i2o: check return code from put_user()

Check return value of put_user() and return -EFAULT if it failed.
Original comment "We did a get user...so assuming mem is ok...is this
bad?" is incorrect because memory can be read only.
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/message/i2o/i2o_config.c

@@ -111,9 +111,9 @@ static int i2o_cfg_gethrt(unsigned long arg)
 
 	len = 8 + ((hrt->entry_len * hrt->num_entries) << 2);
 
-	/* We did a get user...so assuming mem is ok...is this bad? */
-	put_user(len, kcmd.reslen);
-	if (len > reslen)
+	if (put_user(len, kcmd.reslen))
+		ret = -EFAULT;
+	else if (len > reslen)
 		ret = -ENOBUFS;
 	else if (copy_to_user(kcmd.resbuf, (void *)hrt, len))
 		ret = -EFAULT;
@@ -147,8 +147,9 @@ static int i2o_cfg_getlct(unsigned long arg)
 	lct = (i2o_lct *) c->lct;
 
 	len = (unsigned int)lct->table_size << 2;
-	put_user(len, kcmd.reslen);
-	if (len > reslen)
+	if (put_user(len, kcmd.reslen))
+		ret = -EFAULT;
+	else if (len > reslen)
 		ret = -ENOBUFS;
 	else if (copy_to_user(kcmd.resbuf, lct, len))
 		ret = -EFAULT;
@@ -208,8 +209,9 @@ static int i2o_cfg_parms(unsigned long arg, unsigned int type)
 		return -EAGAIN;
 	}
 
-	put_user(len, kcmd.reslen);
-	if (len > reslen)
+	if (put_user(len, kcmd.reslen))
+		ret = -EFAULT;
+	else if (len > reslen)
 		ret = -ENOBUFS;
 	else if (copy_to_user(kcmd.resbuf, res, len))
 		ret = -EFAULT;