From: Dan Carpenter <dan.carpenter@oracle.com>
To: netdev@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org
Subject: [patch] wan/x25_asy: integer overflow in x25_asy_change_mtu()
Date: Thu, 17 Jul 2014 08:03:10 +0000 [thread overview]
Message-ID: <20140717080310.GB477@mwanda> (raw)
If "newmtu * 2 + 4" is too large then it can cause an integer overflow
leading to memory corruption. Btw, "newmtu" is not allowed to be a
negative number because of the check in dev_set_mtu(), so that's ok.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c
index 5895f19..f04c8c1 100644
--- a/drivers/net/wan/x25_asy.c
+++ b/drivers/net/wan/x25_asy.c
@@ -122,8 +122,11 @@ static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
{
struct x25_asy *sl = netdev_priv(dev);
unsigned char *xbuff, *rbuff;
- int len = 2 * newmtu;
+ int len;
+ if (newmtu > INT_MAX / 2 - 4)
+ return -EINVAL;
+ len = 2 * newmtu;
xbuff = kmalloc(len + 4, GFP_ATOMIC);
rbuff = kmalloc(len + 4, GFP_ATOMIC);
WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: netdev@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org
Subject: [patch] wan/x25_asy: integer overflow in x25_asy_change_mtu()
Date: Thu, 17 Jul 2014 11:03:10 +0300 [thread overview]
Message-ID: <20140717080310.GB477@mwanda> (raw)
If "newmtu * 2 + 4" is too large then it can cause an integer overflow
leading to memory corruption. Btw, "newmtu" is not allowed to be a
negative number because of the check in dev_set_mtu(), so that's ok.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c
index 5895f19..f04c8c1 100644
--- a/drivers/net/wan/x25_asy.c
+++ b/drivers/net/wan/x25_asy.c
@@ -122,8 +122,11 @@ static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
{
struct x25_asy *sl = netdev_priv(dev);
unsigned char *xbuff, *rbuff;
- int len = 2 * newmtu;
+ int len;
+ if (newmtu > INT_MAX / 2 - 4)
+ return -EINVAL;
+ len = 2 * newmtu;
xbuff = kmalloc(len + 4, GFP_ATOMIC);
rbuff = kmalloc(len + 4, GFP_ATOMIC);
next reply other threads:[~2014-07-17 8:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-17 8:03 Dan Carpenter [this message]
2014-07-17 8:03 ` [patch] wan/x25_asy: integer overflow in x25_asy_change_mtu() Dan Carpenter
2014-07-17 8:45 ` David Laight
2014-07-17 8:58 ` Dan Carpenter
2014-07-17 8:58 ` Dan Carpenter
2014-07-17 9:14 ` Eric Dumazet
2014-07-17 9:14 ` Eric Dumazet
2014-07-17 10:50 ` [patch v2] " Dan Carpenter
2014-07-17 10:50 ` Dan Carpenter
2014-07-17 23:48 ` David Miller
2014-07-17 23:48 ` David Miller
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=20140717080310.GB477@mwanda \
--to=dan.carpenter@oracle.com \
--cc=kernel-janitors@vger.kernel.org \
--cc=netdev@vger.kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.