diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index 9b856e1890d1..89b09c51ab7c 100644
--- a/drivers/isdn/i4l/isdn_common.c
+++ b/drivers/isdn/i4l/isdn_common.c
@@ -1304,9 +1304,6 @@ isdn_ioctl(struct file *file, uint cmd, ulong arg)
 			if (arg) {
 				ulong __user *p = argp;
 				int i;
-				if (!access_ok(VERIFY_WRITE, p,
-					       sizeof(ulong) * ISDN_MAX_CHANNELS * 2))
-					return -EFAULT;
 				for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
 					put_user(dev->ibytes[i], p++);
 					put_user(dev->obytes[i], p++);
@@ -1540,11 +1537,6 @@ isdn_ioctl(struct file *file, uint cmd, ulong arg)
 				char __user *p = argp;
 				int i;
 
-				if (!access_ok(VERIFY_WRITE, argp,
-					       (ISDN_MODEM_NUMREG + ISDN_MSNLEN + ISDN_LMSNLEN)
-					       * ISDN_MAX_CHANNELS))
-					return -EFAULT;
-
 				for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
 					if (copy_to_user(p, dev->mdm.info[i].emu.profile,
 							 ISDN_MODEM_NUMREG))
@@ -1567,11 +1559,6 @@ isdn_ioctl(struct file *file, uint cmd, ulong arg)
 				char __user *p = argp;
 				int i;
 
-				if (!access_ok(VERIFY_READ, argp,
-					       (ISDN_MODEM_NUMREG + ISDN_MSNLEN + ISDN_LMSNLEN)
-					       * ISDN_MAX_CHANNELS))
-					return -EFAULT;
-
 				for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
 					if (copy_from_user(dev->mdm.info[i].emu.profile, p,
 							   ISDN_MODEM_NUMREG))
@@ -1617,8 +1604,6 @@ isdn_ioctl(struct file *file, uint cmd, ulong arg)
 						int j = 0;
 
 						while (1) {
-							if (!access_ok(VERIFY_READ, p, 1))
-								return -EFAULT;
 							get_user(bname[j], p++);
 							switch (bname[j]) {
 							case '\0':
@@ -1685,9 +1670,6 @@ isdn_ioctl(struct file *file, uint cmd, ulong arg)
 					drvidx = 0;
 				if (drvidx == -1)
 					return -ENODEV;
-				if (!access_ok(VERIFY_WRITE, argp,
-					       sizeof(isdn_ioctl_struct)))
-					return -EFAULT;
 				c.driver = drvidx;
 				c.command = ISDN_CMD_IOCTL;
 				c.arg = cmd;
diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c
index d07dd5196ffc..487478bafaf5 100644
--- a/drivers/isdn/i4l/isdn_ppp.c
+++ b/drivers/isdn/i4l/isdn_ppp.c
@@ -795,9 +795,6 @@ isdn_ppp_read(int min, struct file *file, char __user *buf, int count)
 	if (!(is->state & IPPP_OPEN))
 		return 0;
 
-	if (!access_ok(VERIFY_WRITE, buf, count))
-		return -EFAULT;
-
 	spin_lock_irqsave(&is->buflock, flags);
 	b = is->first->next;
 	save_buf = b->buf;
@@ -2014,9 +2011,6 @@ isdn_ppp_dev_ioctl_stats(int slot, struct ifreq *ifr, struct net_device *dev)
 	struct ppp_stats t;
 	isdn_net_local *lp = netdev_priv(dev);
 
-	if (!access_ok(VERIFY_WRITE, res, sizeof(struct ppp_stats)))
-		return -EFAULT;
-
 	/* build a temporary stat struct and copy it to user space */
 
 	memset(&t, 0, sizeof(struct ppp_stats));
diff --git a/drivers/isdn/isdnloop/isdnloop.c b/drivers/isdn/isdnloop/isdnloop.c
index ef9c8e4f1fa2..32cb0cbd7217 100644
--- a/drivers/isdn/isdnloop/isdnloop.c
+++ b/drivers/isdn/isdnloop/isdnloop.c
@@ -1142,8 +1142,6 @@ isdnloop_command(isdn_ctrl *c, isdnloop_card *card)
 		case ISDNLOOP_IOCTL_DEBUGVAR:
 			return (ulong) card;
 		case ISDNLOOP_IOCTL_STARTUP:
-			if (!access_ok(VERIFY_READ, (void *) a, sizeof(isdnloop_sdef)))
-				return -EFAULT;
 			return isdnloop_start(card, (isdnloop_sdef *) a);
 			break;
 		case ISDNLOOP_IOCTL_ADDCARD: