From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Mon, 9 Mar 2020 15:30:05 +0100
Subject: [PATCH] efi/ip4_config: Improve check to detect literal IPv6
 addresses

The grub_efi_string_to_ip4_address() function wrongly assumes that an IPv6
address is an IPv4 address, because it doesn't take into account the case
of a caller passing an IPv6 address as a string.

This leads to the grub_efi_net_parse_address() function to fail and print
the following error message:

error: net/efi/net.c:785:unrecognised network address '2000:dead:beef:a::1'

Resolves: rhbz#1811560

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---
 grub-core/net/efi/ip4_config.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/grub-core/net/efi/ip4_config.c b/grub-core/net/efi/ip4_config.c
index 38e2a04747a..6117e60ab12 100644
--- a/grub-core/net/efi/ip4_config.c
+++ b/grub-core/net/efi/ip4_config.c
@@ -56,9 +56,20 @@ int
 grub_efi_string_to_ip4_address (const char *val, grub_efi_ipv4_address_t *address, const char **rest)
 {
   grub_uint32_t newip = 0;
-  int i;
+  int i, ncolon = 0;
   const char *ptr = val;
 
+  /* Check that is not an IPv6 address */
+  for (i = 0; i < grub_strlen(ptr); i++)
+    {
+      if (ptr[i] == '[' && i == 0)
+        return 0;
+
+      if (ptr[i] == ':')
+          if (i == 0 || ++ncolon == 2)
+            return 0;
+    }
+
   for (i = 0; i < 4; i++)
     {
       unsigned long t;
