Re: [PATCH net v5 2/2] octeon_ep: Add SKB allocation failures handling in __octep_oq_process_rx()

[Jacob Keller <jacob.e.keller@intel.com>]

On 10/17/2024 3:06 AM, Aleksandr Mishin wrote:
> build_skb() returns NULL in case of a memory allocation failure so handle
> it inside __octep_oq_process_rx() to avoid NULL pointer dereference.
> 
> __octep_oq_process_rx() is called during NAPI polling by the driver. If
> skb allocation fails, keep on pulling packets out of the Rx DMA queue: we
> shouldn't break the polling immediately and thus falsely indicate to the
> octep_napi_poll() that the Rx pressure is going down. As there is no
> associated skb in this case, don't process the packets and don't push them
> up the network stack - they are skipped.
> 
> Helper function is implemented to unmmap/flush all the fragment buffers
> used by the dropped packet. 'alloc_failures' counter is incremented to
> mark the skb allocation error in driver statistics.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 37d79d059606 ("octeon_ep: add Tx/Rx processing and interrupt support")
> Suggested-by: Paolo Abeni <pabeni@redhat.com>
> Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
> ---
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>