From: Darren Kenny <darren.kenny@oracle.com>
Date: Fri, 19 Feb 2021 17:12:23 +0000 (+0000)
Subject: net/tftp: Fix dangling memory pointer
X-Git-Tag: grub-2.06-rc1~124
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0cb838b281a68b536a09681f9557ea6a7ac5da7a;p=thirdparty%2Fgrub.git

net/tftp: Fix dangling memory pointer

The static code analysis tool, Parfait, reported that the valid of
file->data was left referencing memory that was freed by the call to
grub_free(data) where data was initialized from file->data.

To ensure that there is no unintentional access to this memory
referenced by file->data we should set the pointer to NULL.

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---

diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
index 7e659a78b..1f3793ed8 100644
--- a/grub-core/net/tftp.c
+++ b/grub-core/net/tftp.c
@@ -442,6 +442,7 @@ tftp_close (struct grub_file *file)
       grub_net_udp_close (data->sock);
     }
   grub_free (data);
+  file->data = NULL;
   return GRUB_ERR_NONE;
 }