Commit 4826a0be authored Mar 27, 2020 by Matthias Reichl Committed by Greg Kroah-Hartman Apr 02, 2020

USB: cdc-acm: restore capability check order



commit 62d65bdd9d05158aa2547f8ef72375535f3bc6e3 upstream.

commit b401f8c4f492c ("USB: cdc-acm: fix rounding error in TIOCSSERIAL")
introduced a regression by changing the order of capability and close
settings change checks. When running with CAP_SYS_ADMIN setting the
close settings to the values already set resulted in -EOPNOTSUPP.

Fix this by changing the check order back to how it was before.

Fixes: b401f8c4f492c ("USB: cdc-acm: fix rounding error in TIOCSSERIAL")
Cc: Anthony Mallet <anthony.mallet@laas.fr>
Cc: stable <stable@vger.kernel.org>
Cc: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Matthias Reichl <hias@horus.com>
Link: https://lore.kernel.org/r/20200327150350.3657-1-hias@horus.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ce6edbf0

drivers/usb/class/cdc-acm.c

+9 −9

Original line number	Original line	Diff line number	Diff line
	@@ -863,16 +863,16 @@ static int set_serial_info(struct acm *acm,

	mutex_lock(&acm->port.mutex);		mutex_lock(&acm->port.mutex);

			if (!capable(CAP_SYS_ADMIN)) {
	if ((new_serial.close_delay != old_close_delay) \|\|		if ((new_serial.close_delay != old_close_delay) \|\|
	(new_serial.closing_wait != old_closing_wait)) {		(new_serial.closing_wait != old_closing_wait))
	if (!capable(CAP_SYS_ADMIN))
	retval = -EPERM;		retval = -EPERM;
	else {		else
			retval = -EOPNOTSUPP;
			} else {
	acm->port.close_delay = close_delay;		acm->port.close_delay = close_delay;
	acm->port.closing_wait = closing_wait;		acm->port.closing_wait = closing_wait;
	}		}
	} else
	retval = -EOPNOTSUPP;

	mutex_unlock(&acm->port.mutex);		mutex_unlock(&acm->port.mutex);
	return retval;		return retval;