avcodec/dxa: check dimensions

Fixes out of array access
Fixes: asan_heap-oob_11222fb_21_020.dxa
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <[email protected]>
(cherry picked from commit e70312dfc22c4e54d5716f28f28db8f99c74cc90)

Conflicts:

	libavcodec/dxa.c

Signed-off-by: Michael Niedermayer <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/libavcodec/dxa.c b/libavcodec/dxa.c
index 3fda64cfef..e6caa7f0f5 100644
--- a/libavcodec/dxa.c
+++ b/libavcodec/dxa.c
@@ -304,6 +304,11 @@ static av_cold int decode_init(AVCodecContext *avctx)
 
     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 
+    if (avctx->width%4 || avctx->height%4) {
+        av_log(avctx, AV_LOG_ERROR, "dimensions are not a multiple of 4");
+        return AVERROR_INVALIDDATA;
+    }
+
     avcodec_get_frame_defaults(&c->pic);
     avcodec_get_frame_defaults(&c->prev);