On Wed, Feb 27, 2019 at 08:48:56AM +0100, Michał Mirosław wrote: > gserial_alloc_line() misses locking (for a release barrier) while > resetting port entry on TTY allocation failure. Fix this. > > Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> > --- > drivers/usb/gadget/function/u_serial.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c > index 65f634ec7fc2..bb1e2e1d0076 100644 > --- a/drivers/usb/gadget/function/u_serial.c > +++ b/drivers/usb/gadget/function/u_serial.c > @@ -1239,8 +1239,10 @@ int gserial_alloc_line(unsigned char *line_num) > __func__, port_num, PTR_ERR(tty_dev)); > > ret = PTR_ERR(tty_dev); > + mutex_lock(&ports[port_num].lock); > port = ports[port_num].port; > ports[port_num].port = NULL; > + mutex_unlock(&ports[port_num].lock); > gserial_free_port(port); > goto err; > } Should this be backported to stable kernels to resolve this issue? thanks, greg k-h
