avcodec/snappy: Sanity check bytestream2_get_levarint()

Fixes: left shift of 79 by 28 places cannot be represented in type 'int' Fixes: 20202/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HAP_fuzzer-5719004081815552 Fixes: 20219/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HAP_fuzzer-5641738677125120 Fixes: 20389/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HAP_fuzzer-5680721517871104 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
5 years ago · be54da2117
parent 53aa76686e
commit be54da2117
1 changed files with 2 additions and 0 deletions
--- a/libavcodec/snappy.c
+++ b/libavcodec/snappy.c
@ -39,6 +39,8 @@ static int64_t bytestream2_get_levarint(GetByteContext *gb)

    do {
        tmp = bytestream2_get_byte(gb);
+        if (shift > 31 || ((tmp & 127LL) << shift) > INT_MAX)
+            return AVERROR_INVALIDDATA;
        val |= (tmp & 127) << shift;
        shift += 7;
    } while (tmp & 128);