mjpegdec: extend check for incompatible values of s->rgb and s->ls
authorAndreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Thu, 31 Dec 2015 15:55:43 +0000 (16:55 +0100)
committerMichael Niedermayer <michael@niedermayer.cc>
Fri, 15 Jan 2016 16:23:54 +0000 (17:23 +0100)
This can happen if s->ls changes from 0 to 1, but picture allocation is
skipped due to s->interlaced.

In that case ff_jpegls_decode_picture could be called even though the
s->picture_ptr frame has the wrong pixel format and thus a wrong
linesize, which results in a too small zero buffer being allocated.

This fixes an out-of-bounds read in ls_decode_line.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
(cherry picked from commit 7ea2db6eafa0a8a9497aab20be2cfc8742a59072)

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/mjpegdec.c

index 8a190fc..57279bf 100644 (file)
@@ -606,7 +606,8 @@ unk_pixfmt:
         av_log(s->avctx, AV_LOG_DEBUG, "decode_sof0: error, len(%d) mismatch\n", len);
     }
 
-    if (s->rgb && !s->lossless && !s->ls) {
+    if ((s->rgb && !s->lossless && !s->ls) ||
+        (!s->rgb && s->ls && s->nb_components > 1)) {
         av_log(s->avctx, AV_LOG_ERROR, "Unsupported coding and pixel format combination\n");
         return AVERROR_PATCHWELCOME;
     }