From 33c9e18b09f4025ae635ef24bab8eab1a686a711 Mon Sep 17 00:00:00 2001
From: Anton Khirnov <anton@khirnov.net>
Date: Sun, 17 Mar 2013 16:14:58 +0100
Subject: [PATCH] avfiltergraph: check for sws opts being non-NULL before using
them.
Avoid snprintfing a NULL pointer.
CC: libav-stable@libav.org
(cherry picked from commit 6e3c13a559e9ff300b5ca60e1d503e594d7f055c)
Signed-off-by: Reinhard Tartler <siretart@tauware.de>
---
libavfilter/avfiltergraph.c | 7 ++++++-
libavfilter/graphparser.c | 3 ++-
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index af96807531d..b7dce7576fa 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -23,6 +23,7 @@
#include <ctype.h>
#include <string.h>
+#include "libavutil/avstring.h"
#include "avfilter.h"
#include "avfiltergraph.h"
#include "internal.h"
@@ -163,7 +164,11 @@ static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
/* couldn't merge format lists. auto-insert scale filter */
snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
scaler_count++);
- snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
+ av_strlcpy(scale_args, "0:0", sizeof(scale_args));
+ if (graph->scale_sws_opts) {
+ av_strlcat(scale_args, ":", sizeof(scale_args));
+ av_strlcat(scale_args, graph->scale_sws_opts, sizeof(scale_args));
+ }
if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
inst_name, scale_args, NULL, graph)) < 0)
return ret;
diff --git a/libavfilter/graphparser.c b/libavfilter/graphparser.c
index 00fb57ad576..0678cd0b351 100644
--- a/libavfilter/graphparser.c
+++ b/libavfilter/graphparser.c
@@ -121,7 +121,8 @@ static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int ind
return ret;
}
- if (!strcmp(filt_name, "scale") && args && !strstr(args, "flags")) {
+ if (!strcmp(filt_name, "scale") && args && !strstr(args, "flags") &&
+ ctx->scale_sws_opts) {
snprintf(tmp_args, sizeof(tmp_args), "%s:%s",
args, ctx->scale_sws_opts);
args = tmp_args;
--
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