Change FILENAME_MAX to be only 255. Max filename on ext2 is 255,

so there is no reason to allocate 4k.  Change working of execvep.c
per patch from Matthias Kilian <kili@outback.escape.de> so that there
is not a fixed 127 byte buffer.  Too easy to overflow...
 -Erik

1 files changed, 31 insertions, 28 deletions

diff --git a/libc/unistd/execvep.c b/libc/unistd/execvep.c
index 4ac7692e9..6cd8cbaf9 100644
--- a/libc/unistd/execvep.c
+++ b/libc/unistd/execvep.c
@@ -1,43 +1,46 @@
-
 #include <unistd.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 
 int execvep(const char *path, char *__const argv[], char *__const envp[])
 {
-	if (!strchr(path, '/')) {
-		char partial[128];
-		char *p = getenv("PATH");
-		char *p2;
-
-		if (!p)
-			p = "/bin:/usr/bin";
+    if (!strchr(path, '/')) {
+	char *p = getenv("PATH");
 
-		for (; p && *p;) {
+	if (!p)
+	    p = "/bin:/usr/bin";
 
-			strcpy(partial, p);
+	for (; p && *p;) {
+	    char partial[FILENAME_MAX];
+	    char *p2;
 
-			p2 = strchr(partial, ':');
-			if (p2)
-				*p2 = '\0';
+	    p2 = strchr(p, ':');
+	    if (p2) {
+		size_t len = p2 - p;
+		strncpy(partial, p, len);
+		partial[len] = 0;
+	    } else {
+		strcpy(partial, p);
+	    }
 
-			if (strlen(partial))
-				strcat(partial, "/");
-			strcat(partial, path);
+	    if (strlen(partial))
+		strcat(partial, "/");
+	    strcat(partial, path);
 
-			execve(partial, argv, envp);
+	    execve(partial, argv, envp);
 
-			if (errno != ENOENT)
-				return -1;
-
-			p2 = strchr(p, ':');
-			if (p2)
-				p = p2 + 1;
-			else
-				p = 0;
-		}
+	    if (errno != ENOENT)
 		return -1;
-	} else
-		return execve(path, argv, envp);
+
+	    if (p2) {
+		p = p2 + 1;
+	    } else {
+		p = 0;
+	    }
+	}
+	return -1;
+    } else
+	return execve(path, argv, envp);
 }