2022-01-05 12:13:45

by 赵军奎

[permalink] [raw]
Subject: [PATCH v2] gpu/drm: fix potential memleak in error branch

This patch try to fix potential memleak in error branch.
For example:
nv50_sor_create ->nv50_mstm_new-> drm_dp_mst_topology_mgr_init,
In function drm_dp_mst_topology_mgr_init, there are five error
branches, error branch just return error code, no free called.
And we see that the caller didn`t do the drm_dp_mst_topology_mgr_destroy job.
In this case, this may bring in the risk of memleak issue.

Signed-off-by: Bernard Zhao <[email protected]>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index f3d79eda94bb..f73b180dee73 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -5501,7 +5501,10 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
int max_lane_count, int max_link_rate,
int conn_base_id)
{
- struct drm_dp_mst_topology_state *mst_state;
+ struct drm_dp_mst_topology_state *mst_state = NULL;
+
+ mgr->payloads = NULL;
+ mgr->proposed_vcpis = NULL;

mutex_init(&mgr->lock);
mutex_init(&mgr->qlock);
@@ -5523,7 +5526,7 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
*/
mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
if (mgr->delayed_destroy_wq == NULL)
- return -ENOMEM;
+ goto out;

INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
@@ -5539,18 +5542,18 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
mgr->conn_base_id = conn_base_id;
if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
- return -EINVAL;
+ goto failed;
mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
if (!mgr->payloads)
- return -ENOMEM;
+ goto failed;
mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
if (!mgr->proposed_vcpis)
- return -ENOMEM;
+ goto failed;
set_bit(0, &mgr->payload_mask);

mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
if (mst_state == NULL)
- return -ENOMEM;
+ goto failed;

mst_state->total_avail_slots = 63;
mst_state->start_slot = 1;
@@ -5563,6 +5566,13 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
&drm_dp_mst_topology_state_funcs);

return 0;
+
+failed:
+ kfree(mgr->proposed_vcpis);
+ kfree(mgr->payloads);
+ destroy_workqueue(mgr->delayed_destroy_wq);
+out:
+ return -ENOMEM;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);

--
2.33.1