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Groups > linux.kernel > #1569188 > unrolled thread
| Started by | John Keeping <john@metanate.com> |
|---|---|
| First post | 2017-01-29 15:10 +0100 |
| Last post | 2017-01-30 19:20 +0100 |
| Articles | 3 — 2 participants |
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[PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf John Keeping <john@metanate.com> - 2017-01-29 15:10 +0100
Re: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf Sean Paul <seanpaul@chromium.org> - 2017-01-30 19:10 +0100
Re: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf John Keeping <john@metanate.com> - 2017-01-30 19:20 +0100
| From | John Keeping <john@metanate.com> |
|---|---|
| Date | 2017-01-29 15:10 +0100 |
| Subject | [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf |
| Message-ID | <t4Yl4-811-19@gated-at.bofh.it> |
As a side-effect of this, encode the endianness explicitly rather than
casting a u16.
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Chris Zhong <zyw@rock-chips.com>
---
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);
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
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| From | Sean Paul <seanpaul@chromium.org> |
|---|---|
| Date | 2017-01-30 19:10 +0100 |
| Subject | Re: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf |
| Message-ID | <t5oyS-7bL-37@gated-at.bofh.it> |
| In reply to | #1569188 |
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 <john@metanate.com>
> Reviewed-by: Chris Zhong <zyw@rock-chips.com>
> ---
> 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
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| From | John Keeping <john@metanate.com> |
|---|---|
| Date | 2017-01-30 19:20 +0100 |
| Subject | Re: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf |
| Message-ID | <t5oIy-7eY-25@gated-at.bofh.it> |
| In reply to | #1569974 |
On Mon, 30 Jan 2017 13:01:46 -0500, Sean Paul wrote:
> 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 <john@metanate.com>
> > Reviewed-by: Chris Zhong <zyw@rock-chips.com>
> > ---
> > 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.
Won't that mask off the data written by "tx_buf[1] << 8"?
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