[FFmpeg-devel] [PATCH 1/2] avcodec/diracdec: Propagate errors from codeblock()
Michael Niedermayer
michael at niedermayer.cc
Fri Sep 14 02:51:55 EEST 2018
Consider a component to be damaged if more than 50% of its subbands are damaged
Fixes: Timeout (part 1 of 2)
Fixes: 9774/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5748957085958144
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
libavcodec/diracdec.c | 47 +++++++++++++++++++++++++++++--------------
1 file changed, 32 insertions(+), 15 deletions(-)
diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index 9a417caec5..cbd7fd1532 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -488,7 +488,7 @@ UNPACK_ARITH(10, int32_t)
* Decode the coeffs in the rectangle defined by left, right, top, bottom
* [DIRAC_STD] 13.4.3.2 Codeblock unpacking loop. codeblock()
*/
-static inline void codeblock(DiracContext *s, SubBand *b,
+static inline int codeblock(DiracContext *s, SubBand *b,
GetBitContext *gb, DiracArith *c,
int left, int right, int top, int bottom,
int blockcnt_one, int is_arith)
@@ -505,7 +505,7 @@ static inline void codeblock(DiracContext *s, SubBand *b,
zero_block = get_bits1(gb);
if (zero_block)
- return;
+ return 0;
}
if (s->codeblock_mode && !(s->old_delta_quant && blockcnt_one)) {
@@ -516,7 +516,7 @@ static inline void codeblock(DiracContext *s, SubBand *b,
quant = dirac_get_se_golomb(gb);
if (quant > INT_MAX - b->quant || b->quant + quant < 0) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid quant\n");
- return;
+ return AVERROR_INVALIDDATA;
}
b->quant += quant;
}
@@ -524,7 +524,7 @@ static inline void codeblock(DiracContext *s, SubBand *b,
if (b->quant > (DIRAC_MAX_QUANT_INDEX - 1)) {
av_log(s->avctx, AV_LOG_ERROR, "Unsupported quant %d\n", b->quant);
b->quant = 0;
- return;
+ return AVERROR_INVALIDDATA;
}
qfactor = ff_dirac_qscale_tab[b->quant];
@@ -559,6 +559,7 @@ static inline void codeblock(DiracContext *s, SubBand *b,
buf += b->stride;
}
}
+ return 0;
}
/**
@@ -593,7 +594,7 @@ INTRA_DC_PRED(10, uint32_t)
* Dirac Specification ->
* 13.4.2 Non-skipped subbands. subband_coeffs()
*/
-static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b, int is_arith)
+static av_always_inline int decode_subband_internal(DiracContext *s, SubBand *b, int is_arith)
{
int cb_x, cb_y, left, right, top, bottom;
DiracArith c;
@@ -601,9 +602,10 @@ static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b
int cb_width = s->codeblock[b->level + (b->orientation != subband_ll)].width;
int cb_height = s->codeblock[b->level + (b->orientation != subband_ll)].height;
int blockcnt_one = (cb_width + cb_height) == 2;
+ int ret;
if (!b->length)
- return;
+ return 0;
init_get_bits8(&gb, b->coeff_data, b->length);
@@ -616,7 +618,9 @@ static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b
left = 0;
for (cb_x = 0; cb_x < cb_width; cb_x++) {
right = (b->width * (cb_x+1LL)) / cb_width;
- codeblock(s, b, &gb, &c, left, right, top, bottom, blockcnt_one, is_arith);
+ ret = codeblock(s, b, &gb, &c, left, right, top, bottom, blockcnt_one, is_arith);
+ if (ret < 0)
+ return ret;
left = right;
}
top = bottom;
@@ -629,33 +633,35 @@ static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b
intra_dc_prediction_8(b);
}
}
+ return 0;
}
static int decode_subband_arith(AVCodecContext *avctx, void *b)
{
DiracContext *s = avctx->priv_data;
- decode_subband_internal(s, b, 1);
- return 0;
+ return decode_subband_internal(s, b, 1);
}
static int decode_subband_golomb(AVCodecContext *avctx, void *arg)
{
DiracContext *s = avctx->priv_data;
SubBand **b = arg;
- decode_subband_internal(s, *b, 0);
- return 0;
+ return decode_subband_internal(s, *b, 0);
}
/**
* Dirac Specification ->
* [DIRAC_STD] 13.4.1 core_transform_data()
*/
-static void decode_component(DiracContext *s, int comp)
+static int decode_component(DiracContext *s, int comp)
{
AVCodecContext *avctx = s->avctx;
SubBand *bands[3*MAX_DWT_LEVELS+1];
enum dirac_subband orientation;
int level, num_bands = 0;
+ int ret[3*MAX_DWT_LEVELS+1];
+ int i;
+ int damaged_count = 0;
/* Unpack all subbands at all levels. */
for (level = 0; level < s->wavelet_depth; level++) {
@@ -677,11 +683,20 @@ static void decode_component(DiracContext *s, int comp)
/* arithmetic coding has inter-level dependencies, so we can only execute one level at a time */
if (s->is_arith)
avctx->execute(avctx, decode_subband_arith, &s->plane[comp].band[level][!!level],
- NULL, 4-!!level, sizeof(SubBand));
+ ret + 3*level + !!level, 4-!!level, sizeof(SubBand));
}
/* golomb coding has no inter-level dependencies, so we can execute all subbands in parallel */
if (!s->is_arith)
- avctx->execute(avctx, decode_subband_golomb, bands, NULL, num_bands, sizeof(SubBand*));
+ avctx->execute(avctx, decode_subband_golomb, bands, ret, num_bands, sizeof(SubBand*));
+
+ for (i = 0; i < s->wavelet_depth * 3 + 1; i++) {
+ if (ret[i] < 0)
+ damaged_count++;
+ }
+ if (damaged_count > (s->wavelet_depth * 3 + 1) /2)
+ return AVERROR_INVALIDDATA;
+
+ return 0;
}
#define PARSE_VALUES(type, x, gb, ebits, buf1, buf2) \
@@ -1867,7 +1882,9 @@ static int dirac_decode_frame_internal(DiracContext *s)
if (!s->zero_res && !s->low_delay)
{
memset(p->idwt.buf, 0, p->idwt.stride * p->idwt.height);
- decode_component(s, comp); /* [DIRAC_STD] 13.4.1 core_transform_data() */
+ ret = decode_component(s, comp); /* [DIRAC_STD] 13.4.1 core_transform_data() */
+ if (ret < 0)
+ return ret;
}
ret = ff_spatial_idwt_init(&d, &p->idwt, s->wavelet_idx+2,
s->wavelet_depth, s->bit_depth);
--
2.18.0
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