From: Paolo Abeni <[email protected]>
Date: Fri, 8 Jun 2018 11:35:40 +0200
> After commit 6b229cf77d68 ("udp: add batching to udp_rmem_release()")
> the sk_rmem_alloc field does not measure exactly anymore the
> receive queue length, because we batch the rmem release. The issue
> is really apparent only after commit 0d4a6608f68c ("udp: do rmem bulk
> free even if the rx sk queue is empty"): the user space can easily
> check for an empty socket with not-0 queue length reported by the 'ss'
> tool or the procfs interface.
>
> We need to use a custom UDP helper to report the correct queue length,
> taking into account the forward allocation deficit.
>
> Reported-by: [email protected]
> Fixes: 6b229cf77d68 ("UDP: add batching to udp_rmem_release()")
> Signed-off-by: Paolo Abeni <[email protected]>
Applied and queued up for -stable, thanks.
