Fix #2889 - Fix use after free in rnum

radareorg · Jul 8, 2015 · 61eb7d3 · 61eb7d3 · XVilka · Jul 8, 2015
1 parent 41d12ff
commit 61eb7d3
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Showing 2 changed files with 13 additions and 6 deletions.
diff --git a/libr/core/core.c b/libr/core/core.c
@@ -141,13 +141,16 @@ static ut64 num_callback(RNum *userptr, const char *str, int *ok) {
 		}
 		// push state
 		{
-			if (str[1]) {
+			if (str[0] && str[1]) {
+				const char *q;
 				char *o = strdup (str+1);
-				const char *q = r_num_calc_index (core->num, NULL);
-				r_str_replace_char (o, ']', 0);
-				n = r_num_math (core->num, o);
-				r_num_calc_index (core->num, q);
-				free (o);
+				if (o) {
+					q = r_num_calc_index (core->num, NULL);
+					r_str_replace_char (o, ']', 0);
+					n = r_num_math (core->num, o);
+					r_num_calc_index (core->num, q);
+					free (o);
+				}
 			}
 		}
 		// pop state

diff --git a/libr/util/calc.c b/libr/util/calc.c
@@ -151,6 +151,10 @@ R_API const char *r_num_calc_index (RNum *num, const char *p) {
 		num->nc.calc_buf = p;
 		num->nc.calc_len = strlen (p);
 		num->nc.calc_i = 0;
+	} else {
+		num->nc.calc_buf = NULL;
+		num->nc.calc_len = 0;
+		num->nc.calc_i = 0;
 	}
 	//if (num->nc.calc_i>num->nc.calc_len) return NULL;
 	return num->nc.calc_buf + num->nc.calc_i;