enforce lenght limit and catch out-ouf-memory conditions

diff --git a/ext/standard/levenshtein.c b/ext/standard/levenshtein.c
index 080c86a3271c12138c4dbd7c8de6fb8fa2ae9b88..5052dadd56ea1cdd7c35820ba088b6938863f505 100644 (file)
--- a/ext/standard/levenshtein.c
+++ b/ext/standard/levenshtein.c
@@ -23,6 +23,8 @@
 #include <ctype.h>
 #include "php_string.h"
 
+#define LEVENSHTEIN_MAX_LENTH 255
+
 /* reference implementation, only optimized for memory usage, not speed */
 static int reference_levdist(const char *s1, int l1, 
                                                                                                                 const char *s2, int l2, 
@@ -34,8 +36,16 @@ static int reference_levdist(const char *s1, int l1,
        if(l1==0) return l2*cost_ins;
        if(l2==0) return l1*cost_del;
 
-       p1=malloc(l2*sizeof(int));
-       p2=malloc(l2*sizeof(int));
+       if((l1>LEVENSHTEIN_MAX_LENTH)||(l2>LEVENSHTEIN_MAX_LENTH))
+               return -1;
+
+       if(!(p1=emalloc(l2*sizeof(int)))) {
+               return -2;
+       }
+       if(!(p2=emalloc(l2*sizeof(int)))) {
+               free(p1);
+               return -2;
+       }
 
        p1[0]=(s1[0]==s2[0])?0:cost_rep;
 
@@ -57,8 +67,8 @@ static int reference_levdist(const char *s1, int l1,
 
        c0=p1[l2-1];
 
-       free(p1);
-       free(p2);
+       efree(p1);
+       efree(p2);
 
        return c0;
 }