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avcodec/cfhd: Keep track of which subbands have been read

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This avoids use of uninitialized data
also several checks are inside the band reading code
so it is important that it is run at least once

Fixes: out of array accesses
Fixes: 28209/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-5684714694377472
Fixes: 32124/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-5425980681355264
Fixes: 30519/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-4558757155700736

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 2021-04-03 16:04:48 +02:00
parent 3b88c88fa1
commit da8c86dd8b
2 changed files with 27 additions and 0 deletions
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26
libavcodec/cfhd.c
View File

@ -221,6 +221,7 @@ static void free_buffers(CFHDContext *s)
int i, j;
for (i = 0; i < FF_ARRAY_ELEMS(s->plane); i++) {
Plane *p = &s->plane[i];
av_freep(&s->plane[i].idwt_buf);
av_freep(&s->plane[i].idwt_tmp);
s->plane[i].idwt_size = 0;
@ -230,6 +231,12 @@ static void free_buffers(CFHDContext *s)
for (j = 0; j < 10; j++)
s->plane[i].l_h[j] = NULL;
for (j = 0; j < DWT_LEVELS_3D; j++)
p->band[j][0].read_ok =
p->band[j][1].read_ok =
p->band[j][2].read_ok =
p->band[j][3].read_ok = 0;
}
s->a_height = 0;
s->a_width = 0;
@ -759,6 +766,8 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
lowpass_width * sizeof(*coeff_data));
}
s->plane[s->channel_num].band[0][0].read_ok = 1;
av_log(avctx, AV_LOG_DEBUG, "Lowpass coefficients %d\n", lowpass_width * lowpass_height);
}
@ -891,6 +900,7 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
bytestream2_seek(&gb, bytes, SEEK_CUR);
av_log(avctx, AV_LOG_DEBUG, "End subband coeffs %i extra %i\n", count, count - expected);
s->plane[s->channel_num].band[s->level][s->subband_num].read_ok = 1;
finish:
if (s->subband_num_actual != 255)
s->codebook = 0;
@ -919,6 +929,22 @@ finish:
goto end;
}
for (plane = 0; plane < s->planes; plane++) {
int o, level;
for (level = 0; level < (s->transform_type == 0 ? DWT_LEVELS : DWT_LEVELS_3D) ; level++) {
if (s->transform_type == 2)
if (level == 2 || level == 5)
continue;
for (o = !!level; o < 4 ; o++) {
if (!s->plane[plane].band[level][o].read_ok) {
ret = AVERROR_INVALIDDATA;
goto end;
}
}
}
}
if (s->transform_type == 0 && s->sample_type != 1) {
for (plane = 0; plane < s->planes && !ret; plane++) {
/* level 1 */

1
libavcodec/cfhd.h
View File

@ -114,6 +114,7 @@ typedef struct SubBand {
int width;
int a_height;
int height;
int8_t read_ok;
} SubBand;
typedef struct Plane {