diff mbox

ax25: unsigned cannot be less than 0 in ax25_ctl_ioctl()

Message ID 4AD5EDA6.4040709@gmail.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

roel kluin Oct. 14, 2009, 3:26 p.m. UTC 
struct ax25_ctl_struct member `arg' is unsigned and cannot be less
than 0.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
Op 12-10-09 23:58, Kevin Dawson schreef:

>>>  tmp_arg=ax25_ctl.arg * HZ;
>>>
>>>   if (arg == 0 || arg >  ULONG_MAX )
>>>         goto einval_put;
>>
>> I'm not sure, I think this would only work if we made `arg' an
>> unsigned long long.
> 
> That depends on the possible values of ax25_ctl.arg.
> 
>> +    if (ax25_ctl.arg * HZ > ULONG_MAX && ax25_ctl.cmd != AX25_KILL)
>> +        return -EINVAL;
> 
> Why the need to change arg before comparing it with a constant?  Let the
> compiler do the work:
> 
>     if (ax25_ctl.arg > ULONG_MAX / HZ && ...

Ok, How about this then?

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

David Miller Oct. 30, 2009, 6:06 a.m. UTC | #1 
From: Roel Kluin <roel.kluin@gmail.com>
Date: Wed, 14 Oct 2009 17:26:30 +0200

> struct ax25_ctl_struct member `arg' is unsigned and cannot be less
> than 0.
> 
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>

Applied to net-next-2.6
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index f454607..d923ac4 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -369,6 +369,9 @@  static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg)
 	if (ax25_ctl.digi_count > AX25_MAX_DIGIS)
 		return -EINVAL;
 
+	if (ax25_ctl.arg > ULONG_MAX / HZ && ax25_ctl.cmd != AX25_KILL)
+		return -EINVAL;
+
 	digi.ndigi = ax25_ctl.digi_count;
 	for (k = 0; k < digi.ndigi; k++)
 		digi.calls[k] = ax25_ctl.digi_addr[k];
@@ -418,14 +421,10 @@  static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg)
 		break;
 
 	case AX25_T3:
-		if (ax25_ctl.arg < 0)
-			goto einval_put;
 		ax25->t3 = ax25_ctl.arg * HZ;
 		break;
 
 	case AX25_IDLE:
-		if (ax25_ctl.arg < 0)
-			goto einval_put;
 		ax25->idle = ax25_ctl.arg * 60 * HZ;
 		break;