fix rejection of dns responses with pointers past 512 byte offset

[musl] / src / process / execvp.c

diff --git a/src/process/execvp.c b/src/process/execvp.c
index b2da44b..ef3b9dd 100644 (file)
--- a/src/process/execvp.c
+++ b/src/process/execvp.c
@@ -4,16 +4,19 @@
 #include <errno.h>
 #include <limits.h>
 
-int execvp(const char *file, char *const argv[])
+extern char **__environ;
+
+int __execvpe(const char *file, char *const argv[], char *const envp[])
 {
        const char *p, *z, *path = getenv("PATH");
        size_t l, k;
+       int seen_eacces = 0;
 
        errno = ENOENT;
        if (!*file) return -1;
 
        if (strchr(file, '/'))
-               return execv(file, argv);
+               return execve(file, argv, envp);
 
        if (!path) path = "/usr/local/bin:/bin:/usr/bin";
        k = strnlen(file, NAME_MAX+1);
@@ -25,8 +28,7 @@ int execvp(const char *file, char *const argv[])
 
        for(p=path; ; p=z) {
                char b[l+k+1];
-               z = strchr(p, ':');
-               if (!z) z = p+strlen(p);
+               z = __strchrnul(p, ':');
                if (z-p >= l) {
                        if (!*z++) break;
                        continue;
@@ -34,9 +36,25 @@ int execvp(const char *file, char *const argv[])
                memcpy(b, p, z-p);
                b[z-p] = '/';
                memcpy(b+(z-p)+(z>p), file, k+1);
-               execv(b, argv);
-               if (errno != ENOENT) return -1;
+               execve(b, argv, envp);
+               switch (errno) {
+               case EACCES:
+                       seen_eacces = 1;
+               case ENOENT:
+               case ENOTDIR:
+                       break;
+               default:
+                       return -1;
+               }
                if (!*z++) break;
        }
+       if (seen_eacces) errno = EACCES;
        return -1;
 }
+
+int execvp(const char *file, char *const argv[])
+{
+       return __execvpe(file, argv, __environ);
+}
+
+weak_alias(__execvpe, execvpe);