From 166a4d61448f74745afe1dac2f2cfb85d04909bf Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Mon, 28 Jun 2021 14:25:17 +1000
Subject: 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.

Reference:https://git.savannah.gnu.org/cgit/grub.git/commit/?id=166a4d61448f74745afe1dac2f2cfb85d04909bf
Conflict:NA

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 2284a6c..579bbe8 100644
--- a/grub-core/video/readers/jpeg.c
+++ b/grub-core/video/readers/jpeg.c
@@ -683,6 +683,9 @@ 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))
@@ -705,8 +708,8 @@ 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)
-- 
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