hugetlb: fix hugepage leakage

euleros inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5OE36
CVE: NA

------------
Huge page should be released if read_actual_file failed.

---
v2: change pr_info to pr_err_ratelimited

Fixes:1af4fa6d("hugetlb: support private file map")
Signed-off-by: NLiu Zixian <liuzixian4@huawei.com>

mm/hugetlb.c

@@ -4858,8 +4858,12 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 			size_t page_size = huge_page_size(h);
 
 			ret = read_actual_file(page, vma, &off, page_size);
-			if (ret)
+			if (ret) {
+				put_page(page);
+				pr_err_ratelimited("enhanced hugetlb mmap: read file failed\n");
+				ret = vmf_error(ret);
 				goto out;
+			}
 		}
 #endif
 		__SetPageUptodate(page);