From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Mark Salter <msalter@redhat.com>

Date: Tue, 22 Aug 2017 12:21:12 -0400

Subject: [PATCH] Fix grub_net_hwaddr_to_str

commit 5c3b78c92f8 introduced support for larger network hw addresses.

However, grub_net_hwaddr_to_str() relies on GRUB_NET_MAX_STR_ADDRESS_SIZE

to prevent a spurious ':' at the end of the string. So now, if actual

hwaddr size is less than max, an extra ':' appears at the end of the

string. So calculate max string size based on actual hwaddr length to

fix the problem.

Signed-off-by: Mark Salter <msalter@redhat.com>

---

 grub-core/net/net.c | 4 +++-

 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/grub-core/net/net.c b/grub-core/net/net.c

index a0f4d00f0be..191e8e41bd6 100644

--- a/grub-core/net/net.c

+++ b/grub-core/net/net.c

@@ -770,6 +770,7 @@ grub_net_hwaddr_to_str (const grub_net_link_level_address_t *addr, char *str)

 {

   char *ptr;

   unsigned i;

+  int maxstr;

   if (addr->len > GRUB_NET_MAX_LINK_ADDRESS_SIZE)

     {

@@ -778,9 +779,10 @@ grub_net_hwaddr_to_str (const grub_net_link_level_address_t *addr, char *str)

 		    addr->type, addr->len);

        return;

     }

+  maxstr = addr->len * grub_strlen ("XX:");

   for (ptr = str, i = 0; i < addr->len; i++)

     {

-      ptr += grub_snprintf (ptr, GRUB_NET_MAX_STR_HWADDR_LEN - (ptr - str),

+      ptr += grub_snprintf (ptr, maxstr - (ptr - str),

 		     "%02x:", addr->mac[i] & 0xff);

     }

 }