io_uring/zcrx: fix leaking pages on sg init fail

If sg_alloc_table_from_pages() fails, io_import_umem() returns without
cleaning up pinned pages first. Fix it.

Fixes: b84621d ("io_uring/zcrx: allocate sgtable for umem areas")
Signed-off-by: Pavel Begunkov <[email protected]>
Link: https://lore.kernel.org/r/9fd94d1bc8c316611eccfec7579799182ff3fb0a.1753091564.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <[email protected]>

Author: isilence

io_uring/zcrx.c

@@ -194,8 +194,10 @@ static int io_import_umem(struct io_zcrx_ifq *ifq,
 	ret = sg_alloc_table_from_pages(&mem->page_sg_table, pages, nr_pages,
 					0, nr_pages << PAGE_SHIFT,
 					GFP_KERNEL_ACCOUNT);
-	if (ret)
+	if (ret) {
+		unpin_user_pages(pages, nr_pages);
 		return ret;
+	}
 
 	mem->account_pages = io_count_account_pages(pages, nr_pages);
 	ret = io_account_mem(ifq->ctx, mem->account_pages);