[PATCH 3/5] drm/amd/display: Fix USB4 hot plug crash issue

[Nicholas Kazlauskas]

From: Jude Shih <shens...@amd.com>

[Why]
Notify data from outbox corrupt, the notify type should be 2 (HPD) instead of 0
(No data). We copied the address instead of the value. The memory might be
freed in the end of outbox IRQ

[How]
We should allocate the memory of notify and copy the whole content from outbox 
to
hpd handle function

Fixes: 5cecad78ea53 ("drm/amd/display: Support for SET_CONFIG processing with 
DMUB")
Signed-off-by: Jude Shih <shens...@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlaus...@amd.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 23 +++++++++++++------
 1 file changed, 16 insertions(+), 7 deletions(-)

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 4cd64529b180..0ad6d0e2a2d8 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -730,6 +730,8 @@ static void dm_handle_hpd_work(struct work_struct *work)
                
dmub_hpd_wrk->adev->dm.dmub_callback[dmub_hpd_wrk->dmub_notify->type](dmub_hpd_wrk->adev,
                dmub_hpd_wrk->dmub_notify);
        }
+
+       kfree(dmub_hpd_wrk->dmub_notify);
        kfree(dmub_hpd_wrk);
 
 }
@@ -755,12 +757,6 @@ static void dm_dmub_outbox1_low_irq(void *interrupt_params)
 
        if (dc_enable_dmub_notifications(adev->dm.dc) &&
                irq_params->irq_src == DC_IRQ_SOURCE_DMCUB_OUTBOX) {
-               dmub_hpd_wrk = kzalloc(sizeof(*dmub_hpd_wrk), GFP_ATOMIC);
-               if (!dmub_hpd_wrk) {
-                       DRM_ERROR("Failed to allocate dmub_hpd_wrk");
-                       return;
-               }
-               INIT_WORK(&dmub_hpd_wrk->handle_hpd_work, dm_handle_hpd_work);
 
                do {
                        dc_stat_get_dmub_notification(adev->dm.dc, &notify);
@@ -769,7 +765,20 @@ static void dm_dmub_outbox1_low_irq(void *interrupt_params)
                                continue;
                        }
                        if (dm->dmub_thread_offload[notify.type] == true) {
-                               dmub_hpd_wrk->dmub_notify = &notify;
+                               dmub_hpd_wrk = kzalloc(sizeof(*dmub_hpd_wrk), 
GFP_ATOMIC);
+                               if (!dmub_hpd_wrk) {
+                                       DRM_ERROR("Failed to allocate 
dmub_hpd_wrk");
+                                       return;
+                               }
+                               dmub_hpd_wrk->dmub_notify = 
kzalloc(sizeof(struct dmub_notification), GFP_ATOMIC);
+                               if (!dmub_hpd_wrk->dmub_notify) {
+                                       kfree(dmub_hpd_wrk);
+                                       DRM_ERROR("Failed to allocate 
dmub_hpd_wrk->dmub_notify");
+                                       return;
+                               }
+                               INIT_WORK(&dmub_hpd_wrk->handle_hpd_work, 
dm_handle_hpd_work);
+                               if (dmub_hpd_wrk->dmub_notify)
+                                       memcpy(dmub_hpd_wrk->dmub_notify, 
&notify, sizeof(struct dmub_notification));
                                dmub_hpd_wrk->adev = adev;
                                if (notify.type == DMUB_NOTIFICATION_HPD) {
                                        plink = 
adev->dm.dc->links[notify.link_index];
-- 
2.25.1