errptr, &erroffset, msc_pcre_match_limit, msc_pcre_match_limit_recursion);
             if (regex == NULL) {
-                *error_msg = apr_psprintf(rule->ruleset->mp, "Error compiling pattern (offset %d): %s",
+                *error_msg = apr_psprintf(msr->mp, "Error compiling pattern (offset %d): %s",
                         erroffset, errptr);
                 return 0;
             }
@@ -1030,7 +1030,7 @@ static int msre_op_rx_execute(modsec_rec *msr, msre_rule *rule, msre_var *var, c
             if (msr->txcfg->debuglog_level >= 4) {
                 rc = msc_fullinfo(regex, PCRE_INFO_JIT, &jit);
                 if ((rc != 0) || (jit != 1)) {
-                    *error_msg = apr_psprintf(rule->ruleset->mp,
+                    *error_msg = apr_psprintf(msr->mp,
                             "Rule %pp [id \"%s\"][file \"%s\"][line \"%d\"] - "
                             "Execution error - "
                             "Does not support JIT (%d)",