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authorJosé Roberto de Souza <jose.souza@intel.com>2020-01-29 15:24:48 -0800
committerLyude Paul <lyude@redhat.com>2020-01-30 16:56:50 -0500
commit8ccb5bf7619c6523e7a4384a84b72e7be804298c (patch)
treef615ee0104a76fb10019df836579d65f248cf88f /drivers/gpu/drm/drm_dp_mst_topology.c
parentcf913e9683273f2640501094fa63a67e29f437b3 (diff)
drm/mst: Fix possible NULL pointer dereference in drm_dp_mst_process_up_req()
According to DP specification, DP_SINK_EVENT_NOTIFY is also a broadcast message but as this function only handles DP_CONNECTION_STATUS_NOTIFY I will only make the static analyzer that caught this issue happy by not calling drm_dp_get_mst_branch_device_by_guid() with a NULL guid, causing drm_dp_mst_process_up_req() to return in the "if (!mstb)" right bellow. Fixes: 9408cc94eb04 ("drm/dp_mst: Handle UP requests asynchronously") Cc: Lyude Paul <lyude@redhat.com> Cc: Sean Paul <sean@poorly.run> Cc: <stable@vger.kernel.org> # v5.5+ Signed-off-by: José Roberto de Souza <jose.souza@intel.com> [added cc to stable] Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200129232448.84704-1-jose.souza@intel.com
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
-rw-r--r--drivers/gpu/drm/drm_dp_mst_topology.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index e6afe4faeca6..105bb5f40166 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3760,7 +3760,8 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
guid = msg->u.resource_stat.guid;
- mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
+ if (guid)
+ mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
} else {
mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
}