[FFmpeg-devel] [PATCH] proresdec_lgpl: explicitly check coff[3] against slice_data_size

Andreas Cadhalpun andreas.cadhalpun at googlemail.com
Thu Nov 10 00:56:36 EET 2016


The implicit checks via v_data_size and a_data_size don't work in the case
'(hdr_size > 7) && !ctx->alpha_info'.

This fixes segmentation faults due to invalid reads.

This problem was introduced in commit
547c2f002a87f4412a83c23b0d60364be5e7ce58.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
---
 libavcodec/proresdec_lgpl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/proresdec_lgpl.c b/libavcodec/proresdec_lgpl.c
index 467a423..bc5bdb5 100644
--- a/libavcodec/proresdec_lgpl.c
+++ b/libavcodec/proresdec_lgpl.c
@@ -625,7 +625,7 @@ static int decode_slice(AVCodecContext *avctx, void *tdata)
 
     /* if V or alpha component size is negative that means that previous
        component sizes are too large */
-    if (v_data_size < 0 || a_data_size < 0 || hdr_size < 6) {
+    if (v_data_size < 0 || a_data_size < 0 || hdr_size < 6 || coff[3] > slice_data_size) {
         av_log(avctx, AV_LOG_ERROR, "invalid data size\n");
         return AVERROR_INVALIDDATA;
     }
-- 
2.10.2



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