drm/amdgpu: user pages array memory leak fix

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@amd.com>
Tested-by: Joe Barnett <thejoe@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org # 5.3
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 8b26c970a3cb1f364c1595c8a394daf44420d74d..90df22081a252b7e44e1bf6b539c2dacc2920dec 100644 (file)
--- 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(struct amdgpu_cs_parser *p,
 
        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(struct amdgpu_cs_parser *p,
 
                        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(struct amdgpu_cs_parser *p,
                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;
 }