2012-11-22 19:46:59

by Kumar Amit Mehta

Subject: [PATCH 0/2] staging/dgrp/dgrp_tty.c: audit function return values

This patch series fixes two issues in dgrp driver:
i) Removes the TIOCSSOFTCAR ioctl handler from dgrp driver so as to allow the
core tty layer to take care of this ioctl instead.

ii) Audits the return value of get_user() and put_user() and return -EFAULT in
case of error.

--
1.7.9.5

2012-11-22 19:47:13

by Kumar Amit Mehta

Subject: [PATCH 2/2] staging: dgrp: dgrp_tty.c: Audit the return values of get/put_user()

fix for missing audits for return values of get_user() and put_user().
Inspecting the return values of get/put_user() would make the access_ok()
redundant, hence removing calls to access_ok() in such scenarios.

Signed-off-by: Kumar Amit Mehta <[email protected]>
---
drivers/staging/dgrp/dgrp_tty.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/dgrp/dgrp_tty.c b/drivers/staging/dgrp/dgrp_tty.c
index b46f56f..f4fdadc 100644
--- a/drivers/staging/dgrp/dgrp_tty.c
+++ b/drivers/staging/dgrp/dgrp_tty.c
@@ -2265,9 +2265,7 @@ 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);
-
- return 0;
+ return put_user(mlast, (unsigned int __user *) value);
}

/*
@@ -2285,7 +2283,8 @@ 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);

@@ -2616,12 +2615,8 @@ static int dgrp_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
return 0;

case TIOCGSOFTCAR:
- rc = access_ok(VERIFY_WRITE, (void __user *) arg,
- sizeof(long));
- if (rc == 0)
- return -EFAULT;
- put_user(C_CLOCAL(tty) ? 1 : 0, (unsigned long __user *) arg);
- return 0;
+ return put_user(C_CLOCAL(tty) ? 1 : 0,
+ (unsigned long __user *) arg);

case TIOCMGET:
rc = access_ok(VERIFY_WRITE, (void __user *) arg,
@@ -2844,17 +2839,16 @@ static int dgrp_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
break;

case DIGI_GETCUSTOMBAUD:
- rc = access_ok(VERIFY_WRITE, (void __user *) arg, sizeof(int));
- if (rc == 0)
+ if (put_user(ch->ch_custom_speed, (unsigned int __user *) arg))
return -EFAULT;
- put_user(ch->ch_custom_speed, (unsigned int __user *) arg);
break;

case DIGI_SETCUSTOMBAUD:
{
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

2012-11-22 19:48:38

by Kumar Amit Mehta

Subject: [PATCH 1/2] staging: dgrp: dgrp_tty.c: Remove the TIOCSSOFTCAR ioctl handler from dgrp driver

Remove the TIOCSSOFTCAR ioctl handler from dgrp driver and let the core tty
layer to take care of this ioctl instead.

Signed-off-by: Kumar Amit Mehta <[email protected]>
---
drivers/staging/dgrp/dgrp_tty.c | 7 -------
1 file changed, 7 deletions(-)

diff --git a/drivers/staging/dgrp/dgrp_tty.c b/drivers/staging/dgrp/dgrp_tty.c
index e125b03..b46f56f 100644
--- a/drivers/staging/dgrp/dgrp_tty.c
+++ b/drivers/staging/dgrp/dgrp_tty.c
@@ -2623,13 +2623,6 @@ static int dgrp_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
put_user(C_CLOCAL(tty) ? 1 : 0, (unsigned long __user *) arg);
return 0;

- case TIOCSSOFTCAR:
- get_user(arg, (unsigned long __user *) arg);
- tty->termios.c_cflag =
- ((tty->termios.c_cflag & ~CLOCAL) |
- (arg ? CLOCAL : 0));
- return 0;
-
case TIOCMGET:
rc = access_ok(VERIFY_WRITE, (void __user *) arg,
sizeof(unsigned int));
--
1.7.9.5