[PATCH v2 0/2] fix possible memory leak and use-after-free in __uio_register_device

[PATCH v2 0/2] fix possible memory leak and use-after-free in __uio_register_device

[Liu Jian]

fix possible memory leak and use-after-free in __uio_register_device

v1->v2:
fix email From:line

Liu Jian (2):
  driver: uio: fix possible memory leak in __uio_register_device
  driver: uio: fix possible use-after-free in __uio_register_device

 drivers/uio/uio.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

-- 
2.7.4

[PATCH v2 1/2] driver: uio: fix possible memory leak in __uio_register_device

[Liu Jian]

'idev' is malloced in __uio_register_device() and leak free it before
leaving from the uio_get_minor() error handing case, it will cause
memory leak.

Fixes: a93e7b331568 ("uio: Prevent device destruction while fds are
open")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
---
 drivers/uio/uio.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index b4ae2d9..4d20220 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -941,8 +941,10 @@ int __uio_register_device(struct module *owner,
 	atomic_set(&idev->event, 0);
 
 	ret = uio_get_minor(idev);
-	if (ret)
+	if (ret) {
+		kfree(idev);
 		return ret;
+	}
 
 	idev->dev.devt = MKDEV(uio_major, idev->minor);
 	idev->dev.class = &uio_class;
-- 
2.7.4

[PATCH v2 2/2] driver: uio: fix possible use-after-free in __uio_register_device

[Liu Jian]

In uio_dev_add_attributes() error handing case, idev is used after
device_unregister(), in which 'idev' has been released, touch idev cause
use-after-free.

Fixes: a93e7b331568 ("uio: Prevent device destruction while fds are
open")

Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
---
 drivers/uio/uio.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 4d20220..7ee21c8 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -946,6 +946,7 @@ int __uio_register_device(struct module *owner,
 		return ret;
 	}
 
+	device_initialize(&idev->dev);
 	idev->dev.devt = MKDEV(uio_major, idev->minor);
 	idev->dev.class = &uio_class;
 	idev->dev.parent = parent;
@@ -956,7 +957,7 @@ int __uio_register_device(struct module *owner,
 	if (ret)
 		goto err_device_create;
 
-	ret = device_register(&idev->dev);
+	ret = device_add(&idev->dev);
 	if (ret)
 		goto err_device_create;
 
@@ -988,9 +989,10 @@ int __uio_register_device(struct module *owner,
 err_request_irq:
 	uio_dev_del_attributes(idev);
 err_uio_dev_add_attributes:
-	device_unregister(&idev->dev);
+	device_del(&idev->dev);
 err_device_create:
 	uio_free_minor(idev);
+	put_device(&idev->dev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(__uio_register_device);
-- 
2.7.4