[PATCH] ISDN: check for userspace copy faults

Most of the ISDN ->readstat() implementations needed to check
copy_to_user() and put_user() return values.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/isdn/capi/capidrv.c

@@ -1907,7 +1907,8 @@ static int if_readstat(u8 __user *buf, int len, int id, int channel)
 	}
 
 	for (p=buf, count=0; count < len; p++, count++) {
-		put_user(*card->q931_read++, p);
+		if (put_user(*card->q931_read++, p))
+			return -EFAULT;
 	        if (card->q931_read > card->q931_end)
 	                card->q931_read = card->q931_buf;
 	}

drivers/isdn/hisax/config.c

@@ -631,7 +631,8 @@ static int HiSax_readstatus(u_char __user *buf, int len, int id, int channel)
 		count = cs->status_end - cs->status_read + 1;
 		if (count >= len)
 			count = len;
-		copy_to_user(p, cs->status_read, count);
+		if (copy_to_user(p, cs->status_read, count))
+			return -EFAULT;
 		cs->status_read += count;
 		if (cs->status_read > cs->status_end)
 			cs->status_read = cs->status_buf;
@@ -642,7 +643,8 @@ static int HiSax_readstatus(u_char __user *buf, int len, int id, int channel)
 				cnt = HISAX_STATUS_BUFSIZE;
 			else
 				cnt = count;
-			copy_to_user(p, cs->status_read, cnt);
+			if (copy_to_user(p, cs->status_read, cnt))
+				return -EFAULT;
 			p += cnt;
 			cs->status_read += cnt % HISAX_STATUS_BUFSIZE;
 			count -= cnt;

drivers/isdn/icn/icn.c

@@ -1010,7 +1010,8 @@ icn_readstatus(u_char __user *buf, int len, icn_card * card)
 	for (p = buf, count = 0; count < len; p++, count++) {
 		if (card->msg_buf_read == card->msg_buf_write)
 			return count;
-		put_user(*card->msg_buf_read++, p);
+		if (put_user(*card->msg_buf_read++, p))
+			return -EFAULT;
 		if (card->msg_buf_read > card->msg_buf_end)
 			card->msg_buf_read = card->msg_buf;
 	}

drivers/isdn/isdnloop/isdnloop.c

@@ -446,7 +446,8 @@ isdnloop_readstatus(u_char __user *buf, int len, isdnloop_card * card)
 	for (p = buf, count = 0; count < len; p++, count++) {
 		if (card->msg_buf_read == card->msg_buf_write)
 			return count;
-		put_user(*card->msg_buf_read++, p);
+		if (put_user(*card->msg_buf_read++, p))
+			return -EFAULT;
 		if (card->msg_buf_read > card->msg_buf_end)
 			card->msg_buf_read = card->msg_buf;
 	}

drivers/isdn/pcbit/drv.c

@@ -725,23 +725,27 @@ static int pcbit_stat(u_char __user *buf, int len, int driver, int channel)
 
 	if (stat_st < stat_end)
 	{
-		copy_to_user(buf, statbuf + stat_st, len);
+		if (copy_to_user(buf, statbuf + stat_st, len))
+			return -EFAULT;
 		stat_st += len;	   
 	}
 	else
 	{
 		if (len > STATBUF_LEN - stat_st)
 		{
-			copy_to_user(buf, statbuf + stat_st, 
-				       STATBUF_LEN - stat_st);
-			copy_to_user(buf, statbuf, 
-				       len - (STATBUF_LEN - stat_st));
+			if (copy_to_user(buf, statbuf + stat_st,
+				       STATBUF_LEN - stat_st))
+				return -EFAULT;
+			if (copy_to_user(buf, statbuf,
+				       len - (STATBUF_LEN - stat_st)))
+				return -EFAULT;
 
 			stat_st = len - (STATBUF_LEN - stat_st);
 		}
 		else
 		{
-			copy_to_user(buf, statbuf + stat_st, len);
+			if (copy_to_user(buf, statbuf + stat_st, len))
+				return -EFAULT;
 
 			stat_st += len;