Re: [PATCH bluetooth-next] ieee802154: 6lowpan: fix memory leak

[Alexander Aring <alex.aring@gmail.com>]

On Thu, Oct 22, 2015 at 12:11:27PM +0200, Alexander Aring wrote:
> Looking at current situation of memory management in 6lowpan receive
> function I detected some invalid handling. After calling
> lowpan_invoke_rx_handlers we will do a kfree_skb and then NET_RX_DROP on
> error handling. We don't do this before, also on
> skb_share_check/skb_unshare which might manipulate the reference
> counters.
> 
> After running some 'grep -r "dev_add_pack" net/' to look how others
> packet-layer receive callbacks works I detected that every subsystem do
> a kfree_skb, then NET_RX_DROP without calling skb functions which
> might manipulate the skb reference counters. This is the reason why we
> should do the same here like all others subsystems. I didn't find any
> documentation how the packet-layer receive callbacks handle NET_RX_DROP
> return values either.
> 
> This patch will add a kfree_skb, then NET_RX_DROP handling for the
> "trivial checks", in case of skb_share_check/skb_unshare the kfree_skb
> call will be done inside these functions.
> 
> Signed-off-by: Alexander Aring <alex.aring@gmail.com>
> ---
> References how other filesystem handle the callback:

s/filesystem/subsystems/

- Alex