[PATCH 5.3 135/197] drm/amdgpu: user pages array memory leak fix

[Greg Kroah-Hartman]

From: Philip Yang <Philip.Yang@xxxxxxx>

commit 209620b422945ee03cebb03f726e706d537b692d upstream.

user_pages array should always be freed after validation regardless if
user pages are changed after bo is created because with HMM change parse
bo always allocate user pages array to get user pages for userptr bo.

v2: remove unused local variable and amend commit

v3: add back get user pages in gem_userptr_ioctl, to detect application
bug where an userptr VMA is not ananymous memory and reject it.

Bugzilla: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1844962

Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
Tested-by: Joe Barnett <thejoe@xxxxxxxxx>
Reviewed-by: Christian KÃnig <christian.koenig@xxxxxxx>
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 5.3
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -536,7 +536,6 @@ static int amdgpu_cs_list_validate(struc
 
 	list_for_each_entry(lobj, validated, tv.head) {
 		struct amdgpu_bo *bo = ttm_to_amdgpu_bo(lobj->tv.bo);
-		bool binding_userptr = false;
 		struct mm_struct *usermm;
 
 		usermm = amdgpu_ttm_tt_get_usermm(bo->tbo.ttm);
@@ -553,7 +552,6 @@ static int amdgpu_cs_list_validate(struc
 
 			amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm,
 						     lobj->user_pages);
-			binding_userptr = true;
 		}
 
 		if (p->evictable == lobj)
@@ -563,10 +561,8 @@ static int amdgpu_cs_list_validate(struc
 		if (r)
 			return r;
 
-		if (binding_userptr) {
-			kvfree(lobj->user_pages);
-			lobj->user_pages = NULL;
-		}
+		kvfree(lobj->user_pages);
+		lobj->user_pages = NULL;
 	}
 	return 0;
 }