2018-11-29 10:49:33

by Pan Bian

Subject: [PATCH] rtl818x: fix potential use after free

entry is released via usb_put_urb just after calling usb_submit_urb.
However, entry is used if the submission fails, resulting in a use after
free bug. The patch fixes this.

Signed-off-by: Pan Bian <[email protected]>
---
drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
index cec3778..1a2ea8b 100644
--- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
@@ -444,12 +444,13 @@ static int rtl8187_init_urbs(struct ieee80211_hw *dev)
skb_queue_tail(&priv->rx_queue, skb);
usb_anchor_urb(entry, &priv->anchored);
ret = usb_submit_urb(entry, GFP_KERNEL);
- usb_put_urb(entry);
if (ret) {
skb_unlink(skb, &priv->rx_queue);
usb_unanchor_urb(entry);
+ usb_put_urb(entry);
goto err;
}
+ usb_put_urb(entry);
}
return ret;

--
2.7.4

2018-11-29 15:11:14

by Larry Finger

Subject: Re: [PATCH] rtl818x: fix potential use after free

On 11/29/18 4:48 AM, Pan Bian wrote:
> entry is released via usb_put_urb just after calling usb_submit_urb.
> However, entry is used if the submission fails, resulting in a use after
> free bug. The patch fixes this.
>
> Signed-off-by: Pan Bian <[email protected]>
> ---
> drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> index cec3778..1a2ea8b 100644
> --- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> +++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> @@ -444,12 +444,13 @@ static int rtl8187_init_urbs(struct ieee80211_hw *dev)
> skb_queue_tail(&priv->rx_queue, skb);
> usb_anchor_urb(entry, &priv->anchored);
> ret = usb_submit_urb(entry, GFP_KERNEL);
> - usb_put_urb(entry);
> if (ret) {
> skb_unlink(skb, &priv->rx_queue);
> usb_unanchor_urb(entry);
> + usb_put_urb(entry);
> goto err;
> }
> + usb_put_urb(entry);
> }
> return ret;

Good catch.

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

Thanks,
Larry

2018-12-13 15:05:14

by Kalle Valo

Subject: Re: [PATCH] rtl818x: fix potential use after free

Pan Bian <[email protected]> wrote:

> entry is released via usb_put_urb just after calling usb_submit_urb.
> However, entry is used if the submission fails, resulting in a use after
> free bug. The patch fixes this.
>
> Signed-off-by: Pan Bian <[email protected]>
> ACKed-by: Larry Finger <[email protected]>

Patch applied to wireless-drivers-next.git, thanks.

afbb1947db94 rtl818x: fix potential use after free

--
https://patchwork.kernel.org/patch/10704331/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches