NFS: remove unneeded check in decode_devicenotify_args()

stable inclusion
from stable-4.19.238
commit 97cc035bdfe754dbfbc2c9b04bc46bc71ef5bc93
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5A6BA
CVE: NA

--------------------------------

[ Upstream commit cb8fac6d ]

[You don't often get email from khoroshilov@ispras.ru. Learn why this is important at http://aka.ms/LearnAboutSenderIdentification.]

Overflow check in not needed anymore after we switch to kmalloc_array().
Signed-off-by: NAlexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: a4f743a6 ("NFSv4.1: Convert open-coded array allocation calls to kmalloc_array()")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

fs/nfs/callback_xdr.c

@@ -281,10 +281,6 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 	n = ntohl(*p++);
 	if (n == 0)
 		goto out;
-	if (n > ULONG_MAX / sizeof(*args->devs)) {
-		status = htonl(NFS4ERR_BADXDR);
-		goto out;
-	}
 
 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 	if (!args->devs) {