[FFmpeg-cvslog] avcodec/bitstream_filters: check the input argument of av_bsf_get_by_name() for NULL

[James Almer]

ffmpeg | branch: release/4.0 | James Almer <jamrial at gmail.com> | Sat Jul 28 00:51:57 2018 -0300| [9cc5337247b2eab04966af71057381d95f852e55] | committer: James Almer

avcodec/bitstream_filters: check the input argument of av_bsf_get_by_name() for NULL

Fixes crashes like "ffmpeg -h bsf" caused by passing NULL to strcmp()

Signed-off-by: James Almer <jamrial at gmail.com>
(cherry picked from commit 3258cc6507a2012d54889ce5f8efbde7e81d927d)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9cc5337247b2eab04966af71057381d95f852e55
---

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

diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c
index 18b698a85f..8bdc834ab9 100644
--- a/libavcodec/bitstream_filters.c
+++ b/libavcodec/bitstream_filters.c
@@ -77,6 +77,9 @@ const AVBitStreamFilter *av_bsf_get_by_name(const char *name)
     const AVBitStreamFilter *f = NULL;
     void *i = 0;
 
+    if (!name)
+        return NULL;
+
     while ((f = av_bsf_iterate(&i))) {
         if (!strcmp(f->name, name))
             return f;