[FFmpeg-cvslog] avfilter/vf_paletteuse: Fix leaks of AVFilterFormats on error

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Fri Aug  7 06:09:59 2020 +0200| [6a65449954d466e76c1166f524d2f6cde28c3c96] | committer: Andreas Rheinhardt

avfilter/vf_paletteuse: Fix leaks of AVFilterFormats on error

The paletteuse's query_formats function allocated three AVFilterFormats
before storing them permanently. If allocating one of them failed, the
three AVFilterFormats structures would be freed with av_freep() which
does not free separately allocated subelements (namely the formats
array) which leak.

Furthermore, if storing one of the first two fails, the function simply
returns and the ones not yet stored leak.

These leaks have been fixed by only creating a new AVFilterFormats after
the last one has already been permanently stored. Furthermore, it is
enough to check whether the elements have been properly stored as
ff_formats_ref() by design returns AVERROR(ENOMEM) if it is provided a
NULL AVFilterFormats *.

Fixes Coverity issues #1270818 and #1270819.

Reviewed-by: Nicolas George <george at nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6a65449954d466e76c1166f524d2f6cde28c3c96
---

 libavfilter/vf_paletteuse.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/libavfilter/vf_paletteuse.c b/libavfilter/vf_paletteuse.c
index b32ff817d0..80e2ba583a 100644
--- a/libavfilter/vf_paletteuse.c
+++ b/libavfilter/vf_paletteuse.c
@@ -142,18 +142,12 @@ static int query_formats(AVFilterContext *ctx)
     static const enum AVPixelFormat inpal_fmts[] = {AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE};
     static const enum AVPixelFormat out_fmts[]   = {AV_PIX_FMT_PAL8,  AV_PIX_FMT_NONE};
     int ret;
-    AVFilterFormats *in    = ff_make_format_list(in_fmts);
-    AVFilterFormats *inpal = ff_make_format_list(inpal_fmts);
-    AVFilterFormats *out   = ff_make_format_list(out_fmts);
-    if (!in || !inpal || !out) {
-        av_freep(&in);
-        av_freep(&inpal);
-        av_freep(&out);
-        return AVERROR(ENOMEM);
-    }
-    if ((ret = ff_formats_ref(in   , &ctx->inputs[0]->out_formats)) < 0 ||
-        (ret = ff_formats_ref(inpal, &ctx->inputs[1]->out_formats)) < 0 ||
-        (ret = ff_formats_ref(out  , &ctx->outputs[0]->in_formats)) < 0)
+    if ((ret = ff_formats_ref(ff_make_format_list(in_fmts),
+                              &ctx->inputs[0]->out_formats)) < 0 ||
+        (ret = ff_formats_ref(ff_make_format_list(inpal_fmts),
+                              &ctx->inputs[1]->out_formats)) < 0 ||
+        (ret = ff_formats_ref(ff_make_format_list(out_fmts),
+                              &ctx->outputs[0]->in_formats)) < 0)
         return ret;
     return 0;
 }