From bb23bf8fd7fb4771b0f08a4ee1ba8fe6ca16d14f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 10 Sep 2013 13:39:57 +0200 Subject: [PATCH] avfilter/avfilter: fix null pointer dereference with queued ping filters Signed-off-by: Michael Niedermayer --- libavfilter/avfilter.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c index 7f69f86ea4..765b37a389 100644 --- a/libavfilter/avfilter.c +++ b/libavfilter/avfilter.c @@ -427,7 +427,15 @@ void ff_update_link_current_pts(AVFilterLink *link, int64_t pts) int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags) { if(!strcmp(cmd, "ping")){ + char local_res[256] = {0}; + + if (!res) { + res = local_res; + res_len = sizeof(local_res); + } av_strlcatf(res, res_len, "pong from:%s %s\n", filter->filter->name, filter->name); + if (res == local_res) + av_log(filter, AV_LOG_INFO, "%s", res); return 0; }else if(!strcmp(cmd, "enable")) { return set_enable_expr(filter, arg);