2012-11-14 06:32:56

by Kumar Amit Mehta

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

This fix adds checks for inspecting the return value of put_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 e125b03..b294197 100644
--- a/drivers/staging/dgrp/dgrp_tty.c
+++ b/drivers/staging/dgrp/dgrp_tty.c
@@ -2265,7 +2265,8 @@ static int get_modem_info(struct ch_struct *ch, unsigned int *value)
| ((mlast & DM_RI) ? TIOCM_RNG : 0)
| ((mlast & DM_DSR) ? TIOCM_DSR : 0)
| ((mlast & DM_CTS) ? TIOCM_CTS : 0);
- put_user(mlast, (unsigned int __user *) value);
+ if (put_user(mlast, (unsigned int __user *) value))
+ return -EFAULT;

return 0;
}
@@ -2620,7 +2621,8 @@ static int dgrp_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
sizeof(long));
if (rc == 0)
return -EFAULT;
- put_user(C_CLOCAL(tty) ? 1 : 0, (unsigned long __user *) arg);
+ if (put_user(C_CLOCAL(tty) ? 1 : 0, (unsigned long __user *) arg))
+ return -EFAULT;
return 0;

case TIOCSSOFTCAR:
@@ -2854,7 +2856,8 @@ static int dgrp_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
rc = access_ok(VERIFY_WRITE, (void __user *) arg, sizeof(int));
if (rc == 0)
return -EFAULT;
- put_user(ch->ch_custom_speed, (unsigned int __user *) arg);
+ if (put_user(ch->ch_custom_speed, (unsigned int __user *) arg))
+ return -EFAULT;
break;

case DIGI_SETCUSTOMBAUD:
--
1.7.9.5

2012-11-14 11:52:27

by Alan

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

On Wed, 14 Nov 2012 12:02:21 +0530
Kumar Amit Mehta <[email protected]> wrote:

> This fix adds checks for inspecting the return value of put_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 e125b03..b294197 100644
> --- a/drivers/staging/dgrp/dgrp_tty.c
> +++ b/drivers/staging/dgrp/dgrp_tty.c
> @@ -2265,7 +2265,8 @@ static int get_modem_info(struct ch_struct *ch, unsigned int *value)
> | ((mlast & DM_RI) ? TIOCM_RNG : 0)
> | ((mlast & DM_DSR) ? TIOCM_DSR : 0)
> | ((mlast & DM_CTS) ? TIOCM_CTS : 0);
> - put_user(mlast, (unsigned int __user *) value);
> + if (put_user(mlast, (unsigned int __user *) value))
> + return -EFAULT;


return put_user(mlast, ....)

is shorter and neater and does the same thing.

Alan