[FFmpeg-cvslog] fftools/ffmpeg: avoid possible invalid reads with short -tag values

[Anton Khirnov]

ffmpeg | branch: release/6.0 | Anton Khirnov <anton at khirnov.net> | Thu Apr 13 15:56:54 2023 +0200| [8f61cbf1b9249a732b40fc26fc4f84e390f6e2d4] | committer: Anton Khirnov

fftools/ffmpeg: avoid possible invalid reads with short -tag values

Fixes #10319 and #10309.

(cherry picked from commit 89c9a3ac3542c3684e511607d88b265bfa6aa64f)
Signed-off-by: Anton Khirnov <anton at khirnov.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8f61cbf1b9249a732b40fc26fc4f84e390f6e2d4
---

 fftools/ffmpeg_demux.c    | 8 ++++++--
 fftools/ffmpeg_mux_init.c | 7 +++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/fftools/ffmpeg_demux.c b/fftools/ffmpeg_demux.c
index ffece60720..938ec09e3d 100644
--- a/fftools/ffmpeg_demux.c
+++ b/fftools/ffmpeg_demux.c
@@ -628,8 +628,12 @@ static void add_input_streams(const OptionsContext *o, Demuxer *d)
         MATCH_PER_STREAM_OPT(codec_tags, str, codec_tag, ic, st);
         if (codec_tag) {
             uint32_t tag = strtol(codec_tag, &next, 0);
-            if (*next)
-                tag = AV_RL32(codec_tag);
+            if (*next) {
+                uint8_t buf[4] = { 0 };
+                memcpy(buf, codec_tag, FFMIN(sizeof(buf), strlen(codec_tag)));
+                tag = AV_RL32(buf);
+            }
+
             st->codecpar->codec_tag = tag;
         }
 
diff --git a/fftools/ffmpeg_mux_init.c b/fftools/ffmpeg_mux_init.c
index 09d24ba8e5..e42d5ff26a 100644
--- a/fftools/ffmpeg_mux_init.c
+++ b/fftools/ffmpeg_mux_init.c
@@ -606,8 +606,11 @@ static OutputStream *new_output_stream(Muxer *mux, const OptionsContext *o,
     MATCH_PER_STREAM_OPT(codec_tags, str, codec_tag, oc, st);
     if (codec_tag) {
         uint32_t tag = strtol(codec_tag, &next, 0);
-        if (*next)
-            tag = AV_RL32(codec_tag);
+        if (*next) {
+            uint8_t buf[4] = { 0 };
+            memcpy(buf, codec_tag, FFMIN(sizeof(buf), strlen(codec_tag)));
+            tag = AV_RL32(buf);
+        }
         ost->st->codecpar->codec_tag = tag;
         if (ost->enc_ctx)
             ost->enc_ctx->codec_tag = tag;