[FFmpeg-cvslog] avcodec/aacdec_template: skip apply_tns() if max_sfb is 0 (from previous header decode failure)

[Michael Niedermayer]

ffmpeg | branch: release/4.1 | Michael Niedermayer <michael at niedermayer.cc> | Sat May 18 10:37:26 2019 +0200| [5fbc6dcdccf16996ce79f17f8c0ae37069447aed] | committer: Michael Niedermayer

avcodec/aacdec_template: skip apply_tns() if max_sfb is 0 (from previous header decode failure)

Fixes: NULL pointer dereference
Fixes: 14723/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AAC_LATM_fuzzer-5654612436058112
Fixes: 14724/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AAC_LATM_fuzzer-5712607111020544

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit cf3156e762bbd3fbaf9da53f3ef1ea6d1bad2ec5)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5fbc6dcdccf16996ce79f17f8c0ae37069447aed
---

 libavcodec/aacdec_template.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index e88a26fda9..05505c0359 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -2492,6 +2492,9 @@ static void apply_tns(INTFLOAT coef_param[1024], TemporalNoiseShaping *tns,
     INTFLOAT tmp[TNS_MAX_ORDER+1];
     UINTFLOAT *coef = coef_param;
 
+    if(!mmm)
+        return;
+
     for (w = 0; w < ics->num_windows; w++) {
         bottom = ics->num_swb;
         for (filt = 0; filt < tns->n_filt[w]; filt++) {