2019-01-22 12:46:53

by liujian (CE)

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

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

2019-01-22 12:46:53

by liujian (CE)

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

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 <[email protected]>
Reviewed-by: Hamish Martin <[email protected]>
---
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

2019-01-22 12:47:15

by liujian (CE)

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

'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 <[email protected]>
Reviewed-by: Hamish Martin <[email protected]>
---
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