avcodec/4xm: Fix vlc memleak

Fixes: memleak
Fixes: 15297/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FOURXM_fuzzer-5746203548975104
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/4xm.c b/libavcodec/4xm.c
index 2b88c899d0a5d0f55eb0ca87874a2946df0360ec..89120aa8fb8ac3186f91301ffc4048321451bb94 100644 (file)
--- a/libavcodec/4xm.c
+++ b/libavcodec/4xm.c
@@ -697,6 +697,7 @@ static const uint8_t *read_huffman_tables(FourXContext *f,
         len_tab[j]  = len;
     }
 
+    ff_free_vlc(&f->pre_vlc);
     if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, len_tab, 1, 1,
                  bits_tab, 4, 4, 0))
         return NULL;