avcodec/iff: Move index use after check in decodeplane8()
authorMichael Niedermayer <michael@niedermayer.cc>
Tue, 29 Oct 2019 18:12:23 +0000 (19:12 +0100)
committerMichael Niedermayer <michael@niedermayer.cc>
Wed, 20 Nov 2019 14:50:15 +0000 (15:50 +0100)
Fixes: index 9 out of bounds for type 'const uint64_t [8][256]'
Fixes: 18409/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5767030560522240
Fixes: 18720/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5651995784642560

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

index 500f9bf..0656ae5 100644 (file)
@@ -456,11 +456,12 @@ static av_cold int decode_init(AVCodecContext *avctx)
  */
 static void decodeplane8(uint8_t *dst, const uint8_t *buf, int buf_size, int plane)
 {
-    const uint64_t *lut = plane8_lut[plane];
+    const uint64_t *lut;
     if (plane >= 8) {
         av_log(NULL, AV_LOG_WARNING, "Ignoring extra planes beyond 8\n");
         return;
     }
+    lut = plane8_lut[plane];
     do {
         uint64_t v = AV_RN64A(dst) | lut[*buf++];
         AV_WN64A(dst, v);