avcodec/jpeg2000: Dynamically allocate codeblock data

Fixes: OOM
Fixes: 3541/clusterfuzz-testcase-minimized-6469958596820992

Adds support for decoding codeblock data larger than 8kb
Reduces decoder memory consumption

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 2017-11-18 01:33:18 +01:00
parent e8e9306b4f
commit 3d5822d9cf
4 changed files with 37 additions and 9 deletions

View File

@ -663,7 +663,8 @@ static void encode_cblk(Jpeg2000EncoderContext *s, Jpeg2000T1Context *t1, Jpeg20
bpno = cblk->nonzerobits - 1;
}
ff_mqc_initenc(&t1->mqc, cblk->data);
cblk->data[0] = 0;
ff_mqc_initenc(&t1->mqc, cblk->data + 1);
for (passno = 0; bpno >= 0; passno++){
nmsedec=0;
@ -796,7 +797,7 @@ static int encode_packet(Jpeg2000EncoderContext *s, Jpeg2000ResLevel *rlevel, in
if (cblk->ninclpasses){
if (s->buf_end - s->buf < cblk->passes[cblk->ninclpasses-1].rate)
return -1;
bytestream_put_buffer(&s->buf, cblk->data, cblk->passes[cblk->ninclpasses-1].rate
bytestream_put_buffer(&s->buf, cblk->data + 1, cblk->passes[cblk->ninclpasses-1].rate
- cblk->passes[cblk->ninclpasses-1].flushed_len);
bytestream_put_buffer(&s->buf, cblk->passes[cblk->ninclpasses-1].flushed,
cblk->passes[cblk->ninclpasses-1].flushed_len);
@ -937,6 +938,9 @@ static int encode_tile(Jpeg2000EncoderContext *s, Jpeg2000Tile *tile, int tileno
}
}
}
prec->cblk[cblkno].data = av_malloc(1 + 8192);
if (!prec->cblk[cblkno].data)
return AVERROR(ENOMEM);
encode_cblk(s, &t1, prec->cblk + cblkno, tile, xx1 - xx0, yy1 - yy0,
bandpos, codsty->nreslevels - reslevelno - 1);
xx0 = xx1;

View File

@ -357,7 +357,6 @@ static int init_prec(Jpeg2000Band *band,
comp->reslevel[reslevelno-1].coord[1][0];
}
cblk->zero = 0;
cblk->lblock = 3;
cblk->length = 0;
memset(cblk->lengthinc, 0, sizeof(cblk->lengthinc));
@ -598,9 +597,18 @@ void ff_jpeg2000_cleanup(Jpeg2000Component *comp, Jpeg2000CodingStyle *codsty)
for (precno = 0; precno < reslevel->num_precincts_x * reslevel->num_precincts_y; precno++) {
if (band->prec) {
Jpeg2000Prec *prec = band->prec + precno;
int nb_code_blocks = prec->nb_codeblocks_height * prec->nb_codeblocks_width;
av_freep(&prec->zerobits);
av_freep(&prec->cblkincl);
av_freep(&prec->cblk);
if (prec->cblk) {
int cblkno;
for (cblkno = 0; cblkno < nb_code_blocks; cblkno ++) {
Jpeg2000Cblk *cblk = &prec->cblk[cblkno];
av_freep(&cblk->data);
}
av_freep(&prec->cblk);
}
}
}

View File

@ -168,8 +168,8 @@ typedef struct Jpeg2000Cblk {
uint16_t lengthinc[JPEG2000_MAX_PASSES];
uint8_t nb_lengthinc;
uint8_t lblock;
uint8_t zero;
uint8_t data[8192];
uint8_t *data;
size_t data_allocated;
int nb_terminations;
int nb_terminationsinc;
int data_start[JPEG2000_MAX_PASSES];

View File

@ -1001,10 +1001,18 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
if ((ret = get_bits(s, av_log2(newpasses1) + cblk->lblock)) < 0)
return ret;
if (ret > sizeof(cblk->data)) {
if (ret > cblk->data_allocated) {
size_t new_size = FFMAX(2*cblk->data_allocated, ret);
void *new = av_realloc(cblk->data, new_size);
if (new) {
cblk->data = new;
cblk->data_allocated = new_size;
}
}
if (ret > cblk->data_allocated) {
avpriv_request_sample(s->avctx,
"Block with lengthinc greater than %"SIZE_SPECIFIER"",
sizeof(cblk->data));
cblk->data_allocated);
return AVERROR_PATCHWELCOME;
}
cblk->lengthinc[cblk->nb_lengthinc++] = ret;
@ -1030,8 +1038,16 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
for (cblkno = 0; cblkno < nb_code_blocks; cblkno++) {
Jpeg2000Cblk *cblk = prec->cblk + cblkno;
for (cwsno = 0; cwsno < cblk->nb_lengthinc; cwsno ++) {
if (cblk->data_allocated < cblk->length + cblk->lengthinc[cwsno] + 4) {
size_t new_size = FFMAX(2*cblk->data_allocated, cblk->length + cblk->lengthinc[cwsno] + 4);
void *new = av_realloc(cblk->data, new_size);
if (new) {
cblk->data = new;
cblk->data_allocated = new_size;
}
}
if ( bytestream2_get_bytes_left(&s->g) < cblk->lengthinc[cwsno]
|| sizeof(cblk->data) < cblk->length + cblk->lengthinc[cwsno] + 4
|| cblk->data_allocated < cblk->length + cblk->lengthinc[cwsno] + 4
) {
av_log(s->avctx, AV_LOG_ERROR,
"Block length %"PRIu16" or lengthinc %d is too large, left %d\n",