grub: fix a memory leak

Add a fix of a memory leak in grub's commands/hashsum. 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: de075f9421a16e1728968349ba16b0d68d47efea)

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, 57 insertions, 0 deletions

diff --git a/meta/recipes-bsp/grub/files/0030-commands-hashsum-Fix-a-memory-leak.patch b/meta/recipes-bsp/grub/files/0030-commands-hashsum-Fix-a-memory-leak.patch
new file mode 100644
index 0000000000..e34a19e12c
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/0030-commands-hashsum-Fix-a-memory-leak.patch
@@ -0,0 +1,56 @@
+From b136fa14d26d1833ffcb852f86e65da5960cfb99 Mon Sep 17 00:00:00 2001
+From: Chris Coulson <chris.coulson@canonical.com>
+Date: Tue, 1 Dec 2020 23:41:24 +0000
+Subject: [PATCH] commands/hashsum: Fix a memory leak
+
+check_list() uses grub_file_getline(), which allocates a buffer.
+If the hash list file contains invalid lines, the function leaks
+this buffer when it returns an error.
+
+Fixes: CID 176635
+
+Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=8b6f528e52e18b7a69f90b8dc3671d7b1147d9f3]
+Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
+---
+ grub-core/commands/hashsum.c | 15 ++++++++++++---
+ 1 file changed, 12 insertions(+), 3 deletions(-)
+
+diff --git a/grub-core/commands/hashsum.c b/grub-core/commands/hashsum.c
+index 456ba90..b8a22b0 100644
+--- a/grub-core/commands/hashsum.c
++++ b/grub-core/commands/hashsum.c
+@@ -128,11 +128,17 @@ check_list (const gcry_md_spec_t *hash, const char *hashfilename,
+          high = hextoval (*p++);
+          low = hextoval (*p++);
+          if (high < 0 || low < 0)
+-           return grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid hash list");
++           {
++             grub_free (buf);
++             return grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid hash list");
++           }
+          expected[i] = (high << 4) | low;
+        }
+       if ((p[0] != ' ' && p[0] != '\t') || (p[1] != ' ' && p[1] != '\t'))
+-       return grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid hash list");
++       {
++         grub_free (buf);
++         return grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid hash list");
++       }
+       p += 2;
+       if (prefix)
+        {
+@@ -140,7 +146,10 @@ check_list (const gcry_md_spec_t *hash, const char *hashfilename,
+          
+          filename = grub_xasprintf ("%s/%s", prefix, p);
+          if (!filename)
+-           return grub_errno;
++           {
++             grub_free (buf);
++             return grub_errno;
++           }
+          file = grub_file_open (filename, GRUB_FILE_TYPE_TO_HASH
+                                 | (!uncompress ? GRUB_FILE_TYPE_NO_DECOMPRESS
+                                    : GRUB_FILE_TYPE_NONE));
diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc
index 1460e559b9..d18e329b96 100644
--- a/meta/recipes-bsp/grub/grub2.inc
+++ b/meta/recipes-bsp/grub/grub2.inc
@@ -76,6 +76,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
            file://0027-libgcrypt-mpi-Fix-possible-NULL-dereference.patch \
            file://0028-syslinux-Fix-memory-leak-while-parsing.patch \
            file://0029-normal-completion-Fix-leaking-of-memory-when-process.patch \
+           file://0030-commands-hashsum-Fix-a-memory-leak.patch \
            "
 SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
 SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"