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authorJohan Hovold <johan@kernel.org>2021-04-07 13:23:20 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-04-07 18:22:06 +0300
commit2104eb283df66a482b60254299acbe3c68c03412 (patch)
tree4f50eaff4ae772cf74866e06f615e8b94c58f3ad /drivers/staging/fwserial
parent7a3791afdbd5a951b09a7689bba856bd9f6c6a9f (diff)
downloadlinux-2104eb283df66a482b60254299acbe3c68c03412.tar.xz
staging: fwserial: fix TIOCSSERIAL permission check
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: 7355ba3445f2 ("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>
Diffstat (limited to 'drivers/staging/fwserial')
-rw-r--r--drivers/staging/fwserial/fwserial.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c
index c963848522b1..440d11423812 100644
--- a/drivers/staging/fwserial/fwserial.c
+++ b/drivers/staging/fwserial/fwserial.c
@@ -1232,20 +1232,24 @@ static int set_serial_info(struct tty_struct *tty,
struct serial_struct *ss)
{
struct fwtty_port *port = tty->driver_data;
+ unsigned int cdelay;
if (ss->irq != 0 || ss->port != 0 || ss->custom_divisor != 0 ||
ss->baud_base != 400000000)
return -EPERM;
+ cdelay = msecs_to_jiffies(ss->close_delay * 10);
+
mutex_lock(&port->port.mutex);
if (!capable(CAP_SYS_ADMIN)) {
- if (((ss->flags & ~ASYNC_USR_MASK) !=
+ if (cdelay != port->port.close_delay ||
+ ((ss->flags & ~ASYNC_USR_MASK) !=
(port->port.flags & ~ASYNC_USR_MASK))) {
mutex_unlock(&port->port.mutex);
return -EPERM;
}
}
- port->port.close_delay = msecs_to_jiffies(ss->close_delay * 10);
+ port->port.close_delay = cdelay;
mutex_unlock(&port->port.mutex);
return 0;