From: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> commit daf82bd24e308c5a83758047aff1bd81edda4f11 upstream. gserial_alloc_line() misses locking (for a release barrier) while resetting port entry on TTY allocation failure. Fix this. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Tested-by: Ladislav Michl <ladis@xxxxxxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/function/u_serial.c | 2 ++ 1 file changed, 2 insertions(+) --- 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 *li __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; }
