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>
This commit is contained in:
Daniel Axtens 2021-06-28 14:25:17 +10:00 committed by Daniel Kiper
parent 768ef2199e
commit 166a4d6144

View File

@ -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)