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avcodec/mpeg4videodec: Use 64 bit intermediates for sprite delta

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Fixes: runtime error: signed integer overflow: -104713 * 65536 cannot be represented in type 'int'
Fixes: 3453/clusterfuzz-testcase-minimized-5555554657239040
Fixes: 3528/clusterfuzz-testcase-minimized-6283628420005888

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 2017-10-08 21:41:54 +02:00
parent f280575a0f
commit e38f280fec
1 changed files with 40 additions and 39 deletions
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79
libavcodec/mpeg4videodec.c
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@ -179,6 +179,7 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
int sprite_ref[4][2];
int virtual_ref[2][2];
int64_t sprite_offset[2][2];
int64_t sprite_delta[2][2];
// only true for rectangle shapes
const int vop_ref[4][2] = { { 0, 0 }, { s->width, 0 },
@ -262,10 +263,10 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
sprite_offset[0][1] =
sprite_offset[1][0] =
sprite_offset[1][1] = 0;
s->sprite_delta[0][0] = a;
s->sprite_delta[0][1] =
s->sprite_delta[1][0] = 0;
s->sprite_delta[1][1] = a;
sprite_delta[0][0] = a;
sprite_delta[0][1] =
sprite_delta[1][0] = 0;
sprite_delta[1][1] = a;
ctx->sprite_shift[0] =
ctx->sprite_shift[1] = 0;
break;
@ -276,10 +277,10 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
a * (vop_ref[0][0] / 2);
sprite_offset[1][1] = ((sprite_ref[0][1] >> 1) | (sprite_ref[0][1] & 1)) -
a * (vop_ref[0][1] / 2);
s->sprite_delta[0][0] = a;
s->sprite_delta[0][1] =
s->sprite_delta[1][0] = 0;
s->sprite_delta[1][1] = a;
sprite_delta[0][0] = a;
sprite_delta[0][1] =
sprite_delta[1][0] = 0;
sprite_delta[1][1] = a;
ctx->sprite_shift[0] =
ctx->sprite_shift[1] = 0;
break;
@ -304,10 +305,10 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) *
((int64_t)-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
(int64_t) sprite_ref[0][1] - 16 * w2 + (1 << (alpha + rho + 1)));
s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
s->sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
s->sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
ctx->sprite_shift[0] = alpha + rho;
ctx->sprite_shift[1] = alpha + rho + 2;
@ -332,28 +333,28 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
((int64_t)-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3 * (-2 * vop_ref[0][1] + 1) +
(int64_t)2 * w2 * h3 * r * sprite_ref[0][1] - 16 * w2 * h3 +
((int64_t)1 << (alpha + beta + rho - min_ab + 1));
s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3;
s->sprite_delta[0][1] = (-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3;
s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3;
s->sprite_delta[1][1] = (-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3;
sprite_delta[0][0] = (-r * (int64_t)sprite_ref[0][0] + virtual_ref[0][0]) * h3;
sprite_delta[0][1] = (-r * (int64_t)sprite_ref[0][0] + virtual_ref[1][0]) * w3;
sprite_delta[1][0] = (-r * (int64_t)sprite_ref[0][1] + virtual_ref[0][1]) * h3;
sprite_delta[1][1] = (-r * (int64_t)sprite_ref[0][1] + virtual_ref[1][1]) * w3;
ctx->sprite_shift[0] = alpha + beta + rho - min_ab;
ctx->sprite_shift[1] = alpha + beta + rho - min_ab + 2;
break;
}
/* try to simplify the situation */
if (s->sprite_delta[0][0] == a << ctx->sprite_shift[0] &&
s->sprite_delta[0][1] == 0 &&
s->sprite_delta[1][0] == 0 &&
s->sprite_delta[1][1] == a << ctx->sprite_shift[0]) {
if (sprite_delta[0][0] == a << ctx->sprite_shift[0] &&
sprite_delta[0][1] == 0 &&
sprite_delta[1][0] == 0 &&
sprite_delta[1][1] == a << ctx->sprite_shift[0]) {
sprite_offset[0][0] >>= ctx->sprite_shift[0];
sprite_offset[0][1] >>= ctx->sprite_shift[0];
sprite_offset[1][0] >>= ctx->sprite_shift[1];
sprite_offset[1][1] >>= ctx->sprite_shift[1];
s->sprite_delta[0][0] = a;
s->sprite_delta[0][1] = 0;
s->sprite_delta[1][0] = 0;
s->sprite_delta[1][1] = a;
sprite_delta[0][0] = a;
sprite_delta[0][1] = 0;
sprite_delta[1][0] = 0;
sprite_delta[1][1] = a;
ctx->sprite_shift[0] = 0;
ctx->sprite_shift[1] = 0;
s->real_sprite_warping_points = 1;
@ -365,8 +366,8 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
if (shift_c < 0 || shift_y < 0 ||
FFABS( sprite_offset[0][i]) >= INT_MAX >> shift_y ||
FFABS( sprite_offset[1][i]) >= INT_MAX >> shift_c ||
FFABS(s->sprite_delta[0][i]) >= INT_MAX >> shift_y ||
FFABS(s->sprite_delta[1][i]) >= INT_MAX >> shift_y
FFABS( sprite_delta[0][i]) >= INT_MAX >> shift_y ||
FFABS( sprite_delta[1][i]) >= INT_MAX >> shift_y
) {
avpriv_request_sample(s->avctx, "Too large sprite shift, delta or offset");
goto overflow;
@ -376,22 +377,22 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
for (i = 0; i < 2; i++) {
sprite_offset[0][i] *= 1 << shift_y;
sprite_offset[1][i] *= 1 << shift_c;
s->sprite_delta[0][i] *= 1 << shift_y;
s->sprite_delta[1][i] *= 1 << shift_y;
sprite_delta[0][i] *= 1 << shift_y;
sprite_delta[1][i] *= 1 << shift_y;
ctx->sprite_shift[i] = 16;
}
for (i = 0; i < 2; i++) {
int64_t sd[2] = {
s->sprite_delta[i][0] - a * (1LL<<16),
s->sprite_delta[i][1] - a * (1LL<<16)
sprite_delta[i][0] - a * (1LL<<16),
sprite_delta[i][1] - a * (1LL<<16)
};
if (llabs(sprite_offset[0][i] + s->sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
llabs(sprite_offset[0][i] + s->sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
llabs(sprite_offset[0][i] + s->sprite_delta[i][0] * (w+16LL) + s->sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
llabs(s->sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
llabs(s->sprite_delta[i][1] * (w+16LL)) >= INT_MAX ||
if (llabs(sprite_offset[0][i] + sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
llabs(sprite_offset[0][i] + sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
llabs(sprite_offset[0][i] + sprite_delta[i][0] * (w+16LL) + sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
llabs(sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
llabs(sprite_delta[i][1] * (w+16LL)) >= INT_MAX ||
llabs(sd[0]) >= INT_MAX ||
llabs(sd[1]) >= INT_MAX ||
llabs(sprite_offset[0][i] + sd[0] * (w+16LL)) >= INT_MAX ||
@ -405,10 +406,10 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
s->real_sprite_warping_points = ctx->num_sprite_warping_points;
}
s->sprite_offset[0][0] = sprite_offset[0][0];
s->sprite_offset[0][1] = sprite_offset[0][1];
s->sprite_offset[1][0] = sprite_offset[1][0];
s->sprite_offset[1][1] = sprite_offset[1][1];
for (i = 0; i < 4; i++) {
s->sprite_offset[i&1][i>>1] = sprite_offset[i&1][i>>1];
s->sprite_delta [i&1][i>>1] = sprite_delta [i&1][i>>1];
}
return 0;
overflow: