Signed-off-by: Yongxin Liu <[email protected]> --- ...onfig-Restore-umask-for-the-grub.cfg.patch | 49 +++++++++++++++++++ meta/recipes-bsp/grub/grub2.inc | 1 + 2 files changed, 50 insertions(+) create mode 100644 meta/recipes-bsp/grub/files/CVE-2021-3981-grub-mkconfig-Restore-umask-for-the-grub.cfg.patch
diff --git a/meta/recipes-bsp/grub/files/CVE-2021-3981-grub-mkconfig-Restore-umask-for-the-grub.cfg.patch b/meta/recipes-bsp/grub/files/CVE-2021-3981-grub-mkconfig-Restore-umask-for-the-grub.cfg.patch new file mode 100644 index 0000000000..dae26fd8bb --- /dev/null +++ b/meta/recipes-bsp/grub/files/CVE-2021-3981-grub-mkconfig-Restore-umask-for-the-grub.cfg.patch @@ -0,0 +1,49 @@ +From 0adec29674561034771c13e446069b41ef41e4d4 Mon Sep 17 00:00:00 2001 +From: Michael Chang <[email protected]> +Date: Fri, 3 Dec 2021 16:13:28 +0800 +Subject: [PATCH] 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 <[email protected]> +Reviewed-by: Daniel Kiper <[email protected]> + +Upstream-Status: Backport +CVE: CVE-2021-3981 + +Reference to upstream patch: +https://git.savannah.gnu.org/cgit/grub.git/commit/?id=0adec29674561034771c13e446069b41ef41e4d4 + +Signed-off-by: Yongxin Liu <[email protected]> +--- + util/grub-mkconfig.in | 3 +++ + 1 file changed, 3 insertions(+) + +diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in +index c3ea7612e..62335d027 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 ${grub_cfg}.new + fi + fi +-- +2.31.1 + diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc index bb791347dc..a72a562c5a 100644 --- a/meta/recipes-bsp/grub/grub2.inc +++ b/meta/recipes-bsp/grub/grub2.inc @@ -20,6 +20,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \ file://0001-grub.d-10_linux.in-add-oe-s-kernel-name.patch \ file://determinism.patch \ file://0001-RISC-V-Restore-the-typcast-to-long.patch \ + file://CVE-2021-3981-grub-mkconfig-Restore-umask-for-the-grub.cfg.patch \ " SRC_URI[sha256sum] = "23b64b4c741569f9426ed2e3d0e6780796fca081bee4c99f62aa3f53ae803f5f" -- 2.31.1
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