diff options
| author | Dave Airlie <airlied@gmail.com> | 2015-10-14 18:51:17 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-27 09:51:57 +0900 |
| commit | 510035b39ccbbbc0e5d9018796d60c009c3becba (patch) | |
| tree | 55864245206b948192e95a5399d3ff91d6741204 | |
| parent | db531487d7f87820533fa37be4e52439034075d1 (diff) | |
drm/dp/mst: make mst i2c transfer code more robust.
commit ae491542cbbbcca0ec8938c37d4079a985e58440 upstream.
This zeroes the msg so no random stack data ends up getting
sent, it also limits the function to not accepting > 4
i2c msgs.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 3 | ||||
| -rw-r--r-- | 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 7f467fdc9107..2a2eb96caeda 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2766,12 +2766,13 @@ 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 86d0b25ed054..a89f505c856b 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; }; |