From ae491542cbbbcca0ec8938c37d4079a985e58440 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Wed, 14 Oct 2015 18:51:17 +1000 Subject: drm/dp/mst: make mst i2c transfer code more robust. 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 Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_dp_mst_topology.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c') diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index bf27a07dbce3..5bca390d9ae2 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; -- cgit v1.2.3 From 30730c7f5943b3beace1e29f7f1476e05de3da14 Mon Sep 17 00:00:00 2001 From: Adam Richter Date: Fri, 16 Oct 2015 03:33:02 -0700 Subject: drm: fix mutex leak in drm_dp_get_mst_branch_device In Linux 4.3-rc5, there is an error case in drm_dp_get_branch_device that returns without releasing mgr->lock, resulting a spew of kernel messages about a kernel work function possibly having leaked a mutex and presumably more serious adverse consequences later. This patch changes the error to "goto out" to unlock the mutex before returning. [airlied: grabbed from drm-next as it fixes something we've seen] Signed-off-by: Adam J. Richter Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_dp_mst_topology.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c') diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 5bca390d9ae2..809959d56d78 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1194,17 +1194,18 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_ list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) { - if (!port->mstb) { + mstb = port->mstb; + if (!mstb) { DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]); - return NULL; + goto out; } - mstb = port->mstb; break; } } } kref_get(&mstb->kref); +out: mutex_unlock(&mgr->lock); return mstb; } -- cgit v1.2.3