netdev - [PATCH] vhost-vdpa: Refactor copy_to_user() usage in vhost_vdpa_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <79b2f48a-f6a1-4bfc-9a8d-cb09777f2a07@web.de>
Date: Wed, 25 Sep 2024 20:48:16 +0200
From: Markus Elfring <Markus.Elfring@....de>
To: virtualization@...ts.linux.dev, kvm@...r.kernel.org,
 netdev@...r.kernel.org, Eugenio Pérez
 <eperezma@...hat.com>, Jason Wang <jasowang@...hat.com>,
 "Michael S. Tsirkin" <mst@...hat.com>, Tiwei Bie <tiwei.bie@...el.com>
Cc: LKML <linux-kernel@...r.kernel.org>, kernel-janitors@...r.kernel.org
Subject: [PATCH] vhost-vdpa: Refactor copy_to_user() usage in
 vhost_vdpa_get_config()

From: Markus Elfring <elfring@...rs.sourceforge.net>
Date: Wed, 25 Sep 2024 20:36:35 +0200

Assign the return value from a copy_to_user() call to an additional
local variable so that a kvfree() call and return statement can be
omitted accordingly.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
---
 drivers/vhost/vdpa.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 5a49b5a6d496..ca69527a822c 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -370,13 +370,11 @@ static long vhost_vdpa_get_config(struct vhost_vdpa *v,

 	vdpa_get_config(vdpa, config.off, buf, config.len);

-	if (copy_to_user(c->buf, buf, config.len)) {
+	{
+		unsigned long ctu = copy_to_user(c->buf, buf, config.len);
 		kvfree(buf);
-		return -EFAULT;
+		return ctu ? -EFAULT : 0;
 	}
-
-	kvfree(buf);
-	return 0;
 }

 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
--
2.46.1