From: Lidong Chen <lidong.chen@oracle.com>
Date: Wed, 29 Jan 2025 06:48:37 +0000 (+0000)
Subject: script/execute: Fix potential underflow and NULL dereference
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d13b6e8ebd10b4eb16698a002aa40258cf6e6f0e;p=thirdparty%2Fgrub.git

script/execute: Fix potential underflow and NULL dereference

The result is initialized to 0 in grub_script_arglist_to_argv().
If the for loop condition is not met both result.args and result.argc
remain 0 causing result.argc - 1 to underflow and/or result.args NULL
dereference. Fix the issues by adding relevant checks.

Fixes: CID 473880

Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---

diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c
index e1450f45d..a86e0051f 100644
--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@@ -760,6 +760,9 @@ cleanup:
 	}
     }
 
+  if (result.args == NULL || result.argc == 0)
+    goto fail;
+
   if (! result.args[result.argc - 1])
     result.argc--;