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 <mich...@niedermayer.cc> --- libavcodec/cfhd.c | 20 ++++++++++++++++++++ libavcodec/cfhd.h | 1 + 2 files changed, 21 insertions(+) diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c index 8bf910cde6..61e02999e9 100644 --- a/libavcodec/cfhd.c +++ b/libavcodec/cfhd.c @@ -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 +929,16 @@ finish: goto end; } + for (plane = 0; plane < s->planes; plane++) { + int o; + for (o = 0; o < 4 ; o++) { + if (!s->plane[plane].band[0][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 */ diff --git a/libavcodec/cfhd.h b/libavcodec/cfhd.h index 4ec2a2ce8b..19e5c7cf03 100644 --- a/libavcodec/cfhd.h +++ b/libavcodec/cfhd.h @@ -114,6 +114,7 @@ typedef struct SubBand { int width; int a_height; int height; + int8_t read_ok; } SubBand; typedef struct Plane { -- 2.17.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
