[FFmpeg-devel] [PATCH 01/10] avcodec/cbs_h2645: Fix potential out-of-bounds array access

Andreas Rheinhardt andreas.rheinhardt at gmail.com
Wed Sep 18 06:25:58 EEST 2019


The maximum allowed index for an array access is FF_ARRAY_ELEMS - 1; yet
the current code allowed FF_ARRAY_ELEMS. This wasn't dangerous in practice,
as parameter sets with invalid ids were already filtered out during
reading.

Found via PVS-Studio (see ticket #8156).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
 libavcodec/cbs_h2645.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index 8da8421e47..69e71a7526 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -748,7 +748,7 @@ static int cbs_h26 ## h26n ## _replace_ ## ps_var(CodedBitstreamContext *ctx, \
     CodedBitstreamH26 ## h26n ## Context *priv = ctx->priv_data; \
     H26 ## h26n ## Raw ## ps_name *ps_var = unit->content; \
     unsigned int id = ps_var->id_element; \
-    if (id > FF_ARRAY_ELEMS(priv->ps_var)) { \
+    if (id >= FF_ARRAY_ELEMS(priv->ps_var)) { \
         av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid " #ps_name \
                " id : %d.\n", id); \
         return AVERROR_INVALIDDATA; \
-- 
2.20.1



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