| Message ID | 1444812677-11895-1-git-send-email-airlied@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Oct 14, 2015 at 06:51:17PM +1000, Dave Airlie wrote: > This zeroes the msg so no random stack data ends up getting > sent, it also limits the function to not accepting > 4 > i2c msgs. > > Cc: stable@vger.kernel.org > Signed-off-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > drivers/gpu/drm/drm_dp_mst_topology.c | 3 ++- > include/drm/drm_dp_mst_helper.h | 3 ++- > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c > index bf27a07..5bca390 100644 > --- a/drivers/gpu/drm/drm_dp_mst_topology.c > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c > @@ -2801,12 +2801,13 @@ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs > if (msgs[num - 1].flags & I2C_M_RD) > reading = true; > > - if (!reading) { > + if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) { > DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n"); > ret = -EIO; > goto out; > } > > + memset(&msg, 0, sizeof(msg)); > msg.req_type = DP_REMOTE_I2C_READ; > msg.u.i2c_read.num_transactions = num - 1; > msg.u.i2c_read.port_number = port->port_num; > diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h > index 0f408b0..5340099 100644 > --- a/include/drm/drm_dp_mst_helper.h > +++ b/include/drm/drm_dp_mst_helper.h > @@ -253,6 +253,7 @@ struct drm_dp_remote_dpcd_write { > u8 *bytes; > }; > > +#define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4 > struct drm_dp_remote_i2c_read { > u8 num_transactions; > u8 port_number; > @@ -262,7 +263,7 @@ struct drm_dp_remote_i2c_read { > u8 *bytes; > u8 no_stop_bit; > u8 i2c_transaction_delay; > - } transactions[4]; > + } transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS]; > u8 read_i2c_device_id; > u8 num_bytes_read; > }; > -- > 2.4.3 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index bf27a07..5bca390 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2801,12 +2801,13 @@ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs if (msgs[num - 1].flags & I2C_M_RD) reading = true; - if (!reading) { + if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) { DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n"); ret = -EIO; goto out; } + memset(&msg, 0, sizeof(msg)); msg.req_type = DP_REMOTE_I2C_READ; msg.u.i2c_read.num_transactions = num - 1; msg.u.i2c_read.port_number = port->port_num; diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h index 0f408b0..5340099 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -253,6 +253,7 @@ struct drm_dp_remote_dpcd_write { u8 *bytes; }; +#define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4 struct drm_dp_remote_i2c_read { u8 num_transactions; u8 port_number; @@ -262,7 +263,7 @@ struct drm_dp_remote_i2c_read { u8 *bytes; u8 no_stop_bit; u8 i2c_transaction_delay; - } transactions[4]; + } transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS]; u8 read_i2c_device_id; u8 num_bytes_read; };
This zeroes the msg so no random stack data ends up getting sent, it also limits the function to not accepting > 4 i2c msgs. Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com> --- drivers/gpu/drm/drm_dp_mst_topology.c | 3 ++- include/drm/drm_dp_mst_helper.h | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)