[FFmpeg-devel] [PATCH] avcodec/cscd: Check for CamStudio Lossless Codec 1.0 behavior in end check

Michael Niedermayer michael at niedermayer.cc
Thu Mar 9 00:43:38 EET 2023


Alternatively the check could be simply made more tolerant
Fixes: Ticket10227

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/cscd.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/cscd.c b/libavcodec/cscd.c
index b4ed3332a9..5d55f6e4d1 100644
--- a/libavcodec/cscd.c
+++ b/libavcodec/cscd.c
@@ -83,7 +83,10 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
     switch ((buf[0] >> 1) & 7) {
     case 0: { // lzo compression
         int outlen = c->decomp_size, inlen = buf_size - 2;
-        if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen) || outlen) {
+        int bpp = avctx->bits_per_coded_sample / 8;
+        int bugdelta = FFALIGN(avctx->width * bpp, 4)       * avctx->height
+                     -        (avctx->width     & ~3) * bpp * avctx->height;
+        if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen) || (outlen && outlen != bugdelta)) {
             av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
             return AVERROR_INVALIDDATA;
         }
-- 
2.17.1



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