2014-03-28 20:26:29

by Alexey Khoroshilov

Subject: [PATCH] rtl8187: fix use after free on failure path in rtl8187_probe()

If allocation of io_dmabuf fails, rtl8187_probe() calls usb_put_dev(udev)
while usb_get_dev(udev) is not called yet. As a result refcnt is decremented
incorrectly and usb_dev can be used after memory deallocation.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
drivers/net/wireless/rtl818x/rtl8187/dev.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/rtl818x/rtl8187/dev.c b/drivers/net/wireless/rtl818x/rtl8187/dev.c
index fd78df813a85..d7f540a9dc9b 100644
--- a/drivers/net/wireless/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c
@@ -1636,10 +1636,10 @@ static int rtl8187_probe(struct usb_interface *intf,

err_free_dmabuf:
kfree(priv->io_dmabuf);
- err_free_dev:
- ieee80211_free_hw(dev);
usb_set_intfdata(intf, NULL);
usb_put_dev(udev);
+ err_free_dev:
+ ieee80211_free_hw(dev);
return err;
}

--
1.8.3.2

2014-03-30 21:31:35

by Larry Finger

Subject: Re: [PATCH] rtl8187: fix use after free on failure path in rtl8187_probe()

On 03/28/2014 03:26 PM, Alexey Khoroshilov wrote:
> If allocation of io_dmabuf fails, rtl8187_probe() calls usb_put_dev(udev)
> while usb_get_dev(udev) is not called yet. As a result refcnt is decremented
> incorrectly and usb_dev can be used after memory deallocation.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> ---

Acked-by: Larry Finger <[email protected]>

Thanks,

Larry

> drivers/net/wireless/rtl818x/rtl8187/dev.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/rtl818x/rtl8187/dev.c b/drivers/net/wireless/rtl818x/rtl8187/dev.c
> index fd78df813a85..d7f540a9dc9b 100644
> --- a/drivers/net/wireless/rtl818x/rtl8187/dev.c
> +++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c
> @@ -1636,10 +1636,10 @@ static int rtl8187_probe(struct usb_interface *intf,
>
> err_free_dmabuf:
> kfree(priv->io_dmabuf);
> - err_free_dev:
> - ieee80211_free_hw(dev);
> usb_set_intfdata(intf, NULL);
> usb_put_dev(udev);
> + err_free_dev:
> + ieee80211_free_hw(dev);
> return err;
> }
>
>

2014-04-08 00:19:13

by Hin-Tak Leung

Subject: Re: [PATCH] rtl8187: fix use after free on failure path in rtl8187_probe()

------------------------------
On Sun, Mar 30, 2014 10:31 PM BST Larry Finger wrote:

>On 03/28/2014 03:26 PM, Alexey Khoroshilov wrote:
> If allocation of io_dmabuf fails, rtl8187_probe() calls usb_put_dev(udev)
> while usb_get_dev(udev) is not called yet. As a result refcnt is decremented
> incorrectly and usb_dev can be used after memory deallocation.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> ---
>
>Acked-by: Larry Finger <[email protected]>
>
>Thanks,
>
>Larry

Acked-by: Hin-Tak Leung <[email protected]>

Hin-Tak

>
>???drivers/net/wireless/rtl818x/rtl8187/dev.c | 4 ++--
>???1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/rtl818x/rtl8187/dev.c b/drivers/net/wireless/rtl818x/rtl8187/dev.c
> index fd78df813a85..d7f540a9dc9b 100644
> --- a/drivers/net/wireless/rtl818x/rtl8187/dev.c
> +++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c
> @@ -1636,10 +1636,10 @@ static int rtl8187_probe(struct usb_interface *intf,
>
>? ? err_free_dmabuf:
>?????? kfree(priv->io_dmabuf);
> - err_free_dev:
> -??? ieee80211_free_hw(dev);
>?????? usb_set_intfdata(intf, NULL);
>?????? usb_put_dev(udev);
> + err_free_dev:
> +??? ieee80211_free_hw(dev);
>?????? return err;
>???}
>
>
>