USB: serial: don't call release without attach
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>
CC: stable <stable@kernel.org>
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 aa6b2ae..2d0f75d 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -156,7 +156,8 @@
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 @@
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 c17eb64..ce911eb 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -150,6 +150,7 @@
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;