1From 0adec29674561034771c13e446069b41ef41e4d4 Mon Sep 17 00:00:00 2001 2From: Michael Chang <mchang@suse.com> 3Date: Fri, 3 Dec 2021 16:13:28 +0800 4Subject: [PATCH] grub-mkconfig: Restore umask for the grub.cfg 5 6The commit ab2e53c8a (grub-mkconfig: Honor a symlink when generating 7configuration by grub-mkconfig) has inadvertently discarded umask for 8creating grub.cfg in the process of running grub-mkconfig. The resulting 9wrong permission (0644) would allow unprivileged users to read GRUB 10configuration file content. This presents a low confidentiality risk 11as grub.cfg may contain non-secured plain-text passwords. 12 13This patch restores the missing umask and sets the creation file mode 14to 0600 preventing unprivileged access. 15 16Fixes: CVE-2021-3981 17 18Signed-off-by: Michael Chang <mchang@suse.com> 19Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> 20 21Upstream-Status: Backport 22CVE: CVE-2021-3981 23 24Reference to upstream patch: 25https://git.savannah.gnu.org/cgit/grub.git/commit/?id=0adec29674561034771c13e446069b41ef41e4d4 26 27Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com> 28--- 29 util/grub-mkconfig.in | 3 +++ 30 1 file changed, 3 insertions(+) 31 32diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in 33index c3ea7612e..62335d027 100644 34--- a/util/grub-mkconfig.in 35+++ b/util/grub-mkconfig.in 36@@ -301,7 +301,10 @@ and /etc/grub.d/* files or please file a bug report with 37 exit 1 38 else 39 # none of the children aborted with error, install the new grub.cfg 40+ oldumask=$(umask) 41+ umask 077 42 cat ${grub_cfg}.new > ${grub_cfg} 43+ umask $oldumask 44 rm -f ${grub_cfg}.new 45 fi 46 fi 47-- 482.31.1 49 50