From mboxrd@z Thu Jan 1 00:00:00 1970 From: john@metanate.com (John Keeping) Date: Fri, 24 Feb 2017 12:54:49 +0000 Subject: [PATCH v4 06/23] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf In-Reply-To: <20170224125506.21533-1-john@metanate.com> References: <20170224125506.21533-1-john@metanate.com> Message-ID: <20170224125506.21533-7-john@metanate.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org As a side-effect of this, encode the endianness explicitly rather than casting a u16. Signed-off-by: John Keeping --- v4: - Introduce "data" variable to avoid confusion around the masking in GEN_HDATA() v3: - Add Chris' Reviewed-by Unchanged in v2 --- drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) 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); } -- 2.12.0.rc0.230.gf625d4cdb9.dirty