[PATCH 10/44] uio: fix allocating minor id for uio device

Greg Kroah-Hartman
2011-05-20T00:19:48Z

From: Hillf Danton <dhillf@gmail.com>

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>
---
drivers/uio/uio.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 10a029b..d2efe82 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;
--
1.7.4.2