png: check bit depth for PAL8/Y400A pixel formats.

Wrong bit depth can lead to invalid rowsize values, which crashes the
decoder further down.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit d2205d6543881f2e6fa18c8a354bbcf91a1235f7)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit b8d6ba9d50e80fdce2ed74cdaffd4960df8a21c5)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 33f93005f1a86c108302b4c5978aa1a3d8e092cc)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
This commit is contained in:
Ronald S. Bultje 2012-05-02 10:58:55 -07:00 committed by Reinhard Tartler
parent 97ed486fff
commit e17b1536a1

View File

@ -487,9 +487,11 @@ static int decode_frame(AVCodecContext *avctx,
} else if (s->bit_depth == 1 &&
s->color_type == PNG_COLOR_TYPE_GRAY) {
avctx->pix_fmt = PIX_FMT_MONOBLACK;
} else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_PALETTE) {
avctx->pix_fmt = PIX_FMT_PAL8;
} else if (s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
avctx->pix_fmt = PIX_FMT_Y400A;
} else {
goto fail;