From: Hillf Danton <dhillf@gmail.com>
Date: Thu, 31 Mar 2011 12:38:47 +0000 (+0800)
Subject: uio: fix allocating minor id for uio device
X-Git-Tag: v3.0-rc1~390^2~34
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=c6edc42fe1b5562abae22beabbebd9e557527ae3;p=linux.git

uio: fix allocating minor id for uio device

The number of uio devices that could be used should be less than
UIO_MAX_DEVICES by design, and this work guards any cases in which id
more than UIO_MAX_DEVICES is utilized.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Hans J. Koch <hjk@hansjkoch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 10a029b24159..d2efe823c20d 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -381,7 +381,13 @@ static int uio_get_minor(struct uio_device *idev)
 			retval = -ENOMEM;
 		goto exit;
 	}
-	idev->minor = id & MAX_ID_MASK;
+	if (id < UIO_MAX_DEVICES) {
+		idev->minor = id;
+	} else {
+		dev_err(idev->dev, "too many uio devices\n");
+		retval = -EINVAL;
+		idr_remove(&uio_idr, id);
+	}
 exit:
 	mutex_unlock(&minor_lock);
 	return retval;