From: Alan Stern <stern@rowland.harvard.edu>
Date: Fri, 9 Oct 2009 16:43:12 +0000 (-0400)
Subject: USB: serial: don't call release without attach
X-Git-Tag: v2.6.31.5~34
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=dd02f3999f68aadaf7b3e61586fda3f5caac3ead;p=karo-tx-linux.git

USB: serial: don't call release without attach

commit a4720c650b68a5fe7faed2edeb0ad12645f7ae63 upstream.

This patch (as1295) fixes a recently-added bug in the USB serial core.
If certain kinds of errors occur during probing, the core may call a
serial driver's release method without previously calling the attach
method.  This causes some drivers (io_ti in particular) to perform an
invalid memory access.

The patch adds a new flag to keep track of whether or not attach has
been called.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index a0702db4e9a7..3292e0391e28 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -155,7 +155,8 @@ static void destroy_serial(struct kref *kref)
 	if (serial->minor != SERIAL_TTY_NO_MINOR)
 		return_serial(serial);
 
-	serial->type->release(serial);
+	if (serial->attached)
+		serial->type->release(serial);
 
 	/* Now that nothing is using the ports, they can be freed */
 	for (i = 0; i < serial->num_port_pointers; ++i) {
@@ -1060,12 +1061,15 @@ int usb_serial_probe(struct usb_interface *interface,
 		module_put(type->driver.owner);
 		if (retval < 0)
 			goto probe_error;
+		serial->attached = 1;
 		if (retval > 0) {
 			/* quietly accept this device, but don't bind to a
 			   serial port as it's about to disappear */
 			serial->num_ports = 0;
 			goto exit;
 		}
+	} else {
+		serial->attached = 1;
 	}
 
 	if (get_free_serial(serial, num_ports, &minor) == NULL) {
diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 73f121ef4de0..20b12f3207ae 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -148,6 +148,7 @@ struct usb_serial {
 	struct usb_interface		*interface;
 	unsigned char			disconnected:1;
 	unsigned char			suspending:1;
+	unsigned char			attached:1;
 	unsigned char			minor;
 	unsigned char			num_ports;
 	unsigned char			num_port_pointers;