drm/nouveau/vm: fix memory corruption when pgt allocation fails

If we return freed vm, nouveau_drm_open will happily call nouveau_cli_destroy,
which will try to free it again.

Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/core/subdev/vm/base.c b/drivers/gpu/drm/nouveau/core/subdev/vm/base.c
index 082c11b..77c67fc 100644 (file)
--- a/drivers/gpu/drm/nouveau/core/subdev/vm/base.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/vm/base.c
@@ -352,7 +352,7 @@ nouveau_vm_create(struct nouveau_vmmgr *vmm, u64 offset, u64 length,
        u64 mm_length = (offset + length) - mm_offset;
        int ret;
 
-       vm = *pvm = kzalloc(sizeof(*vm), GFP_KERNEL);
+       vm = kzalloc(sizeof(*vm), GFP_KERNEL);
        if (!vm)
                return -ENOMEM;
 
@@ -376,6 +376,8 @@ nouveau_vm_create(struct nouveau_vmmgr *vmm, u64 offset, u64 length,
                return ret;
        }
 
+       *pvm = vm;
+
        return 0;
 }