qga-win: prevent crash when executing guest-file-read with large count

[thirdparty/qemu.git] / qemu-bridge-helper.c

diff --git a/qemu-bridge-helper.c b/qemu-bridge-helper.c
index 95624bc30055b9b5628e6cf495989b0f2ebb66d3..88b26747fc866116637716264dea3ce4631a4b11 100644 (file)
--- a/qemu-bridge-helper.c
+++ b/qemu-bridge-helper.c
@@ -43,7 +43,7 @@
 
 #include "net/tap-linux.h"
 
-#ifdef CONFIG_LIBCAP
+#ifdef CONFIG_LIBCAP_NG
 #include <cap-ng.h>
 #endif
 
@@ -102,9 +102,7 @@ static int parse_acl_file(const char *filename, ACLList *acl_list)
 
         if (arg == NULL) {
             fprintf(stderr, "Invalid config line:\n  %s\n", line);
-            fclose(f);
-            errno = EINVAL;
-            return -1;
+            goto err;
         }
 
         *arg = 0;
@@ -119,6 +117,11 @@ static int parse_acl_file(const char *filename, ACLList *acl_list)
         }
         *argend = 0;
 
+        if (!g_str_equal(cmd, "include") && strlen(arg) >= IFNAMSIZ) {
+            fprintf(stderr, "name `%s' too long: %zu\n", arg, strlen(arg));
+            goto err;
+        }
+
         if (strcmp(cmd, "deny") == 0) {
             acl_rule = g_malloc(sizeof(*acl_rule));
             if (strcmp(arg, "all") == 0) {
@@ -142,15 +145,18 @@ static int parse_acl_file(const char *filename, ACLList *acl_list)
             parse_acl_file(arg, acl_list);
         } else {
             fprintf(stderr, "Unknown command `%s'\n", cmd);
-            fclose(f);
-            errno = EINVAL;
-            return -1;
+            goto err;
         }
     }
 
     fclose(f);
-
     return 0;
+
+err:
+    fclose(f);
+    errno = EINVAL;
+    return -1;
+
 }
 
 static bool has_vnet_hdr(int fd)
@@ -201,7 +207,7 @@ static int send_fd(int c, int fd)
     return sendmsg(c, &msg, 0);
 }
 
-#ifdef CONFIG_LIBCAP
+#ifdef CONFIG_LIBCAP_NG
 static int drop_privileges(void)
 {
     /* clear all capabilities */
@@ -240,7 +246,7 @@ int main(int argc, char **argv)
     int access_allowed, access_denied;
     int ret = EXIT_SUCCESS;
 
-#ifdef CONFIG_LIBCAP
+#ifdef CONFIG_LIBCAP_NG
     /* if we're run from an suid binary, immediately drop privileges preserving
      * cap_net_admin */
     if (geteuid() == 0 && getuid() != geteuid()) {
@@ -269,6 +275,10 @@ int main(int argc, char **argv)
         usage();
         return EXIT_FAILURE;
     }
+    if (strlen(bridge) >= IFNAMSIZ) {
+        fprintf(stderr, "name `%s' too long: %zu\n", bridge, strlen(bridge));
+        return EXIT_FAILURE;
+    }
 
     /* parse default acl file */
     QSIMPLEQ_INIT(&acl_list);