From a026a3efaeb9c2026668dccbbda339a21ab3206b Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 15 Jan 2018 23:46:44 +0100 Subject: [PATCH] avcodec/hevc_cabac: Check prefix so as to avoid invalid shifts in coeff_abs_level_remaining_decode() I suspect that this can be limited tighter, but i failed to find anything in the spec that would confirm that. Fixes: 4833/clusterfuzz-testcase-minimized-5302840101699584 Fixes: runtime error: left shift of 134217730 by 4 places cannot be represented in type 'int' Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/hevc_cabac.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/hevc_cabac.c b/libavcodec/hevc_cabac.c index 743168500c..faa36d5459 100644 --- a/libavcodec/hevc_cabac.c +++ b/libavcodec/hevc_cabac.c @@ -998,7 +998,7 @@ static av_always_inline int coeff_abs_level_remaining_decode(HEVCContext *s, int } else { int prefix_minus3 = prefix - 3; - if (prefix == CABAC_MAX_BIN) { + if (prefix == CABAC_MAX_BIN || prefix_minus3 + rc_rice_param >= 31) { av_log(s->avctx, AV_LOG_ERROR, "CABAC_MAX_BIN : %d\n", prefix); return 0; }