grub2/0371-script-execute-Don-t-let-trailing-blank-lines-determ.patch
Leo Sandoval 2ba9cee552 Fix the fallback mechanism when menu entries fail to boot
Resolves: RHEL-113024
Signed-off-by: Leo Sandoval <lsandova@redhat.com>
2025-09-08 14:10:24 -06:00

67 lines
2.2 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: James Le Cuirot <jlecuirot@microsoft.com>
Date: Thu, 24 Oct 2024 14:42:46 +0100
Subject: [PATCH] script/execute: Don't let trailing blank lines determine the
return code
grub_script_execute_sourcecode() parses and executes code one line at a
time, updating the return code each time because only the last line
determines the final status. However, trailing new lines were also
executed, masking any failure on the previous line. Fix this by only
trying to execute the command when there is actually one present.
This has presumably never been noticed because this code is not used by
regular functions, only in special cases like eval and menu entries. The
latter generally don't return at all, having booted an OS. When failing
to boot, upstream GRUB triggers the fallback mechanism regardless of the
return code.
We noticed the problem while using Red Hat's patches, which change this
behaviour to take account of the return code. In that case, a failure
takes you back to the menu rather than triggering a fallback.
Signed-off-by: James Le Cuirot <jlecuirot@microsoft.com>
---
grub-core/script/execute.c | 5 ++++-
tests/grub_script_eval.in | 10 +++++++++-
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c
index 014132703..3d26a3fe4 100644
--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@@ -952,7 +952,10 @@ grub_script_execute_sourcecode (const char *source)
break;
}
- ret = grub_script_execute (parsed_script);
+ /* Don't let trailing blank lines determine the return code. */
+ if (parsed_script->cmd)
+ ret = grub_script_execute (parsed_script);
+
grub_script_free (parsed_script);
grub_free (line);
}
diff --git a/tests/grub_script_eval.in b/tests/grub_script_eval.in
index c97b78d77..9c6211042 100644
--- a/tests/grub_script_eval.in
+++ b/tests/grub_script_eval.in
@@ -3,4 +3,12 @@
eval echo "Hello world"
valname=tst
eval $valname=hi
-echo $tst
\ No newline at end of file
+echo $tst
+
+if eval "
+false
+"; then
+ echo should have failed
+else
+ echo failed as expected
+fi
--
2.48.1