avcodec/mjpegdec: Check number of components for JPEG-LS

Fixes out of array accesses
Fixes: asan_heap-oob_1c1a4ea_1242_cov_2274415971_TESTcmyk.jpg

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit fabbfaa095660982cc0bc63242c459561fa37037)

Conflicts:

	libavcodec/mjpegdec.c

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 8a6d50d..a0dcbc7 100644 (file)
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -347,9 +347,12 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
         return -1;
     }
     if(s->ls){
-        if(s->nb_components > 1)
+        if(s->nb_components == 3) {
             s->avctx->pix_fmt = PIX_FMT_RGB24;
-        else if(s->bits <= 8)
+        } else if (s->nb_components != 1) {
+            av_log(s->avctx, AV_LOG_ERROR, "Unsupported number of components %d\n", s->nb_components);
+            return AVERROR_PATCHWELCOME;
+        } else if (s->bits <= 8)
             s->avctx->pix_fmt = PIX_FMT_GRAY8;
         else
             s->avctx->pix_fmt = PIX_FMT_GRAY16;