From c1b966a189f3ffef8bd48d744e644f573a218608 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Fri, 12 Aug 2022 00:27:41 +0200 Subject: [PATCH] avcodec/mimic: Fix undefined pointer arithmetic NULL + anything is UB. Reviewed-by: Michael Niedermayer Signed-off-by: Andreas Rheinhardt --- libavcodec/mimic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/libavcodec/mimic.c b/libavcodec/mimic.c index ce5c2afd19..bcf10b7ae1 100644 --- a/libavcodec/mimic.c +++ b/libavcodec/mimic.c @@ -268,8 +268,9 @@ static int decode(MimicContext *ctx, int quality, int num_coeffs, const int qscale = av_clip(10000 - quality, is_chroma ? 1000 : 2000, 10000) << 2; const int stride = ctx->frames[ctx->cur_index ].f->linesize[plane]; - const uint8_t *src = ctx->frames[ctx->prev_index].f->data[plane]; uint8_t *dst = ctx->frames[ctx->cur_index ].f->data[plane]; + /* src is unused for I frames; set to avoid UB pointer arithmetic. */ + const uint8_t *src = is_iframe ? dst : ctx->frames[ctx->prev_index].f->data[plane]; for (y = 0; y < ctx->num_vblocks[plane]; y++) { for (x = 0; x < ctx->num_hblocks[plane]; x++) {