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 bcd9e2182d0907834f1788121d501035e83a6608..23c6d7b8cec448db3c377da10ffdf2a1e8b0acf9 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 1e5e00a468d1c4201ffd7196b5a2aa008e73cf7f..e0d11ddf88472e2b2f699f7f4a42aad8b040746e 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