alsdec: check block length

Fix writing over the end

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Addresses: CVE-2013-0845
(cherry picked from commit 2a0fb7286d67c47e44aa76c237ede117b22af616)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 3f7d89034bfe50893927cc92ddcb95a2e9b4178d)
Signed-off-by: Reinhard Tartler <siretart@tauware.de>
This commit is contained in:
Reinhard Tartler 2013-12-08 13:24:26 -05:00
parent ae9652605a
commit d4a24e43ed

View File

@ -1386,6 +1386,11 @@ static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
for (b = 0; b < ctx->num_blocks; b++) {
bd.block_length = div_blocks[b];
if (bd.block_length <= 0) {
av_log(ctx->avctx, AV_LOG_WARNING,
"Invalid block length %d in channel data!\n", bd.block_length);
continue;
}
for (c = 0; c < avctx->channels; c++) {
bd.const_block = ctx->const_block + c;