| From e6598326c230e61d73193ab499a417dc88adae00 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 8 Apr 2021 15:16:01 +0200 |
| Subject: USB: cdc-acm: fix unprivileged TIOCCSERIAL |
| |
| From: Johan Hovold <johan@kernel.org> |
| |
| [ Upstream commit dd5619582d60007139f0447382d2839f4f9e339b ] |
| |
| TIOCSSERIAL is a horrid, underspecified, legacy interface which for most |
| serial devices is only useful for setting the close_delay and |
| closing_wait parameters. |
| |
| A non-privileged user has only ever been able to set the since long |
| deprecated ASYNC_SPD flags and trying to change any other *supported* |
| feature should result in -EPERM being returned. Setting the current |
| values for any supported features should return success. |
| |
| Fix the cdc-acm implementation which instead indicated that the |
| TIOCSSERIAL ioctl was not even implemented when a non-privileged user |
| set the current values. |
| |
| Fixes: ba2d8ce9db0a ("cdc-acm: implement TIOCSSERIAL to avoid blocking close(2)") |
| Acked-by: Oliver Neukum <oneukum@suse.com> |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Link: https://lore.kernel.org/r/20210408131602.27956-3-johan@kernel.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/usb/class/cdc-acm.c | 2 -- |
| 1 file changed, 2 deletions(-) |
| |
| diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c |
| index 8c476a785360..0478d55bd283 100644 |
| --- a/drivers/usb/class/cdc-acm.c |
| +++ b/drivers/usb/class/cdc-acm.c |
| @@ -883,8 +883,6 @@ static int set_serial_info(struct acm *acm, |
| if ((new_serial.close_delay != old_close_delay) || |
| (new_serial.closing_wait != old_closing_wait)) |
| retval = -EPERM; |
| - else |
| - retval = -EOPNOTSUPP; |
| } else { |
| acm->port.close_delay = close_delay; |
| acm->port.closing_wait = closing_wait; |
| -- |
| 2.30.2 |
| |
