grub: add a fix for a memory leak

This patch adds a fix for a memory leak in grub's loader/xnu.
It is a part of a security series [1].

[1] https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00007.html

(From OE-Core rev: b53db9013a0f4b3a2a91ec6e5c39d939f388749c)

Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-bsp/grub/files/0038-loader-xnu-Fix-memory-leak.patch

@@ -0,0 +1,38 @@
+From 0a4aa7c16f65cdfaa1013f0796afa929f8d6dc1a Mon Sep 17 00:00:00 2001
+From: Darren Kenny <darren.kenny@oracle.com>
+Date: Thu, 26 Nov 2020 12:53:10 +0000
+Subject: [PATCH] loader/xnu: Fix memory leak
+
+The code here is finished with the memory stored in name, but it only
+frees it if there curvalue is valid, while it could actually free it
+regardless.
+
+The fix is a simple relocation of the grub_free() to before the test
+of curvalue.
+
+Fixes: CID 96646
+
+Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=bcb59ece3263d118510c4440c4da0950f224bb7f]
+Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
+---
+ grub-core/loader/xnu.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/grub-core/loader/xnu.c b/grub-core/loader/xnu.c
+index 07232d2..b3029a8 100644
+--- a/grub-core/loader/xnu.c
++++ b/grub-core/loader/xnu.c
+@@ -1388,9 +1388,9 @@ grub_xnu_fill_devicetree (void)
+     name[len] = 0;
+ 
+     curvalue = grub_xnu_create_value (curkey, name);
++    grub_free (name);
+     if (!curvalue)
+       return grub_errno;
+-    grub_free (name);
+    
+     data = grub_malloc (grub_strlen (var->value) + 1);
+     if (!data)

meta/recipes-bsp/grub/grub2.inc

@@ -84,6 +84,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
            file://0035-video-readers-jpeg-Test-for-an-invalid-next-marker-r.patch \
            file://0036-gfxmenu-gui_list-Remove-code-that-coverity-is-flaggi.patch \
            file://0037-loader-bsd-Check-for-NULL-arg-up-front.patch \
+           file://0038-loader-xnu-Fix-memory-leak.patch \
            "
 SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
 SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"