Thanks for the review! that can't be null and I found another mistake. I will fix this issue and send a v2 patch soon.
Michael Niedermayer <mich...@niedermayer.cc> 于2025年4月16日周三 07:33写道: > Hi > > On Fri, Apr 11, 2025 at 03:48:08PM +0800, xiaohuan...@gmail.com wrote: > > From: xiaohuanshu <xiaohuan...@gmail.com> > > > > Problem: > > The max_url_size calculation for DASH segment URLs only considered the > base URL > > length, leading to buffer overflow when the segment's sourceURL exceeded > the > > pre-allocated buffer. This triggered the log error: > > "DASH request for url 'invalid:truncated'". > > > > Reproduce: > > 1. A test sample "long-sourceurl-sample.mpd" (deliberately designed with > a long > > sourceURL) was uploaded to VideoLAN's repository. > > 2. Reproduce with short base path: > > ffmpeg -i /tmp/short_path/long-sourceurl-sample.mpd > > -> Triggers "invalid:truncated" error > > 3. With artificially lengthened base path (e.g. /aaa/../bbb/../...): > > ffmpeg -i > /long/../path/../with/../many/../segments/long-sourceurl-sample.mpd > > -> URL resolves correctly (though HTTP fetch fails due to fake URL) > > > > Fix: > > Recalculate max_url_size by considering both base URL and sourceURL > lengths, > > ensuring sufficient buffer allocation during URL concatenation. > > > > Signed-off-by: xiaohuanshu <xiaohuan...@gmail.com> > > --- > > libavformat/dashdec.c | 14 +++++++++++++- > > 1 file changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c > > index c3f3d7f3f8..f604d363c4 100644 > > --- a/libavformat/dashdec.c > > +++ b/libavformat/dashdec.c > > @@ -606,7 +606,7 @@ static int > parse_manifest_segmenturlnode(AVFormatContext *s, struct representati > > char *initialization_val = NULL; > > char *media_val = NULL; > > char *range_val = NULL; > > - int max_url_size = c ? c->max_url_size: MAX_URL_SIZE; > > + int max_url_size = 0; > > int err; > > > > if (!av_strcasecmp(fragmenturl_node->name, "Initialization")) { > > @@ -620,6 +620,12 @@ static int > parse_manifest_segmenturlnode(AVFormatContext *s, struct representati > > xmlFree(initialization_val); > > return AVERROR(ENOMEM); > > } > > + max_url_size = FFMAX( > > > + c ? c->max_url_size : 0, > > how can c be NULL here ? > > > > + initialization_val ? aligned(strlen(initialization_val) > + > > + (rep_id_val ? > strlen(rep_id_val) : 0) + > > + (rep_bandwidth_val ? > strlen(rep_bandwidth_val) : 0)) : 0); > > + max_url_size = max_url_size ? max_url_size : MAX_URL_SIZE; > > rep->init_section->url = get_content_url(baseurl_nodes, 4, > > max_url_size, > > rep_id_val, > > @@ -641,6 +647,12 @@ static int > parse_manifest_segmenturlnode(AVFormatContext *s, struct representati > > xmlFree(media_val); > > return AVERROR(ENOMEM); > > } > > + max_url_size = FFMAX( > > + c ? c->max_url_size : 0, > > > + initialization_val ? aligned(strlen(initialization_val) > + > > how can initialization_val be non NULL here ? > > thx > > [...] > > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > I have often repented speaking, but never of holding my tongue. > -- Xenocrates > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".