From a864dff48daf5f91abbeabf85e7a6b27a7ed9d37 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Exp=C3=B3sito?= <jose.exposito89@gmail.com>
Date: Sun, 9 Jan 2022 19:42:45 +0100
Subject: drm/amd/display: invalid parameter check in dmub_hpd_callback
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Git-commit: 978ffac878fd64039f95798b15b430032d2d89d5
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
The function performs a check on the "adev" input parameter, however, it
is used before the check.
Initialize the "dev" variable after the sanity check to avoid a possible
NULL pointer dereference.
Fixes: e27c41d5b0681 ("drm/amd/display: Support for DMUB HPD interrupt handling")
Addresses-Coverity-ID: 1493909 ("Null pointer dereference")
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index b7dc98c9f08b..7f9773f8dab6 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -658,7 +658,7 @@ static void dmub_hpd_callback(struct amdgpu_device *adev,
struct drm_connector_list_iter iter;
struct dc_link *link;
uint8_t link_index = 0;
- struct drm_device *dev = adev->dm.ddev;
+ struct drm_device *dev;
if (adev == NULL)
return;
@@ -675,6 +675,7 @@ static void dmub_hpd_callback(struct amdgpu_device *adev,
link_index = notify->link_index;
link = adev->dm.dc->links[link_index];
+ dev = adev->dm.ddev;
drm_connector_list_iter_begin(dev, &iter);
drm_for_each_connector_iter(connector, &iter) {
--
2.38.1