From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753860AbdA3SBu (ORCPT ); Mon, 30 Jan 2017 13:01:50 -0500 Received: from mail-qt0-f180.google.com ([209.85.216.180]:32776 "EHLO mail-qt0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154AbdA3SBt (ORCPT ); Mon, 30 Jan 2017 13:01:49 -0500 Date: Mon, 30 Jan 2017 13:01:46 -0500 From: Sean Paul To: John Keeping Cc: Mark Yao , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, Chris Zhong , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf Message-ID: <20170130180146.GG20076@art_vandelay> References: <20170129132444.25251-1-john@metanate.com> <20170129132444.25251-7-john@metanate.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170129132444.25251-7-john@metanate.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 29, 2017 at 01:24:26PM +0000, John Keeping wrote: > As a side-effect of this, encode the endianness explicitly rather than > casting a u16. > > Signed-off-by: John Keeping > Reviewed-by: Chris Zhong > --- > v3: > - Add Chris' Reviewed-by > Unchanged in v2 > > drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 9 +++++++-- > 1 file changed, 7 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..2e6ad4591ebf 100644 > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > @@ -572,8 +572,13 @@ 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; > + u32 val = GEN_HTYPE(msg->type); > + > + if (msg->tx_len > 0) > + val |= GEN_HDATA(tx_buf[0]); > + if (msg->tx_len > 1) > + val |= GEN_HDATA(tx_buf[1] << 8); You should probably update the mask inside GEN_HDATA to mask off 8 bits instead of 16. Sean > > if (msg->tx_len > 2) { > dev_err(dsi->dev, "too long tx buf length %zu for short write\n", > -- > 2.11.0.197.gb556de5.dirty > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Sean Paul, Software Engineer, Google / Chromium OS