virtualization.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
	Tiwei Bie <tiwei.bie@intel.com>,
	Xie Yongji <xieyongji@bytedance.com>
Cc: "Eugenio Pérez" <eperezma@redhat.com>,
	kernel-janitors@vger.kernel.org, kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org
Subject: [PATCH 2/2 v4] vdpa: check that offsets are within bounds
Date: Wed, 8 Dec 2021 13:33:37 +0300	[thread overview]
Message-ID: <20211208103337.GA4047@kili> (raw)
In-Reply-To: <20211208103307.GA3778@kili>

In this function "c->off" is a u32 and "size" is a long.  On 64bit systems
if "c->off" is greater than "size" then "size - c->off" is a negative and
we always return -E2BIG.  But on 32bit systems the subtraction is type
promoted to a high positive u32 value and basically any "c->len" is
accepted.

Fixes: 4c8cf31885f6 ("vhost: introduce vDPA-based backend")
Reported-by: Xie Yongji <xieyongji@bytedance.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v4: split into a separate patch

 drivers/vhost/vdpa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 29cced1cd277..e3c4f059b21a 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -197,7 +197,7 @@ static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
 	struct vdpa_device *vdpa = v->vdpa;
 	long size = vdpa->config->get_config_size(vdpa);
 
-	if (c->len == 0)
+	if (c->len == 0 || c->off > size)
 		return -EINVAL;
 
 	if (c->len > size - c->off)
-- 
2.20.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

  reply	other threads:[~2021-12-08 10:34 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-08 10:33 [PATCH 1/2 v4] vduse: fix memory corruption in vduse_dev_ioctl() Dan Carpenter
2021-12-08 10:33 ` Dan Carpenter [this message]
2021-12-09  2:12   ` [PATCH 2/2 v4] vdpa: check that offsets are within bounds Jason Wang
2021-12-09  2:12 ` [PATCH 1/2 v4] vduse: fix memory corruption in vduse_dev_ioctl() Jason Wang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211208103337.GA4047@kili \
    --to=dan.carpenter@oracle.com \
    --cc=eperezma@redhat.com \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=mst@redhat.com \
    --cc=tiwei.bie@intel.com \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=xieyongji@bytedance.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).