[PATCH V1] accel/amdxdna: Fix leak when pinning ubuf pages

[Lizhi Hou <lizhi.hou@amd.com>]

From: Max Zhen <max.zhen@amd.com>

When pin_user_pages_fast() returns fewer pages than requested, the pages
that were successfully pinned are not released, leading to a leak.

Fix this by unpinning any partially pinned pages before returning failure.

Fixes: bd72d4acda10 ("accel/amdxdna: Support user space allocated buffer")
Signed-off-by: Max Zhen <max.zhen@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
---
 drivers/accel/amdxdna/amdxdna_ubuf.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/accel/amdxdna/amdxdna_ubuf.c b/drivers/accel/amdxdna/amdxdna_ubuf.c
index fb999aa25318..4c0647057759 100644
--- a/drivers/accel/amdxdna/amdxdna_ubuf.c
+++ b/drivers/accel/amdxdna/amdxdna_ubuf.c
@@ -196,13 +196,17 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev,
 		ret = pin_user_pages_fast(va_ent[i].vaddr, npages,
 					  FOLL_WRITE | FOLL_LONGTERM,
 					  &ubuf->pages[start]);
-		if (ret < 0 || ret != npages) {
-			ret = -ENOMEM;
+		if (ret >= 0) {
+			start += ret;
+			if (ret != npages) {
+				XDNA_ERR(xdna, "Partially pinned pages %d/%u", ret, npages);
+				ret = -ENOMEM;
+				goto destroy_pages;
+			}
+		} else {
 			XDNA_ERR(xdna, "Failed to pin pages ret %d", ret);
 			goto destroy_pages;
 		}
-
-		start += ret;
 	}
 
 	exp_info.ops = &amdxdna_ubuf_dmabuf_ops;
-- 
2.34.1