[PATCH] xattr: switch to vmemdup_user()

From: Yang Li <yang.lee@linux.alibaba.com>
To: viro@zeniv.linux.org.uk
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Yang Li <yang.lee@linux.alibaba.com>
Subject: [PATCH] xattr: switch to vmemdup_user()
Date: Tue,  2 Mar 2021 14:32:21 +0800	[thread overview]
Message-ID: <1614666741-16796-1-git-send-email-yang.lee@linux.alibaba.com> (raw)

Replace opencoded alloc and copy with vmemdup_user()

fixed the following coccicheck:
./fs/xattr.c:561:11-19: WARNING opportunity for vmemdup_user

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
---
 fs/xattr.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/xattr.c b/fs/xattr.c
index b3444e0..b947ad2 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -558,11 +558,10 @@ int __vfs_setxattr_noperm(struct user_namespace *mnt_userns,
 	if (size) {
 		if (size > XATTR_SIZE_MAX)
 			return -E2BIG;
-		kvalue = kvmalloc(size, GFP_KERNEL);
-		if (!kvalue)
-			return -ENOMEM;
-		if (copy_from_user(kvalue, value, size)) {
-			error = -EFAULT;
+		kvalue = vmemdup_user(value, size);
+
+		if (IS_ERR(kvalue)) {
+			r = PTR_ERR(kvalue);
 			goto out;
 		}
 		if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
-- 
1.8.3.1

