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 <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2018-01-15 23:46:44 +01:00
parent 1bfc1aa004
commit a026a3efae
1 changed files with 1 additions and 1 deletions

View File

@ -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;
}