2021-03-29 11:26:38

by Lv Yunlong

Subject: [PATCH] wireless/marvell/mwifiex: Fix a double free in mwifiex_send_tdls_action_frame

In mwifiex_send_tdls_action_frame, it calls mwifiex_construct_tdls_action_frame
(..,skb). The skb will be freed in mwifiex_construct_tdls_action_frame() when
it is failed. But when mwifiex_construct_tdls_action_frame() returns error,
the skb will be freed in the second time by dev_kfree_skb_any(skb).

My patch removes the redundant dev_kfree_skb_any(skb) when
mwifiex_construct_tdls_action_frame() failed.

Fixes: b23bce2965680 ("mwifiex: add tdls_mgmt handler support")
Signed-off-by: Lv Yunlong <[email protected]>
---
drivers/net/wireless/marvell/mwifiex/tdls.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/tdls.c b/drivers/net/wireless/marvell/mwifiex/tdls.c
index 97bb87c3676b..8d4d0a9cf6ac 100644
--- a/drivers/net/wireless/marvell/mwifiex/tdls.c
+++ b/drivers/net/wireless/marvell/mwifiex/tdls.c
@@ -856,7 +856,6 @@ int mwifiex_send_tdls_action_frame(struct mwifiex_private *priv, const u8 *peer,
if (mwifiex_construct_tdls_action_frame(priv, peer, action_code,
dialog_token, status_code,
skb)) {
- dev_kfree_skb_any(skb);
return -EINVAL;
}

--
2.25.1

2021-04-13 22:16:08

by Brian Norris

Subject: Re: [PATCH] wireless/marvell/mwifiex: Fix a double free in mwifiex_send_tdls_action_frame

Hi,

On Wed, Apr 14, 2021 at 12:08:32AM +0800, [email protected] wrote:
>
> Hi,
> maintianers.
>
> Sorry to disturb you, but this patch seems to be missed more than two weeks.
> Could you help to review this patch? I am sure it won't take you much time.

You might take a look here:
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#checking_state_of_patches_from_patchwork
https://patchwork.kernel.org/project/linux-wireless/list/

Two weeks is not unheard of for waiting.

Anyway, you *did* succeed in catching my attention today, so I'll give
you a review, below:

> > -----原始邮件-----
> > 发件人: "Lv Yunlong" <[email protected]>
> > 发送时间: 2021-03-29 19:24:35 (星期一)
> > 收件人: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
> > 抄送: [email protected], [email protected], [email protected], "Lv Yunlong" <[email protected]>
> > 主题: [PATCH] wireless/marvell/mwifiex: Fix a double free in mwifiex_send_tdls_action_frame
> >
> > In mwifiex_send_tdls_action_frame, it calls mwifiex_construct_tdls_action_frame
> > (..,skb). The skb will be freed in mwifiex_construct_tdls_action_frame() when
> > it is failed. But when mwifiex_construct_tdls_action_frame() returns error,
> > the skb will be freed in the second time by dev_kfree_skb_any(skb).
> >
> > My patch removes the redundant dev_kfree_skb_any(skb) when
> > mwifiex_construct_tdls_action_frame() failed.
> >
> > Fixes: b23bce2965680 ("mwifiex: add tdls_mgmt handler support")
> > Signed-off-by: Lv Yunlong <[email protected]>
> > ---
> > drivers/net/wireless/marvell/mwifiex/tdls.c | 1 -
> > 1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/net/wireless/marvell/mwifiex/tdls.c b/drivers/net/wireless/marvell/mwifiex/tdls.c
> > index 97bb87c3676b..8d4d0a9cf6ac 100644
> > --- a/drivers/net/wireless/marvell/mwifiex/tdls.c
> > +++ b/drivers/net/wireless/marvell/mwifiex/tdls.c
> > @@ -856,7 +856,6 @@ int mwifiex_send_tdls_action_frame(struct mwifiex_private *priv, const u8 *peer,
> > if (mwifiex_construct_tdls_action_frame(priv, peer, action_code,
> > dialog_token, status_code,
> > skb)) {
> > - dev_kfree_skb_any(skb);

Good catch, and this looks correct for most cases, but I'll note that
you missed one issue: mwifiex_construct_tdls_action_frame() has a
default/error case ("Unknown TDLS action frame type") which does *not*
free this SKB, so you should patch that up at the same time. Otherwise,
you're trading a double-free for a potential memory leak.

With that fixed:

Reviewed-by: Brian Norris <[email protected]>

Thanks.

> > return -EINVAL;
> > }
> >
> > --
> > 2.25.1
> >