[FFmpeg-devel] [PATCH 6/6] avformat/hls: Fix DoS due to infinite loop

Michael Niedermayer michael at niedermayer.cc
Fri Aug 25 02:15:32 EEST 2017


Fixes: loop.m3u

The max iteration count of 10000 is arbitrary and ideas for a better solution are welcome

Found-by: Xiaohei and Wangchu from Alibaba Security Team
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/hls.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavformat/hls.c b/libavformat/hls.c
index 01731bd36b..26f4ebd965 100644
--- a/libavformat/hls.c
+++ b/libavformat/hls.c
@@ -1263,6 +1263,7 @@ static int read_data(void *opaque, uint8_t *buf, int buf_size)
     HLSContext *c = v->parent->priv_data;
     int ret, i;
     int just_opened = 0;
+    int reload_count = 0;
 
 restart:
     if (!v->needed)
@@ -1294,6 +1295,9 @@ restart:
         reload_interval = default_reload_interval(v);
 
 reload:
+        reload_count++;
+        if (reload_count > 10000)
+            return AVERROR_EOF;
         if (!v->finished &&
             av_gettime_relative() - v->last_load_time >= reload_interval) {
             if ((ret = parse_playlist(c, v->url, v, NULL)) < 0) {
-- 
2.14.1



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