[05/17] Regex: Avoid memory leaks.
Commit Message
This patch avoids possible memory leaks if errors are encountered
while compiling a regular expression.
2017-11-27 Arnold D. Robbins <arnold@skeeve.com>
* posix/regex_internal.c (re_dfa_add_node): Avoid memory leaks.
* posix/regcomp.c (build_range_exp): Ditto.
(build_charclass_op): Ditto.
Comments
On 12/08/2017 01:16 AM, Arnold Robbins wrote:
> + if (new_array_start != NULL)
> + re_free(new_array_start);
For this rarely-used code, it's better to omit the first line and simply
call re_free unconditionally, as this is simpler and likely will make
for fewer instructions in the executable. re_free will do the right
thing if new_array_start is NULL.
Aside from that, this patch is essentially the same as:
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=9e849a708308b73064cd965de022d357e3abda80
which is already installed in Gnulib.
@@ -2699,7 +2699,14 @@ build_range_exp (bitset_t sbcset, bracket_elem_t *start_elem,
new_nranges);
if (BE (new_array_start == NULL || new_array_end == NULL, 0))
+ {
+ /* if one is not NULL, free it to avoid leaks */
+ if (new_array_start != NULL)
+ re_free(new_array_start);
+ if (new_array_end != NULL)
+ re_free(new_array_end);
return REG_ESPACE;
+ }
mbcset->range_starts = new_array_start;
mbcset->range_ends = new_array_end;
@@ -3604,6 +3611,13 @@ build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
if (BE (sbcset == NULL, 0))
#endif /* not RE_ENABLE_I18N */
{
+ /* if one is not NULL, free it to avoid leaks */
+ if (sbcset != NULL)
+ free(sbcset);
+#ifdef RE_ENABLE_I18N
+ if (mbcset != NULL)
+ free(mbcset);
+#endif
*err = REG_ESPACE;
return NULL;
}
@@ -1423,7 +1423,18 @@ re_dfa_add_node (re_dfa_t *dfa, re_token_t token)
new_eclosures = re_realloc (dfa->eclosures, re_node_set, new_nodes_alloc);
if (BE (new_nexts == NULL || new_indices == NULL
|| new_edests == NULL || new_eclosures == NULL, 0))
+ {
+ /* if any are not NULL, free them, avoid leaks */
+ if (new_nexts != NULL)
+ re_free(new_nexts);
+ if (new_indices != NULL)
+ re_free(new_indices);
+ if (new_edests != NULL)
+ re_free(new_edests);
+ if (new_eclosures != NULL)
+ re_free(new_eclosures);
return -1;
+ }
dfa->nexts = new_nexts;
dfa->org_indices = new_indices;
dfa->edests = new_edests;