From 2c874548d663225a61b9c25a8b2ce490d26b65fa Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Tue, 27 Jun 2017 14:11:00 +0200
Subject: [PATCH] avcodec/hevcdec: do basic validity check on
delta_chroma_weight and offset
Fixes: runtime error: signed integer overflow: 2147483520 + 128 cannot be represented in type 'int'
Fixes: 2385/clusterfuzz-testcase-minimized-6594333576790016
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
libavcodec/hevcdec.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index f6bc5efa966..095564b3681 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -139,7 +139,7 @@ fail:
return AVERROR(ENOMEM);
}
-static void pred_weight_table(HEVCContext *s, GetBitContext *gb)
+static int pred_weight_table(HEVCContext *s, GetBitContext *gb)
{
int i = 0;
int j = 0;
@@ -182,6 +182,12 @@ static void pred_weight_table(HEVCContext *s, GetBitContext *gb)
for (j = 0; j < 2; j++) {
int delta_chroma_weight_l0 = get_se_golomb(gb);
int delta_chroma_offset_l0 = get_se_golomb(gb);
+
+ if ( (int8_t)delta_chroma_weight_l0 != delta_chroma_weight_l0
+ || delta_chroma_offset_l0 < -(1<<17) || delta_chroma_offset_l0 > (1<<17)) {
+ return AVERROR_INVALIDDATA;
+ }
+
s->sh.chroma_weight_l0[i][j] = (1 << s->sh.chroma_log2_weight_denom) + delta_chroma_weight_l0;
s->sh.chroma_offset_l0[i][j] = av_clip((delta_chroma_offset_l0 - ((128 * s->sh.chroma_weight_l0[i][j])
>> s->sh.chroma_log2_weight_denom) + 128), -128, 127);
@@ -218,6 +224,12 @@ static void pred_weight_table(HEVCContext *s, GetBitContext *gb)
for (j = 0; j < 2; j++) {
int delta_chroma_weight_l1 = get_se_golomb(gb);
int delta_chroma_offset_l1 = get_se_golomb(gb);
+
+ if ( (int8_t)delta_chroma_weight_l1 != delta_chroma_weight_l1
+ || delta_chroma_offset_l1 < -(1<<17) || delta_chroma_offset_l1 > (1<<17)) {
+ return AVERROR_INVALIDDATA;
+ }
+
s->sh.chroma_weight_l1[i][j] = (1 << s->sh.chroma_log2_weight_denom) + delta_chroma_weight_l1;
s->sh.chroma_offset_l1[i][j] = av_clip((delta_chroma_offset_l1 - ((128 * s->sh.chroma_weight_l1[i][j])
>> s->sh.chroma_log2_weight_denom) + 128), -128, 127);
@@ -230,6 +242,7 @@ static void pred_weight_table(HEVCContext *s, GetBitContext *gb)
}
}
}
+ return 0;
}
static int decode_lt_rps(HEVCContext *s, LongTermRPS *rps, GetBitContext *gb)
@@ -692,7 +705,9 @@ static int hls_slice_header(HEVCContext *s)
if ((s->ps.pps->weighted_pred_flag && sh->slice_type == HEVC_SLICE_P) ||
(s->ps.pps->weighted_bipred_flag && sh->slice_type == HEVC_SLICE_B)) {
- pred_weight_table(s, gb);
+ int ret = pred_weight_table(s, gb);
+ if (ret < 0)
+ return ret;
}
sh->max_num_merge_cand = 5 - get_ue_golomb_long(gb);
--
GitLab