Blame SOURCES/0224-grub-mkconfig-restore-umask-for-grub.cfg.patch

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Michael Chang via Grub-devel <grub-devel@gnu.org>
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Date: Fri, 3 Dec 2021 16:13:28 +0800
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Subject: [PATCH] grub-mkconfig: restore umask for grub.cfg
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Since commit:
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  ab2e53c8a grub-mkconfig: Honor a symlink when generating configuration
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by grub-mkconfig
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has inadvertently discarded umask for creating grub.cfg in the process
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of grub-mkconfig. The resulting wrong permission (0644) would allow
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unprivileged users to read grub's configuration file content. This
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presents a low confidentiality risk as grub.cfg may contain non-secured
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plain-text passwords.
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This patch restores the missing umask and set the file mode of creation
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to 0600 preventing unprivileged access.
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Fixes: CVE-2021-3981
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Signed-off-by: Michael Chang <mchang@suse.com>
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(cherry picked from commit 2acad06610da1488bfa387f56a847119ab758766)
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---
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 util/grub-mkconfig.in | 2 ++
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 1 file changed, 2 insertions(+)
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diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in
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index f55339a3f64..520a672cd2c 100644
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--- a/util/grub-mkconfig.in
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+++ b/util/grub-mkconfig.in
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@@ -311,7 +311,9 @@ and /etc/grub.d/* files or please file a bug report with
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     exit 1
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   else
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     # none of the children aborted with error, install the new grub.cfg
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+    oldumask=$(umask); umask 077
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     cat ${grub_cfg}.new > ${grub_cfg}
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+    umask $oldumask
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     rm -f ${grub_cfg}.new
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   fi
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 fi