grub: avoid a NULL pointer dereference

This patch adds a fix for a NULL pointer dereference in grub's
commands/ls. 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: 6666dccd33178445f3c4fe277354393efb70285a)

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/0045-commands-ls-Require-device_name-is-not-NULL-before-p.patch

@@ -0,0 +1,33 @@
+From dd82f98fa642907817f59aeaf3761b786898df85 Mon Sep 17 00:00:00 2001
+From: Daniel Axtens <dja@axtens.net>
+Date: Mon, 11 Jan 2021 16:57:37 +1100
+Subject: [PATCH] commands/ls: Require device_name is not NULL before printing
+
+This can be triggered with:
+  ls -l (0 0*)
+and causes a NULL deref in grub_normal_print_device_info().
+
+I'm not sure if there's any implication with the IEEE 1275 platform.
+
+Signed-off-by: Daniel Axtens <dja@axtens.net>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=6afbe6063c95b827372f9ec310c9fc7461311eb1]
+Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
+---
+ grub-core/commands/ls.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/grub-core/commands/ls.c b/grub-core/commands/ls.c
+index 5b7491a..326d2d6 100644
+--- a/grub-core/commands/ls.c
++++ b/grub-core/commands/ls.c
+@@ -196,7 +196,7 @@ grub_ls_list_files (char *dirname, int longlist, int all, int human)
+       goto fail;
+     }
+ 
+-  if (! *path)
++  if (! *path && device_name)
+     {
+       if (grub_errno == GRUB_ERR_UNKNOWN_FS)
+ 	grub_errno = GRUB_ERR_NONE;

meta/recipes-bsp/grub/grub2.inc

@@ -91,6 +91,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
            file://0042-util-grub-editenv-Fix-incorrect-casting-of-a-signed-.patch \
            file://0043-util-glue-efi-Fix-incorrect-use-of-a-possibly-negati.patch \
            file://0044-script-execute-Fix-NULL-dereference-in-grub_script_e.patch \
+           file://0045-commands-ls-Require-device_name-is-not-NULL-before-p.patch \
            "
 SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
 SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"