From 665f775bf52fe4d50bacc20bbee77cc568718ad7 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Fri, 8 Nov 2019 14:38:14 +0000
Subject: drm/amd/display: fix dereference of pointer aconnector when it is
Git-commit: 320f6d81aaeed354f832a46685d5eac91006db72
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
null
Currently pointer aconnector is being dereferenced by the call to
to_dm_connector_state before it is being null checked, this could
lead to a null pointer dereference. Fix this by checking that
aconnector is null before dereferencing it.
Addresses-Coverity: ("Dereference before null check")
Reviewed-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 4882b47e85ef..57a226c0bc4a 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -193,12 +193,11 @@ bool dm_helpers_dp_mst_write_payload_allocation_table(
* that blocks before commit guaranteeing that the state
* is not gonna be swapped while still in use in commit tail */
- dm_conn_state = to_dm_connector_state(aconnector->base.state);
-
-
if (!aconnector || !aconnector->mst_port)
return false;
+ dm_conn_state = to_dm_connector_state(aconnector->base.state);
+
mst_mgr = &aconnector->mst_port->mst_mgr;
if (!mst_mgr->mst_state)
--
2.28.0