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@xxxxxxxxxxxxxxxxxxx>
Tested-by: Jean-Denis Girard <jd.girard@xxxxxxxxx>
CC: stable@xxxxxxxxxx
---
Index: usb-2.6/include/linux/usb/serial.h
===================================================================
--- usb-2.6.orig/include/linux/usb/serial.h
+++ usb-2.6/include/linux/usb/serial.h
@@ -150,6 +150,7 @@ 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;
Index: usb-2.6/drivers/usb/serial/usb-serial.c
===================================================================
--- usb-2.6.orig/drivers/usb/serial/usb-serial.c
+++ usb-2.6/drivers/usb/serial/usb-serial.c
@@ -156,7 +156,8 @@ static void destroy_serial(struct 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) {
@@ -1059,12 +1060,15 @@ int usb_serial_probe(struct usb_interfac
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) {
--
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