avcodec/jpeglsdec: Apply transform only to initialized lines

Fixes: Timeout (110sec -> 1sec)
Fixes: 17123/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AMV_fuzzer-5636452758585344

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 2019-09-19 18:52:50 +02:00
parent fe7fbf3a22
commit 675c6d1e17

View File

@ -352,6 +352,7 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
uint8_t *zero, *last, *cur;
JLSState *state;
int off = 0, stride = 1, width, shift, ret = 0;
int decoded_height = 0;
zero = av_mallocz(s->picture_ptr->linesize[0]);
if (!zero)
@ -427,6 +428,7 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
skip_bits(&s->gb, 16); /* skip RSTn */
}
}
decoded_height = i;
} else if (ilv == 1) { /* line interleaving */
int j;
int Rc[3] = { 0, 0, 0 };
@ -452,6 +454,7 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
last = cur;
cur += s->picture_ptr->linesize[0];
}
decoded_height = i;
} else if (ilv == 2) { /* sample interleaving */
avpriv_report_missing_feature(s->avctx, "Sample interleaved images");
ret = AVERROR_PATCHWELCOME;
@ -517,7 +520,7 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
if (s->bits <= 8) {
uint8_t *src = s->picture_ptr->data[0];
for (i = 0; i < s->height; i++) {
for (i = 0; i < decoded_height; i++) {
for (x = off; x < w; x += stride)
src[x] <<= shift;
src += s->picture_ptr->linesize[0];
@ -525,7 +528,7 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
} else {
uint16_t *src = (uint16_t *)s->picture_ptr->data[0];
for (i = 0; i < s->height; i++) {
for (i = 0; i < decoded_height; i++) {
for (x = 0; x < w; x++)
src[x] <<= shift;
src += s->picture_ptr->linesize[0] / 2;