mjpegdec: Do not assume unused plane pointer are NULL.

We do neither document nor check such a requirement
and for application-provided get_buffer2 they could
contain the result of a malloc(0) or whatever value
they had previously.
This fixes a use-after-free in e.g. MPlayer:
https://trac.mplayerhq.hu/ticket/2262
We might want to consider changing the (documented)
API in addition though.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
This commit is contained in:
Reimar Döffinger 2016-02-26 00:11:12 +01:00
parent 0f199f0ad0
commit 45fa03b1f9
1 changed files with 8 additions and 3 deletions

View File

@ -2268,7 +2268,8 @@ the_end:
avctx->pix_fmt == AV_PIX_FMT_GBRAP
);
avcodec_get_chroma_sub_sample(s->avctx->pix_fmt, &hshift, &vshift);
for (p = 0; p<4; p++) {
av_assert0(s->nb_components == av_pix_fmt_count_planes(s->picture_ptr->format));
for (p = 0; p<s->nb_components; p++) {
uint8_t *line = s->picture_ptr->data[p];
int w = s->width;
int h = s->height;
@ -2326,7 +2327,8 @@ the_end:
avctx->pix_fmt == AV_PIX_FMT_GBRAP
);
avcodec_get_chroma_sub_sample(s->avctx->pix_fmt, &hshift, &vshift);
for (p = 0; p < 4; p++) {
av_assert0(s->nb_components == av_pix_fmt_count_planes(s->picture_ptr->format));
for (p = 0; p < s->nb_components; p++) {
uint8_t *dst;
int w = s->width;
int h = s->height;
@ -2353,7 +2355,8 @@ the_end:
if (s->flipped) {
int j;
avcodec_get_chroma_sub_sample(s->avctx->pix_fmt, &hshift, &vshift);
for (index=0; index<4; index++) {
av_assert0(s->nb_components == av_pix_fmt_count_planes(s->picture_ptr->format));
for (index=0; index<s->nb_components; index++) {
uint8_t *dst = s->picture_ptr->data[index];
int w = s->picture_ptr->width;
int h = s->picture_ptr->height;
@ -2375,6 +2378,7 @@ the_end:
if (s->adobe_transform == 0 && s->avctx->pix_fmt == AV_PIX_FMT_GBRAP) {
int w = s->picture_ptr->width;
int h = s->picture_ptr->height;
av_assert0(s->nb_components == 4);
for (i=0; i<h; i++) {
int j;
uint8_t *dst[4];
@ -2397,6 +2401,7 @@ the_end:
if (s->adobe_transform == 2 && s->avctx->pix_fmt == AV_PIX_FMT_YUVA444P) {
int w = s->picture_ptr->width;
int h = s->picture_ptr->height;
av_assert0(s->nb_components == 4);
for (i=0; i<h; i++) {
int j;
uint8_t *dst[4];