2012-11-14 09:16:18

by Kumar Amit Mehta

Subject: [PATCH] staging: dgrp: dgrp_tty.c: return an -EFAULT if get_user() fails

Inspect the return value of get_user() and return -EFAULT on error.

Signed-off-by: Kumar Amit Mehta <[email protected]>
---
drivers/staging/dgrp/dgrp_tty.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/dgrp/dgrp_tty.c b/drivers/staging/dgrp/dgrp_tty.c
index b294197..720940f 100644
--- a/drivers/staging/dgrp/dgrp_tty.c
+++ b/drivers/staging/dgrp/dgrp_tty.c
@@ -2286,7 +2286,8 @@ static int set_modem_info(struct ch_struct *ch, unsigned int command,
if (error == 0)
return -EFAULT;

- get_user(arg, (unsigned int __user *) value);
+ if (get_user(arg, (unsigned int __user *) value))
+ return -EFAULT;
mval |= ((arg & TIOCM_RTS) ? DM_RTS : 0)
| ((arg & TIOCM_DTR) ? DM_DTR : 0);

@@ -2626,7 +2627,8 @@ static int dgrp_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
return 0;

case TIOCSSOFTCAR:
- get_user(arg, (unsigned long __user *) arg);
+ if (get_user(arg, (unsigned long __user *) arg))
+ return -EFAULT;
tty->termios.c_cflag =
((tty->termios.c_cflag & ~CLOCAL) |
(arg ? CLOCAL : 0));
@@ -2864,7 +2866,8 @@ static int dgrp_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
{
int new_rate;

- get_user(new_rate, (unsigned int __user *) arg);
+ if (get_user(new_rate, (unsigned int __user *) arg))
+ return -EFAULT;
dgrp_set_custom_speed(ch, new_rate);

break;
--
1.7.9.5

2012-11-14 11:50:26

by Alan

Subject: Re: [PATCH] staging: dgrp: dgrp_tty.c: return an -EFAULT if get_user() fails

On Wed, 14 Nov 2012 13:11:18 +0530
Kumar Amit Mehta <[email protected]> wrote:

> Inspect the return value of get_user() and return -EFAULT on error.

You cam just delete all the TIOCSOFTCAR nonsense. That ioctl is handled
correctly by the core tty layer code rather than incorrectly by the dgrp
driver.

Alan