grub: add a fix for a memory leak

This patch fixes a memory leak in grub's syslinux parsing. 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: a9d0155842f0582a0d247c81bf972661f0a2cda8)

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>

2 files changed, 44 insertions, 0 deletions

diff --git a/meta/recipes-bsp/grub/files/0028-syslinux-Fix-memory-leak-while-parsing.patch b/meta/recipes-bsp/grub/files/0028-syslinux-Fix-memory-leak-while-parsing.patch
new file mode 100644
index 0000000000..d8c21d88f7
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/0028-syslinux-Fix-memory-leak-while-parsing.patch
@@ -0,0 +1,43 @@
+From ea12feb69b6af93c7e2fa03df7ac3bd1f4edd599 Mon Sep 17 00:00:00 2001
+From: Darren Kenny <darren.kenny@oracle.com>
+Date: Thu, 26 Nov 2020 15:31:53 +0000
+Subject: [PATCH] syslinux: Fix memory leak while parsing
+
+In syslinux_parse_real() the 2 points where return is being called
+didn't release the memory stored in buf which is no longer required.
+
+Fixes: CID 176634
+
+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=95bc016dba94cab3d398dd74160665915cd08ad6]
+Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
+---
+ grub-core/lib/syslinux_parse.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/grub-core/lib/syslinux_parse.c b/grub-core/lib/syslinux_parse.c
+index 4afa992..3acc6b4 100644
+--- a/grub-core/lib/syslinux_parse.c
++++ b/grub-core/lib/syslinux_parse.c
+@@ -737,7 +737,10 @@ syslinux_parse_real (struct syslinux_menu *menu)
+                  && grub_strncasecmp ("help", ptr3, ptr4 - ptr3) == 0))
+            {
+              if (helptext (ptr5, file, menu))
+-               return 1;
++               {
++                 grub_free (buf);
++                 return 1;
++               }
+              continue;
+            }
+ 
+@@ -757,6 +760,7 @@ syslinux_parse_real (struct syslinux_menu *menu)
+     }
+  fail:
+   grub_file_close (file);
++  grub_free (buf);
+   return err;
+ }
+ 
diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc
index ef409bdd6a..c965f0fd15 100644
--- a/meta/recipes-bsp/grub/grub2.inc
+++ b/meta/recipes-bsp/grub/grub2.inc
@@ -74,6 +74,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
            file://0025-affs-Fix-memory-leaks.patch \
            file://0026-libgcrypt-mpi-Fix-possible-unintended-sign-extension.patch \
            file://0027-libgcrypt-mpi-Fix-possible-NULL-dereference.patch \
+           file://0028-syslinux-Fix-memory-leak-while-parsing.patch \
            "
 SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
 SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"