Add recursion depth protection to LIKE matching.

Since MatchText() recurses, it could in principle be driven to stack
overflow, although quite a long pattern would be needed.

diff --git a/src/backend/utils/adt/like.c b/src/backend/utils/adt/like.c
index 605204528e46cf12c0e3fdb4e98577b6ae880025..5b8c55ebaeba940eb9f7f877dca092fca303a1fe 100644 (file)
--- a/src/backend/utils/adt/like.c
+++ b/src/backend/utils/adt/like.c
@@ -21,6 +21,7 @@
 
 #include "catalog/pg_collation.h"
 #include "mb/pg_wchar.h"
+#include "miscadmin.h"
 #include "utils/builtins.h"
 #include "utils/pg_locale.h"
 

diff --git a/src/backend/utils/adt/like_match.c b/src/backend/utils/adt/like_match.c
index 0c20cd173e573c01c3653b66c7976fee7a4dbe8e..640f8f2014e543e0cac20fe496b724d821a23afe 100644 (file)
--- a/src/backend/utils/adt/like_match.c
+++ b/src/backend/utils/adt/like_match.c
@@ -83,6 +83,9 @@ MatchText(char *t, int tlen, char *p, int plen,
    if (plen == 1 && *p == '%')
        return LIKE_TRUE;
 
+   /* Since this function recurses, it could be driven to stack overflow */
+   check_stack_depth();
+
    /*
     * In this loop, we advance by char when matching wildcards (and thus on
     * recursive entry to this function we are properly char-synced). On other