2017-04-24 11:41:03

by James Hughes

Subject: [PATCH v2] brcmfmac: Ensure pointer correctly set if skb data location changes

The incoming skb header may be resized if header space is
insufficient, which might change the data adddress in the skb.
Ensure that a cached pointer to that data is correctly set by
moving assignment to after any possible changes.

Signed-off-by: James Hughes <[email protected]>

Acked-by: Arend van Spriel <[email protected]>
---
Changes in v2

Moved the assignment below the len check - saves a few cycles
if the length check fails.


drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
index 5eaac13e2317..9b7c19a508ac 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
@@ -198,7 +198,7 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
int ret;
struct brcmf_if *ifp = netdev_priv(ndev);
struct brcmf_pub *drvr = ifp->drvr;
- struct ethhdr *eh = (struct ethhdr *)(skb->data);
+ struct ethhdr *eh;

brcmf_dbg(DATA, "Enter, bsscfgidx=%d\n", ifp->bsscfgidx);

@@ -236,6 +236,8 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
goto done;
}

+ eh = (struct ethhdr *)(skb->data);
+
if (eh->h_proto == htons(ETH_P_PAE))
atomic_inc(&ifp->pend_8021x_cnt);

--
2.11.0

2017-04-25 07:56:40

by Arend van Spriel

Subject: Re: [PATCH v2] brcmfmac: Ensure pointer correctly set if skb data location changes

On 24-4-2017 13:40, James Hughes wrote:
> The incoming skb header may be resized if header space is
> insufficient, which might change the data adddress in the skb.
> Ensure that a cached pointer to that data is correctly set by
> moving assignment to after any possible changes.

Hi Kalle,

This one should go on 4.12 queue as well.

Thanks,
Arend

> Signed-off-by: James Hughes <[email protected]>
>
> Acked-by: Arend van Spriel <[email protected]>
> ---

2017-04-26 09:04:49

by Kalle Valo

Subject: Re: [v2] brcmfmac: Ensure pointer correctly set if skb data location changes

James Hughes <[email protected]> wrote:
> The incoming skb header may be resized if header space is
> insufficient, which might change the data adddress in the skb.
> Ensure that a cached pointer to that data is correctly set by
> moving assignment to after any possible changes.
>
> Signed-off-by: James Hughes <[email protected]>
>
> Acked-by: Arend van Spriel <[email protected]>

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

455a1eb4654c brcmfmac: Ensure pointer correctly set if skb data location changes

--
https://patchwork.kernel.org/patch/9696045/

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