From e1255789941d213a8e193469d0687946c9fa4a63 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 25 Aug 2019 18:22:50 +0200 Subject: [PATCH] avcodec/alsdec: Check k from being outside what our implementation can handle The specification does not seem to list what the maximum valid value is Fixes: shift exponent 32 is too large for 32-bit type 'unsigned int' Fixes: 16268/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALS_fuzzer-5638164544225280 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/alsdec.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c index f8d10df8c6..a53c170d18 100644 --- a/libavcodec/alsdec.c +++ b/libavcodec/alsdec.c @@ -833,6 +833,9 @@ static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd) k [sb] = s[sb] > b ? s[sb] - b : 0; delta[sb] = 5 - s[sb] + k[sb]; + if (k[sb] >= 32) + return AVERROR_INVALIDDATA; + ff_bgmc_decode(gb, sb_len, current_res, delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);