| Message ID | 20200116160705.5199-1-johan@kernel.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | fdb838efa31e1ed9a13ae6ad0b64e30fdbd00570 |
| Headers | show |
| Series | USB: serial: suppress driver bind attributes | expand |
On Thu, Jan 16, 2020 at 05:07:05PM +0100, Johan Hovold wrote: > USB-serial drivers must not be unbound from their ports before the > corresponding USB driver is unbound from the parent interface so > suppress the bind and unbind attributes. > > Unbinding a serial driver while it's port is open is a sure way to > trigger a crash as any driver state is released on unbind while port > hangup is handled on the parent USB interface level. Drivers for > multiport devices where ports share a resource such as an interrupt > endpoint also generally cannot handle individual ports going away. > > Cc: stable <stable@vger.kernel.org> > Signed-off-by: Johan Hovold <johan@kernel.org> > --- > drivers/usb/serial/usb-serial.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c > index 8f066bb55d7d..dc7a65b9ec98 100644 > --- a/drivers/usb/serial/usb-serial.c > +++ b/drivers/usb/serial/usb-serial.c > @@ -1317,6 +1317,9 @@ static int usb_serial_register(struct usb_serial_driver *driver) > return -EINVAL; > } > > + /* Prevent individual ports from being unbound. */ > + driver->driver.suppress_bind_attrs = true; We can still unbind the usb driver though, right? If so, this is fine with me. thanks, greg k-h
On Thu, Jan 16, 2020 at 05:18:29PM +0100, Greg Kroah-Hartman wrote: > On Thu, Jan 16, 2020 at 05:07:05PM +0100, Johan Hovold wrote: > > USB-serial drivers must not be unbound from their ports before the > > corresponding USB driver is unbound from the parent interface so > > suppress the bind and unbind attributes. > > > > Unbinding a serial driver while it's port is open is a sure way to > > trigger a crash as any driver state is released on unbind while port > > hangup is handled on the parent USB interface level. Drivers for > > multiport devices where ports share a resource such as an interrupt > > endpoint also generally cannot handle individual ports going away. > > > > Cc: stable <stable@vger.kernel.org> > > Signed-off-by: Johan Hovold <johan@kernel.org> > > --- > > drivers/usb/serial/usb-serial.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c > > index 8f066bb55d7d..dc7a65b9ec98 100644 > > --- a/drivers/usb/serial/usb-serial.c > > +++ b/drivers/usb/serial/usb-serial.c > > @@ -1317,6 +1317,9 @@ static int usb_serial_register(struct usb_serial_driver *driver) > > return -EINVAL; > > } > > > > + /* Prevent individual ports from being unbound. */ > > + driver->driver.suppress_bind_attrs = true; > > We can still unbind the usb driver though, right? If so, this is fine > with me. Right, this is only about disabling individual ports, something which essentially no subdriver can handle while a port is open (e.g. port-data set to NULL while port is still open... boom). Johan
On Thu, Jan 16, 2020 at 05:24:24PM +0100, Johan Hovold wrote: > On Thu, Jan 16, 2020 at 05:18:29PM +0100, Greg Kroah-Hartman wrote: > > On Thu, Jan 16, 2020 at 05:07:05PM +0100, Johan Hovold wrote: > > > USB-serial drivers must not be unbound from their ports before the > > > corresponding USB driver is unbound from the parent interface so > > > suppress the bind and unbind attributes. > > > > > > Unbinding a serial driver while it's port is open is a sure way to > > > trigger a crash as any driver state is released on unbind while port > > > hangup is handled on the parent USB interface level. Drivers for > > > multiport devices where ports share a resource such as an interrupt > > > endpoint also generally cannot handle individual ports going away. > > > > > > Cc: stable <stable@vger.kernel.org> > > > Signed-off-by: Johan Hovold <johan@kernel.org> > > > --- > > > drivers/usb/serial/usb-serial.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c > > > index 8f066bb55d7d..dc7a65b9ec98 100644 > > > --- a/drivers/usb/serial/usb-serial.c > > > +++ b/drivers/usb/serial/usb-serial.c > > > @@ -1317,6 +1317,9 @@ static int usb_serial_register(struct usb_serial_driver *driver) > > > return -EINVAL; > > > } > > > > > > + /* Prevent individual ports from being unbound. */ > > > + driver->driver.suppress_bind_attrs = true; > > > > We can still unbind the usb driver though, right? If so, this is fine > > with me. > > Right, this is only about disabling individual ports, something which > essentially no subdriver can handle while a port is open (e.g. port-data > set to NULL while port is still open... boom). Ok, thanks for verifying, and sorry for writing that bug in the first place :) Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Thu, Jan 16, 2020 at 08:06:06PM +0100, Greg Kroah-Hartman wrote: > On Thu, Jan 16, 2020 at 05:24:24PM +0100, Johan Hovold wrote: > > On Thu, Jan 16, 2020 at 05:18:29PM +0100, Greg Kroah-Hartman wrote: > > > On Thu, Jan 16, 2020 at 05:07:05PM +0100, Johan Hovold wrote: > > > > USB-serial drivers must not be unbound from their ports before the > > > > corresponding USB driver is unbound from the parent interface so > > > > suppress the bind and unbind attributes. > > > > > > > > Unbinding a serial driver while it's port is open is a sure way to > > > > trigger a crash as any driver state is released on unbind while port > > > > hangup is handled on the parent USB interface level. Drivers for > > > > multiport devices where ports share a resource such as an interrupt > > > > endpoint also generally cannot handle individual ports going away. > > > > > > > > Cc: stable <stable@vger.kernel.org> > > > > Signed-off-by: Johan Hovold <johan@kernel.org> > > > > --- > > > > drivers/usb/serial/usb-serial.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c > > > > index 8f066bb55d7d..dc7a65b9ec98 100644 > > > > --- a/drivers/usb/serial/usb-serial.c > > > > +++ b/drivers/usb/serial/usb-serial.c > > > > @@ -1317,6 +1317,9 @@ static int usb_serial_register(struct usb_serial_driver *driver) > > > > return -EINVAL; > > > > } > > > > > > > > + /* Prevent individual ports from being unbound. */ > > > > + driver->driver.suppress_bind_attrs = true; > > > > > > We can still unbind the usb driver though, right? If so, this is fine > > > with me. > > > > Right, this is only about disabling individual ports, something which > > essentially no subdriver can handle while a port is open (e.g. port-data > > set to NULL while port is still open... boom). > > Ok, thanks for verifying, and sorry for writing that bug in the first > place :) > > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Heh, thanks for reviewing. Johan
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 8f066bb55d7d..dc7a65b9ec98 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -1317,6 +1317,9 @@ static int usb_serial_register(struct usb_serial_driver *driver) return -EINVAL; } + /* Prevent individual ports from being unbound. */ + driver->driver.suppress_bind_attrs = true; + usb_serial_operations_init(driver); /* Add this device to our list of devices */
USB-serial drivers must not be unbound from their ports before the corresponding USB driver is unbound from the parent interface so suppress the bind and unbind attributes. Unbinding a serial driver while it's port is open is a sure way to trigger a crash as any driver state is released on unbind while port hangup is handled on the parent USB interface level. Drivers for multiport devices where ports share a resource such as an interrupt endpoint also generally cannot handle individual ports going away. Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org> --- drivers/usb/serial/usb-serial.c | 3 +++ 1 file changed, 3 insertions(+)