File 0018-video-readers-jpeg-Refuse-to-handle-multiple-start-o.patch of Package grub2.26830

From 278071273fa335236c2236d3bf2ceb47d81221ab Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Mon, 28 Jun 2021 14:25:17 +1000
Subject: [PATCH 18/33] video/readers/jpeg: Refuse to handle multiple start of
 streams

An invalid file could contain multiple start of stream blocks, which
would cause us to reallocate and leak our bitmap. Refuse to handle
multiple start of streams.

Additionally, fix a grub_error() call formatting.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/video/readers/jpeg.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c
index 6088a377d1..b2dbc777a2 100644
--- a/grub-core/video/readers/jpeg.c
+++ b/grub-core/video/readers/jpeg.c
@@ -677,6 +677,9 @@ grub_jpeg_decode_sos (struct grub_jpeg_data *data)
   if (data->file->offset != data_offset)
     return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: extra byte in sos");
 
+  if (*data->bitmap)
+    return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: too many start of scan blocks");
+
   if (grub_video_bitmap_create (data->bitmap, data->image_width,
 				data->image_height,
 				GRUB_VIDEO_BLIT_FORMAT_RGB_888))
@@ -699,8 +702,8 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data)
   nc1 = (data->image_width + hb - 1)  >> (3 + data->log_hs);
 
   if (data->bitmap_ptr == NULL)
-    return grub_error(GRUB_ERR_BAD_FILE_TYPE,
-		      "jpeg: attempted to decode data before start of stream");
+    return grub_error (GRUB_ERR_BAD_FILE_TYPE,
+		       "jpeg: attempted to decode data before start of stream");
 
   for (; data->r1 < nr1 && (!data->dri || rst);
        data->r1++, data->bitmap_ptr += (vb * data->image_width - hb * nc1) * 3)
-- 
2.34.1