[FFmpeg-cvslog] avcodec/eatgq: : Check index increments in tgq_decode_block()
Michael Niedermayer
git at videolan.org
Thu Feb 23 23:20:38 EET 2023
ffmpeg | branch: release/5.1 | Michael Niedermayer <michael at niedermayer.cc> | Wed Jan 11 23:05:55 2023 +0100| [a34fe535e41162041f47b4c2baa37d33c7949f67] | committer: Michael Niedermayer
avcodec/eatgq: : Check index increments in tgq_decode_block()
Fixes: out of array access
Fixes: 48567/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EATGQ_fuzzer-6743211456724992
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit e7755b433e913e32bb061f17d5ecfcbcfef995b7)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a34fe535e41162041f47b4c2baa37d33c7949f67
---
libavcodec/eatgq.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/libavcodec/eatgq.c b/libavcodec/eatgq.c
index 2e9d2fe13c..eca93fd8a2 100644
--- a/libavcodec/eatgq.c
+++ b/libavcodec/eatgq.c
@@ -62,7 +62,7 @@ static av_cold int tgq_decode_init(AVCodecContext *avctx)
return 0;
}
-static void tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb)
+static int tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb)
{
uint8_t *perm = s->scantable.permutated;
int i, j, value;
@@ -70,6 +70,8 @@ static void tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb
for (i = 1; i < 64;) {
switch (show_bits(gb, 3)) {
case 4:
+ if (i >= 63)
+ return AVERROR_INVALIDDATA;
block[perm[i++]] = 0;
case 0:
block[perm[i++]] = 0;
@@ -79,6 +81,8 @@ static void tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb
case 1:
skip_bits(gb, 2);
value = get_bits(gb, 6);
+ if (value > 64 - i)
+ return AVERROR_INVALIDDATA;
for (j = 0; j < value; j++)
block[perm[i++]] = 0;
break;
@@ -106,6 +110,7 @@ static void tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb
}
}
block[0] += 128 << 4;
+ return 0;
}
static void tgq_idct_put_mb(TgqContext *s, int16_t (*block)[64], AVFrame *frame,
@@ -165,8 +170,11 @@ static int tgq_decode_mb(TgqContext *s, AVFrame *frame, int mb_y, int mb_x)
if (ret < 0)
return ret;
- for (i = 0; i < 6; i++)
- tgq_decode_block(s, s->block[i], &gb);
+ for (i = 0; i < 6; i++) {
+ int ret = tgq_decode_block(s, s->block[i], &gb);
+ if (ret < 0)
+ return ret;
+ }
tgq_idct_put_mb(s, s->block, frame, mb_x, mb_y);
bytestream2_skip(&s->gb, mode);
} else {
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