From:   Qing Wang <wangqing@vivo.com>
To:     Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Wang Qing <wangqing@vivo.com>
Subject: [PATCH] fs: xattr: use vmemdup_user instead of kvmalloc and copy_from_user
Date:   Tue, 14 Dec 2021 04:19:17 -0800
Message-Id: <1639484357-76013-1-git-send-email-wangqing@vivo.com>
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?uwaDWZIvK1ysk2CVZ1W5lerkuUKRTAQSvHY5kauuxJhVwriyJPD1Qip/tdAK?=
 =?us-ascii?Q?JMgWnvgq0DIJkc8mgkarQZeC4IUAXuFJefX4oAZ/vIEgIQcAGCLewd2Mu+Cw?=
 =?us-ascii?Q?/fcVn97pT/OEw2orcNun++RaHPU+zZMPRK4dcs+ySvVXrE0o/g5aokWoJ10T?=
 =?us-ascii?Q?DP6+VoOkihK/D/fK1Hqx/x0wO5cQRDSNEAj/RAuzd7Me4k3pBhz6LHngKjTG?=
 =?us-ascii?Q?Gx2ra6LNA5MFrt51maEt1rA2KTOl0K+aYS6iT605JiLcrkuflgeQ7PTuT5C0?=
 =?us-ascii?Q?2alB6VyIdmbxlpegpdys0vtYvFaSJ5N4CrIsoXjOuU+GVnG6c3xhb9AeT+NW?=
 =?us-ascii?Q?PXoUbXRSK/Y7g/sOG3wvn1MYMciD7nQBVX1ZP6ou1JoQt+HyPudvxEKmEpVA?=
 =?us-ascii?Q?2MtbirAUkwlDdg5/pqdu96qCdL7ifvg2E9JS0gefgOs052xrBe6EFU+pg9V/?=
 =?us-ascii?Q?6azKJvB23/7eiP8BISbQJWSHoyNamznJ8w/BTLnjCcjAfXOJEfzHxUxCoj9+?=
 =?us-ascii?Q?Ld0fPFubLx4gi1XFn12pXdPoufao5AWuxzxB7PJPhbPoldUUtfu2/yqLZtWM?=
 =?us-ascii?Q?Y4II2anzReiz1jKr4jl3oDxnHXPAqj4aQ79MOtrQOur7imhcBYab43rouXsX?=
 =?us-ascii?Q?+hFlFwlyEP3IMGO7ske10QvfOwR53nR9p2I0o3bbCXT76I93Ec3p5uHRR7Sy?=
 =?us-ascii?Q?niRmSfSW9cGX968JLkvwhE4tOR/lrPk5GTh6i/Ca4JxahZ4DYtvvxQISg4Z7?=
 =?us-ascii?Q?VIvdRRkptgxezazOTiujEoMA3DkHeXa+ZI5M7u2yDJFuIU2U7TbD8GTRtqfb?=
 =?us-ascii?Q?aNvjarJuYRD83fG4PTZTqDjWsZ6sr7lc/VTMhgqcsHGYmhWD7l7AAom7xvD1?=
 =?us-ascii?Q?PAtOsGsv0FBVKKB/cDBWOpKkMX8/RZ/S3pKttRCeDIieFmqWjksJspXVxhPZ?=
 =?us-ascii?Q?PMugT8Cv1mtuZt+V1lH1GtNgUinIxcYFiB+sUN8Jgzo75QuqrtTUgsVt9pjm?=
 =?us-ascii?Q?YC01DkwzJ4Kcx1F60PLpzeBGKOAsabXXUd/mDRHTsJeZ8zb3V7ForJ2SSs+r?=
 =?us-ascii?Q?IpYjqhDER6PzBP4TewcvMLjGatLkHGvP34XbeHJJgPOnFAuLTxBD8Le5Afrd?=
 =?us-ascii?Q?s8CgduyDqUX+KRzwrMaUHkKOk96cShealcMrEippFdi8uBIYPNEBNjG34PTM?=
 =?us-ascii?Q?I8BCLKD4hhT72OsRtKpIt/lE26NcLckMvEXL13gPQi/AN9t3WGwqomGzaLQ6?=
 =?us-ascii?Q?4Q+7Nq3Pb6JpY/B+8SbTe/1hDU2Um+UVJX8yh/F6Qovf2+VCzuXbO5IbwNIR?=
 =?us-ascii?Q?q0rQbMHTaivEXvYbFZZLQNK1gKVVIVBtp/KVqsgcLgrcW6DRpMCKCCgZ5H7h?=
 =?us-ascii?Q?nixWkdw1TUbMLV6S2mvQiyTFgaFIm5yGIUaf5SEVGt6xqPtUVYuJnUQgZLC1?=
 =?us-ascii?Q?FvGENtS2OqQ+dZP9cgGuUqU6u2EiapzNuyGhnllq1MQV7QiwURusyS6yubEU?=
 =?us-ascii?Q?UWqAG6SSTYWlrGBYSX8hsyYa5V7TGIhFG9Z/REXQlmdOqaT5nCCy1S+eKoXv?=
 =?us-ascii?Q?tpQq8IoR/ZIdYErOZIUBcldqmdnbeY4cM3eCUDHepN0PCucrYrWLqaVyt4RF?=
 =?us-ascii?Q?TWMBhfmQhEO4vYCU1vReh8A=3D?=
X-OriginatorOrg: vivo.com
X-MS-Exchange-CrossTenant-Network-Message-Id: dff82dbc-4585-4ea4-10a0-08d9befbf7b5
X-MS-Exchange-CrossTenant-AuthSource: SL2PR06MB3082.apcprd06.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Dec 2021 12:19:25.3472
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 923e42dc-48d5-4cbe-b582-1a797a6412ed
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 3zBf9UX32GLnsdaOTCo0H2WEuvtJXWgtkOPyCDi+9OmsfjikBrKhzNLRRQITDiyhCdZm6Hyfuwx8JmIrxeRL0A==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SL2PR06MB3084
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Wang Qing <wangqing@vivo.com>

fix memdup_user.cocci warning:
fs/xattr.c:563:11-19: WARNING opportunity for vmemdup_user

Signed-off-by: Wang Qing <wangqing@vivo.com>
---
 fs/xattr.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/fs/xattr.c b/fs/xattr.c
index 5c8c517..71c301d
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -560,11 +560,9 @@ setxattr(struct user_namespace *mnt_userns, struct dentry *d,
 	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)) {
+			error = PTR_ERR(kvalue);
 			goto out;
 		}
 		if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
-- 
2.7.4