Use a stack buffer for the validate_env_vars() error message.

diff --git a/plugins/sudoers/env.c b/plugins/sudoers/env.c
index 64020a6e3be0fb5d8cb66e34cb986f0aa1d6f758..17953af2569065524a1ffd9649fed16942e56ea6 100644 (file)
--- a/plugins/sudoers/env.c
+++ b/plugins/sudoers/env.c
@@ -1083,8 +1083,7 @@ bool
 validate_env_vars(char * const env_vars[])
 {
     char * const *ep;
-    char *eq, *bad = NULL;
-    size_t len, blen = 0, bsize = 0;
+    char *eq, errbuf[4096];
     bool okvar, rval = true;
     debug_decl(validate_env_vars, SUDOERS_DEBUG_ENV)
 
@@ -1092,6 +1091,7 @@ validate_env_vars(char * const env_vars[])
        debug_return_bool(true);        /* nothing to do */
 
     /* Add user-specified environment variables. */
+    errbuf[0] = '\0';
     for (ep = env_vars; *ep != NULL; ep++) {
        if (def_secure_path && !user_is_exempt() &&
            strncmp(*ep, "PATH=", 5) == 0) {
@@ -1105,27 +1105,20 @@ validate_env_vars(char * const env_vars[])
            /* Not allowed, add to error string, allocating as needed. */
            if ((eq = strchr(*ep, '=')) != NULL)
                *eq = '\0';
-           len = strlen(*ep) + 2;
-           if (blen + len >= bsize) {
-               do {
-                   bsize += 1024;
-               } while (blen + len >= bsize);
-               bad = sudo_erealloc(bad, bsize);
-               bad[blen] = '\0';
+           if (errbuf[0] != '\0')
+               (void)strlcat(errbuf, ", ", sizeof(errbuf));
+           if (strlcat(errbuf, *ep, sizeof(errbuf)) >= sizeof(errbuf)) {
+               errbuf[sizeof(errbuf) - 4] = '\0';
+               (void)strlcat(errbuf, "...", sizeof(errbuf));
            }
-           strlcat(bad, *ep, bsize);
-           strlcat(bad, ", ", bsize);
-           blen += len;
            if (eq != NULL)
                *eq = '=';
        }
     }
-    if (bad != NULL) {
-       bad[blen - 2] = '\0';           /* remove trailing ", " */
+    if (errbuf[0] != '\0') {
        /* XXX - audit? */
        log_warningx(0,
-           N_("sorry, you are not allowed to set the following environment variables: %s"), bad);
-       sudo_efree(bad);
+           N_("sorry, you are not allowed to set the following environment variables: %s"), errbuf);
        rval = false;
     }
     debug_return_bool(rval);