diff mbox

[FFmpeg-devel,2/2] avcodec/tiff: Detect infinite retry loop

Message ID 20190808083646.18391-2-michael@niedermayer.cc
State New
Headers show

Commit Message

Michael Niedermayer Aug. 8, 2019, 8:36 a.m. UTC 
Fixes: Timeout (Infinite -> 26ms)
Fixes: 15706/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-5114674904825856

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/tiff.c | 6 ++++++
 1 file changed, 6 insertions(+)
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Patch

diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index c520d7df83..e3bdd8612e 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -37,6 +37,7 @@ 
 #include "libavutil/avstring.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/imgutils.h"
+#include "libavutil/loop_detector.h"
 #include "libavutil/opt.h"
 #include "avcodec.h"
 #include "bytestream.h"
@@ -1407,6 +1408,7 @@  static int decode_frame(AVCodecContext *avctx,
     GetByteContext stripsizes;
     GetByteContext stripdata;
     int retry_for_subifd, retry_for_page;
+    AVSimpleLoopDetector loop_detector = {0};
 
     bytestream2_init(&s->gb, avpkt->data, avpkt->size);
 
@@ -1467,6 +1469,10 @@  again:
             av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n");
             return AVERROR_INVALIDDATA;
         }
+        if (av_is_loop(&loop_detector, off, INT64_MAX)) {
+            av_log(avctx, AV_LOG_ERROR, "too many retries\n");
+            return AVERROR_INVALIDDATA;
+        }
         s->sub_ifd = 0;
         goto again;
     }