grub2/SOURCES/0419-video-readers-jpeg-Test-for-an-invalid-next-marker-r.patch
2022-05-10 10:22:45 +00:00

36 lines
1.3 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Darren Kenny <darren.kenny@oracle.com>
Date: Fri, 4 Dec 2020 15:39:00 +0000
Subject: [PATCH] video/readers/jpeg: Test for an invalid next marker reference
from a jpeg file
While it may never happen, and potentially could be caught at the end of
the function, it is worth checking up front for a bad reference to the
next marker just in case of a maliciously crafted file being provided.
Fixes: CID 73694
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
grub-core/video/readers/jpeg.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c
index 31359a4c9..0b6ce3cee 100644
--- a/grub-core/video/readers/jpeg.c
+++ b/grub-core/video/readers/jpeg.c
@@ -253,6 +253,12 @@ grub_jpeg_decode_quan_table (struct grub_jpeg_data *data)
next_marker = data->file->offset;
next_marker += grub_jpeg_get_word (data);
+ if (next_marker > data->file->size)
+ {
+ /* Should never be set beyond the size of the file. */
+ return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid next reference");
+ }
+
while (data->file->offset + sizeof (data->quan_table[id]) + 1
<= next_marker)
{