[FFmpeg-cvslog] avformat/aaxdec: Check string before strcmp()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Oct 23 18:05:23 2020 +0200| [fcc263caa9e11a1f94431a6d356a48003c636ef6] | committer: Michael Niedermayer

avformat/aaxdec: Check string before strcmp()

Fixes: NULL ptr dereference
Fixes: 26508/clusterfuzz-testcase-minimized-ffmpeg_dem_AAX_fuzzer-5694725249826816

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=fcc263caa9e11a1f94431a6d356a48003c636ef6
---

 libavformat/aaxdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/aaxdec.c b/libavformat/aaxdec.c
index 3db6e9bc6d..7d10e805ca 100644
--- a/libavformat/aaxdec.c
+++ b/libavformat/aaxdec.c
@@ -232,7 +232,7 @@ static int aax_read_header(AVFormatContext *s)
         int64_t col_offset;
         int flag, type;
 
-        if (strcmp(a->xcolumns[c].name, "data"))
+        if (!a->xcolumns[c].name || strcmp(a->xcolumns[c].name, "data"))
             continue;
 
         type = a->xcolumns[c].type;