Fix CVE-2021-3981

(cherry picked from commit d6a3fb11e7110c0ba1263ba7690679e23383a9bf)

backport-CVE-2021-3981-restore-umask-for-the-grub.patch

@@ -0,0 +1,41 @@
+From 0adec29674561034771c13e446069b41ef41e4d4 Mon Sep 17 00:00:00 2001
+From: Michael Chang <mchang@suse.com>
+Date: Fri, 3 Dec 2021 16:13:28 +0800
+Subject: grub-mkconfig: Restore umask for the grub.cfg
+
+The commit ab2e53c8a (grub-mkconfig: Honor a symlink when generating
+configuration by grub-mkconfig) has inadvertently discarded umask for
+creating grub.cfg in the process of running grub-mkconfig. The resulting
+wrong permission (0644) would allow unprivileged users to read GRUB
+configuration file content. This presents a low confidentiality risk
+as grub.cfg may contain non-secured plain-text passwords.
+
+This patch restores the missing umask and sets the creation file mode
+to 0600 preventing unprivileged access.
+
+Fixes: CVE-2021-3981
+
+Signed-off-by: Michael Chang <mchang@suse.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ util/grub-mkconfig.in | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in
+index c3ea761..62335d0 100644
+--- a/util/grub-mkconfig.in
++++ b/util/grub-mkconfig.in
+@@ -301,7 +301,10 @@ and /etc/grub.d/* files or please file a bug report with
+     exit 1
+   else
+     # none of the children aborted with error, install the new grub.cfg
++    oldumask=$(umask)
++    umask 077
+     cat ${grub_cfg}.new > ${grub_cfg}
++    umask $oldumask
+     rm -f ${grub_cfg}.new
+   fi
+ fi
+-- 
+cgit v1.1
+

grub.patches

@@ -353,3 +353,4 @@ Patch0352: backport-0079-efi-tpm-Fix-typo-in-grub_efi_tpm2_protocol-struct.patch
 Patch0353: backport-0080-misc-Add-parentheses-around-ALIGN_UP-and-ALIGN_DOWN-.patch
 Patch0354: backport-0081-verifiers-Fix-calling-uninitialized-function-pointer.patch
 Patch0355: backport-templates-Fix-bad-test-on-GRUB_DISABLE_SUBMENU.patch
+Patch0356: backport-CVE-2021-3981-restore-umask-for-the-grub.patch

grub2.spec

@@ -8,7 +8,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.04
-Release:	22
+Release:	23
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPLv3+
 URL:		http://www.gnu.org/software/grub/
@@ -450,6 +450,12 @@ rm -r /boot/grub2.tmp/ || :
 %{_datadir}/man/man*
 
 %changelog
+* Wed Mar 16 2022 xihaochen <xihaochen@h-partners.com> - 2.04-23
+- Type:CVE
+- CVE:CVE-2021-3981
+- SUG:NA
+- DESC:Fix CVE-2021-3981
+
 * Sat Feb 26 2022 zhangqiumiao <zhangqiumiao1@huawei.com> - 2.04-22
 - Type:bugfix
 - CVE:NA