From 2c34af908ebf4856051ed29e46d88abd2b20387f Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Fri, 8 Mar 2024 22:47:20 +1100
Subject: [PATCH 32/73] video/readers/jpeg: Do not permit duplicate SOF0
 markers in JPEG

Otherwise a subsequent header could change the height and width
allowing future OOB writes.

Fixes: CVE-2024-45774

Reported-by: Nils Langius <nils@langius.de>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/video/readers/jpeg.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c
index ae634fd41..631a89356 100644
--- a/grub-core/video/readers/jpeg.c
+++ b/grub-core/video/readers/jpeg.c
@@ -339,6 +339,10 @@ grub_jpeg_decode_sof (struct grub_jpeg_data *data)
   if (grub_errno != GRUB_ERR_NONE)
     return grub_errno;
 
+  if (data->image_height != 0 || data->image_width != 0)
+    return grub_error (GRUB_ERR_BAD_FILE_TYPE,
+		       "jpeg: cannot have duplicate SOF0 markers");
+
   if (grub_jpeg_get_byte (data) != 8)
     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 		       "jpeg: only 8-bit precision is supported");
-- 
2.33.0

