From: Matthias Reichl <hias@xxxxxxxxx> 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@xxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Cc: Oliver Neukum <oneukum@xxxxxxxx> Signed-off-by: Matthias Reichl <hias@xxxxxxxxx> Link: https://lore.kernel.org/r/20200327150350.3657-1-hias@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -863,16 +863,16 @@ static int set_serial_info(struct acm *a mutex_lock(&acm->port.mutex); - if ((new_serial.close_delay != old_close_delay) || - (new_serial.closing_wait != old_closing_wait)) { - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN)) { + if ((new_serial.close_delay != old_close_delay) || + (new_serial.closing_wait != old_closing_wait)) retval = -EPERM; - else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } - } else - retval = -EOPNOTSUPP; + else + retval = -EOPNOTSUPP; + } else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } mutex_unlock(&acm->port.mutex); return retval;