Re: [PATCH] mac80211: fix mesh forwarding when ratelimited too

From: Johannes Berg
Date: Thu Dec 30 2010 - 03:53:22 EST


On Thu, 2010-12-30 at 02:01 -0600, Milton Miller wrote:
> Commit b51aff057c9d0ef6c529dc25fd9f775faf7b6c63 said:
>
> Under memory pressure, the mac80211 mesh code
> may helpfully print a message that it failed
> to clone a mesh frame and then will proceed
> to crash trying to use it anyway. Fix that.
>
> Avoid the reference whenever the frame copy is unsuccessful
> regardless of the debug message being suppressed or printed.
>
> Cc: stable@xxxxxxxxxx [2.6.27+]
> Signed-off-by: Milton Miller <miltonm@xxxxxxx>
> ---
> I chose a seperate if vs nesting the ratelimit check to avoid shifting
> the printk further to the right.
>
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index b01e467..e98668f 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -1788,11 +1788,11 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
>
> fwd_skb = skb_copy(skb, GFP_ATOMIC);
>
> - if (!fwd_skb && net_ratelimit()) {
> + if (!fwd_skb && net_ratelimit())
> printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
> sdata->name);
> + if (!fwd_skb)
> goto out;
> - }

Oops, good catch! Thanks.

johannes

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/