NET: AX.25: Check ioctl arguments to avoid overflows further down the…

… road. Very large, nonsenical arguments or use in very extreme conditions could result in integer overflows. Check ioctls arguments to avoid such overflows and return -EINVAL for too large arguments. To allow the use of AX.25 for even the most extreme setup (think packet radio to the Phase 5E mars probe) we make no further attempt to clamp the argument range. Originally reported by Fan Long <[email protected]> and a first patch was sent by Xi Wang <[email protected]>. Signed-off-by: Ralf Baechle <[email protected]> Cc: Xi Wang <[email protected]> Cc: Joerg Reuter <[email protected]> Cc: Alan Cox <[email protected]> Cc: Thomas Osterried <[email protected]> Signed-off-by: David S. Miller <[email protected]>
chewitt · Nov 29, 2011 · be639ac · be639ac
1 parent 3b15885
commit be639ac
Showing 1 changed file with 11 additions and 6 deletions.
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
@@ -402,14 +402,14 @@ static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg)
 		break;
 
 	case AX25_T1:
-		if (ax25_ctl.arg < 1)
+		if (ax25_ctl.arg < 1 || ax25_ctl.arg > ULONG_MAX / HZ)
 			goto einval_put;
 		ax25->rtt = (ax25_ctl.arg * HZ) / 2;
 		ax25->t1  = ax25_ctl.arg * HZ;
 		break;
 
 	case AX25_T2:
-		if (ax25_ctl.arg < 1)
+		if (ax25_ctl.arg < 1 || ax25_ctl.arg > ULONG_MAX / HZ)
 			goto einval_put;
 		ax25->t2 = ax25_ctl.arg * HZ;
 		break;
@@ -422,10 +422,15 @@ static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg)
 		break;
 
 	case AX25_T3:
+		if (ax25_ctl.arg > ULONG_MAX / HZ)
+			goto einval_put;
 		ax25->t3 = ax25_ctl.arg * HZ;
 		break;
 
 	case AX25_IDLE:
+		if (ax25_ctl.arg > ULONG_MAX / (60 * HZ))
+			goto einval_put;
+
 		ax25->idle = ax25_ctl.arg * 60 * HZ;
 		break;
 
@@ -571,7 +576,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T1:
-		if (opt < 1) {
+		if (opt < 1 || opt > ULONG_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -580,7 +585,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T2:
-		if (opt < 1) {
+		if (opt < 1 || opt > ULONG_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -596,15 +601,15 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T3:
-		if (opt < 1) {
+		if (opt < 1 || opt > ULONG_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
 		ax25->t3 = opt * HZ;
 		break;
 
 	case AX25_IDLE:
-		if (opt < 0) {
+		if (opt < 0 || opt > ULONG_MAX / (60 * HZ)) {
 			res = -EINVAL;
 			break;
 		}