From: John Keeping Date: Fri, 24 Feb 2017 12:54:49 +0000 (+0000) Subject: drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=dad17ed01e81c1d697b98632ea126d95e2a1e8d4;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf As a side-effect of this, encode the endianness explicitly rather than casting a u16. Signed-off-by: John Keeping Signed-off-by: Sean Paul Link: http://patchwork.freedesktop.org/patch/msgid/20170224125506.21533-7-john@metanate.com --- diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c index 4be1ff3a42bb..f55010312f25 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c @@ -572,8 +572,14 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, const struct mipi_dsi_msg *msg) { - const u16 *tx_buf = msg->tx_buf; - u32 val = GEN_HDATA(*tx_buf) | GEN_HTYPE(msg->type); + const u8 *tx_buf = msg->tx_buf; + u16 data = 0; + u32 val; + + if (msg->tx_len > 0) + data |= tx_buf[0]; + if (msg->tx_len > 1) + data |= tx_buf[1] << 8; if (msg->tx_len > 2) { dev_err(dsi->dev, "too long tx buf length %zu for short write\n", @@ -581,6 +587,7 @@ static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, return -EINVAL; } + val = GEN_HDATA(data) | GEN_HTYPE(msg->type); return dw_mipi_dsi_gen_pkt_hdr_write(dsi, val); }