Re: [PATCH] release oob skb in __consume_stateless_skb

[Philippe Gerum <rpm@xenomai.org>]

Brandon Ho <brandonho667@gmail.com> writes:

> When an oob-enabled driver receives packets, those skbs are allocated
> from oob pools. The evl core may leave some of these packets to the
> regular network stack for handling based on eBPF filter criteria.
> When the regular netstack eventually consumes these skbs via
> __consume_stateless_skb, the current implementation does not release
> them back to their oob pools, causing a resource leak.
>
> This patch adds a call to skb_release_oob() in __consume_stateless_skb
> to properly return oob skbs to their pools before the standard skb
> cleanup occurs.
>
> Target kernel series v6.12.y-cip-evl-rebase.
>
> Signed-off-by: Brandon Ho <brho@relativityspace.com>
> ---
>  kernel/evl/net/skb.c | 3 +++
>  net/core/skbuff.c    | 2 ++
>  2 files changed, 5 insertions(+)
>
> diff --git a/kernel/evl/net/skb.c b/kernel/evl/net/skb.c
> index 8efdca1da..302f79dfd 100644
> --- a/kernel/evl/net/skb.c
> +++ b/kernel/evl/net/skb.c
> @@ -55,6 +55,9 @@
>   *                                                -> free_skb_oob(skb)
>   *                        -> dev_kfree_skb(skb)
>   *                                -> consume_skb(skb) [1]
> + * 			  |
> + * 			    __consume_stateless_skb(skb)
> + * 						  -> free_skb_oob(skb)
>   */
>  
>  #define SKB_RECYCLING_THRESHOLD 32
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index e297781da..e08d0bc54 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -1645,6 +1645,8 @@ EXPORT_SYMBOL(consume_skb);
>  void __consume_stateless_skb(struct sk_buff *skb)
>  {
>  	trace_consume_skb(skb, __builtin_return_address(0));
> +	if (skb_release_oob(skb))
> +		return;
>  	skb_release_data(skb, SKB_CONSUMED);
>  	kfree_skbmem(skb);
>  }

Merged, thanks (split between dovetail and evl trees).

-- 
Philippe.