1From 5f5eb7ca8e971227e95745abe541df3e1509360e Mon Sep 17 00:00:00 2001
2From: Darren Kenny <darren.kenny@oracle.com>
3Date: Fri, 4 Dec 2020 15:39:00 +0000
4Subject: [PATCH] video/readers/jpeg: Test for an invalid next marker reference
5 from a jpeg file
6
7While it may never happen, and potentially could be caught at the end of
8the function, it is worth checking up front for a bad reference to the
9next marker just in case of a maliciously crafted file being provided.
10
11Fixes: CID 73694
12
13Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
14Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
15Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
16---
17 grub-core/video/readers/jpeg.c | 6 ++++++
18 1 file changed, 6 insertions(+)
19
20diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c
21index 31359a4..0b6ce3c 100644
22--- a/grub-core/video/readers/jpeg.c
23+++ b/grub-core/video/readers/jpeg.c
24@@ -253,6 +253,12 @@ grub_jpeg_decode_quan_table (struct grub_jpeg_data *data)
25   next_marker = data->file->offset;
26   next_marker += grub_jpeg_get_word (data);
27
28+  if (next_marker > data->file->size)
29+    {
30+      /* Should never be set beyond the size of the file. */
31+      return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid next reference");
32+    }
33+
34   while (data->file->offset + sizeof (data->quan_table[id]) + 1
35 	 <= next_marker)
36     {
37--
382.14.2
39
40