staging: fwserial: fix TIOCSSERIAL permission check
commit 2104eb283df66a482b60254299acbe3c68c03412 upstream.
Changing the port close-delay parameter is a privileged operation so
make sure to return -EPERM if a regular user tries to change it.
Fixes: 7355ba3445
("staging: fwserial: Add TTY-over-Firewire serial driver")
Cc: stable@vger.kernel.org # 3.8
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
ebb46274e3
commit
66ca71d283
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@ -1232,20 +1232,24 @@ static int set_serial_info(struct tty_struct *tty,
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struct serial_struct *ss)
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struct serial_struct *ss)
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{
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{
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struct fwtty_port *port = tty->driver_data;
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struct fwtty_port *port = tty->driver_data;
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unsigned int cdelay;
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if (ss->irq != 0 || ss->port != 0 || ss->custom_divisor != 0 ||
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if (ss->irq != 0 || ss->port != 0 || ss->custom_divisor != 0 ||
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ss->baud_base != 400000000)
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ss->baud_base != 400000000)
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return -EPERM;
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return -EPERM;
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cdelay = msecs_to_jiffies(ss->close_delay * 10);
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mutex_lock(&port->port.mutex);
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mutex_lock(&port->port.mutex);
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if (!capable(CAP_SYS_ADMIN)) {
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if (!capable(CAP_SYS_ADMIN)) {
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if (((ss->flags & ~ASYNC_USR_MASK) !=
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if (cdelay != port->port.close_delay ||
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((ss->flags & ~ASYNC_USR_MASK) !=
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(port->port.flags & ~ASYNC_USR_MASK))) {
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(port->port.flags & ~ASYNC_USR_MASK))) {
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mutex_unlock(&port->port.mutex);
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mutex_unlock(&port->port.mutex);
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return -EPERM;
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return -EPERM;
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}
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}
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}
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}
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port->port.close_delay = msecs_to_jiffies(ss->close_delay * 10);
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port->port.close_delay = cdelay;
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mutex_unlock(&port->port.mutex);
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mutex_unlock(&port->port.mutex);
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return 0;
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return 0;
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