[PATCH v2] drm/mediatek: Fix potential memory leak if vmap() fail

[Sui Jingfeng]

Also return -ENOMEM if such a failure happens, the implement should take
responsibility for the error handling.

Fixes: 3df64d7b0a4f ("drm/mediatek: Implement gem prime vmap/vunmap function")
Reviewed-by: Matthias Brugger <matthias.bgg at gmail.com>
Reviewed-by: Alexandre Mergnat <amergnat at baylibre.com>
Signed-off-by: Sui Jingfeng <suijingfeng at loongson.cn>
---
 drivers/gpu/drm/mediatek/mtk_drm_gem.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index a25b28d3ee90..9f364df52478 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -247,7 +247,11 @@ int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
 
 	mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
 			       pgprot_writecombine(PAGE_KERNEL));
-
+	if (!mtk_gem->kvaddr) {
+		kfree(sgt);
+		kfree(mtk_gem->pages);
+		return -ENOMEM;
+	}
 out:
 	kfree(sgt);
 	iosys_map_set_vaddr(map, mtk_gem->kvaddr);
-- 
2.34.1