BUG/MINOR: pattern: a sample marked as const could be written

The functions add final 0 to string if the final 0 is not set,
but don't check the flag CONST. This patch duplicates the strings
if the final zero is not set and the string is CONST.

Should be backported until 2.2 (at least)

(cherry picked from commit a68affeaa9377f88f773ef62a9bb2541dfb672d3)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/src/pattern.c b/src/pattern.c
index 4a3fe29..8bdd4d9 100644 (file)
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -465,11 +465,18 @@ struct pattern *pat_match_str(struct sample *smp, struct pattern_expr *expr, int
 
                if (smp->data.u.str.data < smp->data.u.str.size) {
                        /* we may have to force a trailing zero on the test pattern and
-                        * the buffer is large enough to accommodate it.
+                        * the buffer is large enough to accommodate it. If the flag
+                        * CONST is set, duplicate the string
                         */
                        prev = smp->data.u.str.area[smp->data.u.str.data];
-                       if (prev)
-                               smp->data.u.str.area[smp->data.u.str.data] = '\0';
+                       if (prev) {
+                               if (smp->flags & SMP_F_CONST) {
+                                       if (!smp_dup(smp))
+                                               return NULL;
+                               } else {
+                                       smp->data.u.str.area[smp->data.u.str.data] = '\0';
+                               }
+                       }
                }
                else {
                        /* Otherwise, the sample is duplicated. A trailing zero