[FFmpeg-devel] [PATCH 5/9] nistspheredec: prevent overflow during block alignment calculation

[Michael Niedermayer]

On Thu, Jan 26, 2017 at 03:52:04AM +0100, Marton Balint wrote:
> 
> On Thu, 26 Jan 2017, Michael Niedermayer wrote:
> 
> >On Thu, Jan 26, 2017 at 02:58:07AM +0100, Andreas Cadhalpun wrote:
> >>On 26.01.2017 02:29, Ronald S. Bultje wrote:
> >>>On Wed, Jan 25, 2017 at 8:12 PM, Andreas Cadhalpun <
> >>>andreas.cadhalpun at googlemail.com> wrote:
> >>>
> >>>>Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
> >>>>---
> >>>> libavformat/nistspheredec.c | 11 +++++++++++
> >>>> 1 file changed, 11 insertions(+)
> >>>>
> >>>>diff --git a/libavformat/nistspheredec.c b/libavformat/nistspheredec.c
> >>>>index 782d1dfbfb..3386497682 100644
> >>>>--- a/libavformat/nistspheredec.c
> >>>>+++ b/libavformat/nistspheredec.c
> >>>>@@ -21,6 +21,7 @@
> >>>>
> >>>> #include "libavutil/avstring.h"
> >>>> #include "libavutil/intreadwrite.h"
> >>>>+#include "libavcodec/internal.h"
> >>>> #include "avformat.h"
> >>>> #include "internal.h"
> >>>> #include "pcm.h"
> >>>>@@ -90,6 +91,11 @@ static int nist_read_header(AVFormatContext *s)
> >>>>             return 0;
> >>>>         } else if (!memcmp(buffer, "channel_count", 13)) {
> >>>>             sscanf(buffer, "%*s %*s %"SCNd32, &st->codecpar->channels);
> >>>>+            if (st->codecpar->channels > FF_SANE_NB_CHANNELS) {
> >>>>+                av_log(s, AV_LOG_ERROR, "Too many channels %d > %d\n",
> >>>>+                       st->codecpar->channels, FF_SANE_NB_CHANNELS);
> >>>>+                return AVERROR(ENOSYS);
> >>>>+            }
> >>>
> >>>
> >>>I've said this before, but again - please don't add useless log messages.
> >>
> >>I disagree that these log messages are useless and I'm not the only one [1].
> >
> >+1
> >
> >Log messages make debuging the code easier, as a developer i like to
> >know why something fails having a hard failure but no clear and easy
> >findable error message is bad
> >
> 
> I tend to agree with Ronald here, log messages which are practically
> impossible to trigger with real-world files have little benefit,
> also I don't think it is ffmpeg's job to thoroughly explain every
> different kind of error.

would you want a log message be removed if the
people working on the code want the error message to be there ?
You seem to just say that you see little benefit in it.


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Into a blind darkness they enter who follow after the Ignorance,
they as if into a greater darkness enter who devote themselves
to the Knowledge alone. -- Isha Upanishad
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