From 30730c7f5943b3beace1e29f7f1476e05de3da14 Mon Sep 17 00:00:00 2001 From: Adam Richter Date: Fri, 16 Oct 2015 03:33:02 -0700 Subject: [PATCH] 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(-) 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; } -- 2.20.1