[FFmpeg-cvslog] avcodec/vc2enc_dwt: Avoid NULL - 0

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Tue Feb  8 11:44:13 2022 +0100| [31da97b08325a338db7931428ba0625d4e61f168] | committer: Andreas Rheinhardt

avcodec/vc2enc_dwt: Avoid NULL - 0

It is sane, but UB. It could happen in case of allocation errors
in vc2_encode_init().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=31da97b08325a338db7931428ba0625d4e61f168
---

 libavcodec/vc2enc_dwt.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavcodec/vc2enc_dwt.c b/libavcodec/vc2enc_dwt.c
index a8d3f1c669..441af040ec 100644
--- a/libavcodec/vc2enc_dwt.c
+++ b/libavcodec/vc2enc_dwt.c
@@ -276,6 +276,8 @@ av_cold int ff_vc2enc_init_transforms(VC2TransformContext *s, int p_stride,
 
 av_cold void ff_vc2enc_free_transforms(VC2TransformContext *s)
 {
-    av_free(s->buffer - s->padding);
-    s->buffer = NULL;
+    if (s->buffer) {
+        av_free(s->buffer - s->padding);
+        s->buffer = NULL;
+    }
 }