This changes adds a fix for an unused variable issue in gnulib.
It is a part of a security series [1].

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

Signed-off-by: Marta Rybczynska <marta.rybczynska@...>
---
...ulib-regexec-Resolve-unused-variable.patch | 59 +++++++++++++++++++
meta/recipes-bsp/grub/grub2.inc | 1 +
2 files changed, 60 insertions(+)
create mode 100644 meta/recipes-bsp/grub/files/0008-gnulib-regexec-Resolve-unused-variable.patch

diff --git a/meta/recipes-bsp/grub/files/0008-gnulib-regexec-Resolve-unused-variable.patch b/meta/recipes-bsp/grub/files/0008-gnulib-regexec-Resolve-unused-variable.patch
new file mode 100644
index 0000000000..74ffb559e9
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/0008-gnulib-regexec-Resolve-unused-variable.patch
@@ -0,0 +1,59 @@
+From 9d36bce5d516b6379ba3a0dd1a94a9c035838827 Mon Sep 17 00:00:00 2001
+From: Darren Kenny <darren.kenny@...>
+Date: Wed, 21 Oct 2020 14:41:27 +0000
+Subject: [PATCH] gnulib/regexec: Resolve unused variable
+
+This is a really minor issue where a variable is being assigned to but
+not checked before it is overwritten again.
+
+The reason for this issue is that we are not building with DEBUG set and
+this in turn means that the assert() that reads the value of the
+variable match_last is being processed out.
+
+The solution, move the assignment to match_last in to an ifdef DEBUG too.
+
+Fixes: CID 292459
+
+Signed-off-by: Darren Kenny <darren.kenny@...>
+Reviewed-by: Daniel Kiper <daniel.kiper@...>
+
+Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=a983d36bd9178d377d2072fd4b11c635fdc404b4]
+Signed-off-by: Marta Rybczynska <marta.rybczynska@...>
+---
+ conf/Makefile.extra-dist | 1 +
+ .../lib/gnulib-patches/fix-unused-value.patch | 14 ++++++++++++++
+ 2 files changed, 15 insertions(+)
+ create mode 100644 grub-core/lib/gnulib-patches/fix-unused-value.patch
+
+diff --git a/conf/Makefile.extra-dist b/conf/Makefile.extra-dist
+index 46c4e95..9b01152 100644
+--- a/conf/Makefile.extra-dist
++++ b/conf/Makefile.extra-dist
+@@ -29,6 +29,7 @@ EXTRA_DIST += grub-core/genemuinit.sh
+ EXTRA_DIST += grub-core/genemuinitheader.sh
+
+ EXTRA_DIST += grub-core/lib/gnulib-patches/fix-null-deref.patch
++EXTRA_DIST += grub-core/lib/gnulib-patches/fix-unused-value.patch
+ EXTRA_DIST += grub-core/lib/gnulib-patches/fix-width.patch
+ EXTRA_DIST += grub-core/lib/gnulib-patches/no-abort.patch
+
+diff --git a/grub-core/lib/gnulib-patches/fix-unused-value.patch b/grub-core/lib/gnulib-patches/fix-unused-value.patch
+new file mode 100644
+index 0000000..ba51f1b
+--- /dev/null
++++ b/grub-core/lib/gnulib-patches/fix-unused-value.patch
+@@ -0,0 +1,14 @@
++--- a/lib/regexec.c 2020-10-21 14:25:35.310195912 +0000
+++++ b/lib/regexec.c 2020-10-21 14:32:07.961765604 +0000
++@@ -828,7 +828,11 @@
++ break;
++ if (__glibc_unlikely (err != REG_NOMATCH))
++ goto free_return;
+++#ifdef DEBUG
+++ /* Only used for assertion below when DEBUG is set, otherwise
+++ it will be over-written when we loop around. */
++ match_last = -1;
+++#endif
++ }
++ else
++ break; /* We found a match. */
diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc
index 46d65d8609..d2a1502d56 100644
--- a/meta/recipes-bsp/grub/grub2.inc
+++ b/meta/recipes-bsp/grub/grub2.inc
@@ -54,6 +54,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
file://0005-efi-Fix-some-malformed-device-path-arithmetic-errors.patch \
file://0006-kern-efi-Fix-memory-leak-on-failure.patch \
file://0007-kern-efi-mm-Fix-possible-NULL-pointer-dereference.patch \
+ file://0008-gnulib-regexec-Resolve-unused-variable.patch \
"
SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"
--
2.33.0