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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
Cc: netdev@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch] caif: add a sanity check to the tty name
Date: Tue, 03 Sep 2013 09:02:32 +0000	[thread overview]
Message-ID: <20130903090232.GA4351@elgon.mountain> (raw)

"tty->name" and "name" are a 64 character buffers.  My static checker
complains because we add the "cf" on the front so it look like we are
copying a 66 character string into a 64 character buffer.

Also if the name is larger than IFNAMSIZ (16) it triggers a BUG_ON()
inside the call to alloc_netdev().

This is all under CAP_SYS_ADMIN so it's not a security fix, it just adds
a little robustness.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c
index 34dea95..88a6a58 100644
--- a/drivers/net/caif/caif_serial.c
+++ b/drivers/net/caif/caif_serial.c
@@ -347,7 +347,9 @@ static int ldisc_open(struct tty_struct *tty)
 	/* release devices to avoid name collision */
 	ser_release(NULL);
 
-	sprintf(name, "cf%s", tty->name);
+	result = snprintf(name, sizeof(name), "cf%s", tty->name);
+	if (result >= IFNAMSIZ)
+		return -EINVAL;
 	dev = alloc_netdev(sizeof(*ser), name, caifdev_setup);
 	if (!dev)
 		return -ENOMEM;

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
Cc: netdev@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch] caif: add a sanity check to the tty name
Date: Tue, 3 Sep 2013 12:02:32 +0300	[thread overview]
Message-ID: <20130903090232.GA4351@elgon.mountain> (raw)

"tty->name" and "name" are a 64 character buffers.  My static checker
complains because we add the "cf" on the front so it look like we are
copying a 66 character string into a 64 character buffer.

Also if the name is larger than IFNAMSIZ (16) it triggers a BUG_ON()
inside the call to alloc_netdev().

This is all under CAP_SYS_ADMIN so it's not a security fix, it just adds
a little robustness.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c
index 34dea95..88a6a58 100644
--- a/drivers/net/caif/caif_serial.c
+++ b/drivers/net/caif/caif_serial.c
@@ -347,7 +347,9 @@ static int ldisc_open(struct tty_struct *tty)
 	/* release devices to avoid name collision */
 	ser_release(NULL);
 
-	sprintf(name, "cf%s", tty->name);
+	result = snprintf(name, sizeof(name), "cf%s", tty->name);
+	if (result >= IFNAMSIZ)
+		return -EINVAL;
 	dev = alloc_netdev(sizeof(*ser), name, caifdev_setup);
 	if (!dev)
 		return -ENOMEM;

             reply	other threads:[~2013-09-03  9:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-03  9:02 Dan Carpenter [this message]
2013-09-03  9:02 ` [patch] caif: add a sanity check to the tty name Dan Carpenter
2013-09-03 10:47 ` Dmitry Tarnyagin
2013-09-03 10:47   ` Dmitry Tarnyagin
2013-09-04  4:54 ` David Miller
2013-09-04  4:54   ` David Miller

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