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avcodec/jpeg2000: check if decoding will exceed internal precision #107

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avcodec/jpeg2000: check if decoding will exceed internal precision #107

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32 changes: 31 additions & 1 deletion libavcodec/jpeg2000htdec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -572,6 +572,14 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s,

const uint8_t *vlc_buf = Dcup + Pcup;

/*
* Bound on the recision needed to process the codeblock. The number of
* decoded bit planes is equal to at most cblk->zbp + 2 since S_blk = P if
* there are no placeholder passes or HT Sets and P = cblk->zbp. See Rec.
* ITU-T T.814, 7.6.
*/
int maxbp = cblk->zbp + 2;

/* convert to raster-scan */
const uint16_t is_border_x = width % 2;
const uint16_t is_border_y = height % 2;
Expand All @@ -590,6 +598,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s,
goto free;
}

/* do we have enough precision, assuming a 32-bit decoding path */
if (maxbp >= 32)
return AVERROR_INVALIDDATA;

sigma = sigma_n;
mu = mu_n;

Expand Down Expand Up @@ -676,6 +688,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s,
}
U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
U[J2K_Q2] = kappa[J2K_Q2] + u[J2K_Q2];
if (U[J2K_Q1] > maxbp || U[J2K_Q2] > maxbp) {
ret = AVERROR_INVALIDDATA;
goto free;
}

for (int i = 0; i < 4; i++) {
m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
Expand Down Expand Up @@ -713,6 +729,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s,
}

U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
if (U[J2K_Q1] > maxbp) {
ret = AVERROR_INVALIDDATA;
goto free;
}

for (int i = 0; i < 4; i++)
m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
Expand Down Expand Up @@ -842,6 +862,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s,

U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
U[J2K_Q2] = kappa[J2K_Q2] + u[J2K_Q2];
if (U[J2K_Q1] > maxbp || U[J2K_Q2] > maxbp) {
ret = AVERROR_INVALIDDATA;
goto free;
}

for (int i = 0; i < 4; i++) {
m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
Expand Down Expand Up @@ -910,6 +934,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s,
kappa[J2K_Q1] = FFMAX(1, gamma[J2K_Q1] * (max_e[J2K_Q1] - 1));

U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
if (U[J2K_Q1] > maxbp) {
ret = AVERROR_INVALIDDATA;
goto free;
}

for (int i = 0; i < 4; i++)
m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
Expand Down Expand Up @@ -1238,8 +1266,10 @@ ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c
}
if ((ret = jpeg2000_decode_ht_cleanup_segment(s, cblk, t1, &mel_state, &mel, &vlc,
&mag_sgn, Dcup, Lcup, Pcup, pLSB, width,
height, sample_buf, block_states)) < 0)
height, sample_buf, block_states)) < 0) {
av_log(s->avctx, AV_LOG_ERROR, "Bad HT cleanup segment\n");
goto free;
}

if (cblk->npasses > 1)
jpeg2000_decode_sigprop_segment(cblk, width, height, Dref, Lref,
Expand Down