Fixed memory leak when using execvpe() with vfork().

diff --git a/third-party/execvpe/execvpe.c b/third-party/execvpe/execvpe.c
index 6ce1e9d814bd1cbe5db0e311209efe96239ca5a4..9e30ade0c0ec187316d5b90b317f2ed4c33f2da7 100644 (file)
--- a/third-party/execvpe/execvpe.c
+++ b/third-party/execvpe/execvpe.c
@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <alloca.h>
 
 /*
  * We want the search semantics of execvp, but we want to provide our
@@ -77,20 +78,23 @@ execvpe(char *name, char *const argv[], char **envp)
     if (!(path = getenv("PATH"))) {
 #ifdef HAVE_CONFSTR
         ln = confstr(_CS_PATH, NULL, 0);
-        if ((cur = path = malloc(ln + 1)) != NULL) {
+        if ((cur = path = alloca(ln + 1)) != NULL) {
            path[0] = ':';
            (void) confstr (_CS_PATH, path + 1, ln);
        }
 #else
-        if ((cur = path = malloc(1 + 1)) != NULL) {
+        if ((cur = path = alloca(1 + 1)) != NULL) {
            path[0] = ':';
            path[1] = '\0';
        }
 #endif
-    } else
-       cur = path = strdup(path);
+    } else {
+        cur = alloca(strlen(path) + 1);
+        strcpy(cur, path);
+        path = cur;
+    }
 
-    if (path == NULL || (bp = buf = malloc(strlen(path)+strlen(name)+2)) == NULL)
+    if (path == NULL || (bp = buf = alloca(strlen(path)+strlen(name)+2)) == NULL)
        goto done;
 
     while (cur != NULL) {
@@ -129,13 +133,12 @@ execvpe(char *name, char *const argv[], char **envp)
 
                for (cnt = 0, ap = (char **) argv; *ap; ++ap, ++cnt)
                    ;
-               if ((ap = malloc((cnt + 2) * sizeof(char *))) != NULL) {
+               if ((ap = alloca((cnt + 2) * sizeof(char *))) != NULL) {
                    memcpy(ap + 2, argv + 1, cnt * sizeof(char *));
 
                    ap[0] = "sh";
                    ap[1] = bp;
                    (void) execve("/bin/sh", ap, envp);
-                   free(ap);
                }
                goto done;
            }
@@ -152,10 +155,6 @@ execvpe(char *name, char *const argv[], char **envp)
     else if (!errno)
        errno = ENOENT;
   done:
-    if (path)
-       free(path);
-    if (buf)
-       free(buf);
     return (-1);
 }
 #endif