[dunfell][PATCH] grub2: fix CVE-2021-20233 Heap out-of-bounds write error

[dunfell][PATCH] grub2: fix CVE-2021-20233 Heap out-of-bounds write error

[Hitendra Prajapati]

Upstream-Status: Backport [https://launchpad.net/debian/+source/grub2/2.02+dfsg1-20+deb10u4/]

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
---
 .../grub/files/CVE-2021-20233.patch           | 50 +++++++++++++++++++
 meta/recipes-bsp/grub/grub2.inc               |  1 +
 2 files changed, 51 insertions(+)
 create mode 100644 meta/recipes-bsp/grub/files/CVE-2021-20233.patch

diff --git a/meta/recipes-bsp/grub/files/CVE-2021-20233.patch b/meta/recipes-bsp/grub/files/CVE-2021-20233.patch
new file mode 100644
index 0000000000..f001be4bf1
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/CVE-2021-20233.patch
@@ -0,0 +1,50 @@
+From c38a6f3b02357f5a8626acb08a92b29aee95d25c Mon Sep 17 00:00:00 2001
+From: Daniel Axtens <dja@axtens.net>
+Date: Fri, 22 Jan 2021 17:10:48 +1100
+Subject: commands/menuentry: Fix quoting in setparams_prefix()
+
+Commit 9acdcbf32542 (use single quotes in menuentry setparams command)
+says that expressing a quoted single quote will require 3 characters. It
+actually requires (and always did require!) 4 characters:
+
+  str: a'b => a'\''b
+  len:  3  => 6 (2 for the letters + 4 for the quote)
+
+This leads to not allocating enough memory and thus out of bounds writes
+that have been observed to cause heap corruption.
+
+Allocate 4 bytes for each single quote.
+
+Commit 22e7dbb2bb81 (Fix quoting in legacy parser.) does the same
+quoting, but it adds 3 as extra overhead on top of the single byte that
+the quote already needs. So it's correct.
+
+Fixes: CVE-2021-20233
+Fixes: 9acdcbf32542 (use single quotes in menuentry setparams command)
+
+Signed-off-by: Daniel Axtens <dja@axtens.net>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport [https://launchpad.net/debian/+source/grub2/2.02+dfsg1-20+deb10u4/]
+CVE: CVE-2021-20233
+Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
+---
+ grub-core/commands/menuentry.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/grub-core/commands/menuentry.c b/grub-core/commands/menuentry.c
+index 9164df7..720e6d8 100644
+--- a/grub-core/commands/menuentry.c
++++ b/grub-core/commands/menuentry.c
+@@ -230,7 +230,7 @@ setparams_prefix (int argc, char **args)
+       len += 3; /* 3 = 1 space + 2 quotes */
+       p = args[i];
+       while (*p)
+-	len += (*p++ == '\'' ? 3 : 1);
++	len += (*p++ == '\'' ? 4 : 1);
+     }
+ 
+   result = grub_malloc (len + 2);
+-- 
+2.25.1
+
diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc
index 9da18a2adc..5a6e213936 100644
--- a/meta/recipes-bsp/grub/grub2.inc
+++ b/meta/recipes-bsp/grub/grub2.inc
@@ -108,6 +108,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
            file://CVE-2022-3775.patch \
            file://CVE-2020-27749.patch \
            file://CVE-2021-20225.patch \
+           file://CVE-2021-20233.patch \
            "
 SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
 SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"
-- 
2.25.1