linux-kernel - [PATCH 4.9 001/152] ppdev: check before attaching port

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

Message-Id: <20170410164200.009991245@linuxfoundation.org>
Date:   Mon, 10 Apr 2017 18:40:53 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Joe Lawrence <joe.lawrence@...hat.com>,
        Sudip Mukherjee <sudip.mukherjee@...ethink.co.uk>
Subject: [PATCH 4.9 001/152] ppdev: check before attaching port

4.9-stable review patch.  If anyone has any objections, please let me know.

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

From: Sudip Mukherjee <sudipm.mukherjee@...il.com>

commit dd5c472a60e43549d789a17a8444513eec64bd7e upstream.

After parport starts using the device model, all pardevice drivers
should decide in their match_port callback function if they want to
attach with that particulatr port. ppdev has been converted to use the
new parport device-model code but pp_attach() tried to attach with all
the ports.
Create a new array of pointer and use that to remember the ports we
have attached. And use that information to skip attaching ports which
we have already attached.

Tested-by: Joe Lawrence <joe.lawrence@...hat.com>
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@...ethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/char/ppdev.c |   23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

--- a/drivers/char/ppdev.c
+++ b/drivers/char/ppdev.c
@@ -86,6 +86,9 @@ struct pp_struct {
 	long default_inactivity;
 };
 
+/* should we use PARDEVICE_MAX here? */
+static struct device *devices[PARPORT_MAX];
+
 /* pp_struct.flags bitfields */
 #define PP_CLAIMED    (1<<0)
 #define PP_EXCL       (1<<1)
@@ -789,13 +792,29 @@ static const struct file_operations pp_f
 
 static void pp_attach(struct parport *port)
 {
-	device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
-		      NULL, "parport%d", port->number);
+	struct device *ret;
+
+	if (devices[port->number])
+		return;
+
+	ret = device_create(ppdev_class, port->dev,
+			    MKDEV(PP_MAJOR, port->number), NULL,
+			    "parport%d", port->number);
+	if (IS_ERR(ret)) {
+		pr_err("Failed to create device parport%d\n",
+		       port->number);
+		return;
+	}
+	devices[port->number] = ret;
 }
 
 static void pp_detach(struct parport *port)
 {
+	if (!devices[port->number])
+		return;
+
 	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
+	devices[port->number] = NULL;
 }
 
 static int pp_probe(struct pardevice *par_dev)