From: Paolo Abeni <pabeni@redhat.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>, netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org,
edumazet@google.com
Subject: Re: [PATCH net 1/6] netfilter: nf_tables: report use refcount overflow
Date: Thu, 06 Jul 2023 11:01:42 +0200 [thread overview]
Message-ID: <8c98394f6d399b4e725521f8d9fe9788f7fe3784.camel@redhat.com> (raw)
In-Reply-To: <20230705230406.52201-2-pablo@netfilter.org>
On Thu, 2023-07-06 at 01:04 +0200, Pablo Neira Ayuso wrote:
> Overflow use refcount checks are not complete.
>
> Add helper function to deal with object reference counter tracking.
> Report -EMFILE in case UINT_MAX is reached.
>
> nft_use_dec() splats in case that reference counter underflows,
> which should not ever happen.
For the records, I also once had the need for an non atomic reference
counters implementing sanity checks on underflows/overflows. I resorted
to use plain refcount_t, since the atomic op overhead was not
noticeable in my use-case.
[not blocking this series, just thinking aloud] I'm wondering if a
generic, non-atomic refcounter infra could be useful?
Cheers,
Paolo
next prev parent reply other threads:[~2023-07-06 9:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-05 23:04 [PATCH net 0/6] Netfilter fixes for net Pablo Neira Ayuso
2023-07-05 23:04 ` [PATCH net 1/6] netfilter: nf_tables: report use refcount overflow Pablo Neira Ayuso
2023-07-06 9:01 ` Paolo Abeni [this message]
2023-07-06 9:20 ` patchwork-bot+netdevbpf
2023-07-05 23:04 ` [PATCH net 2/6] netfilter: conntrack: gre: don't set assured flag for clash entries Pablo Neira Ayuso
2023-07-05 23:04 ` [PATCH net 3/6] netfilter: conntrack: Avoid nf_ct_helper_hash uses after free Pablo Neira Ayuso
2023-07-05 23:04 ` [PATCH net 4/6] netfilter: conntrack: don't fold port numbers into addresses before hashing Pablo Neira Ayuso
2023-07-05 23:04 ` [PATCH net 5/6] netfilter: nf_tables: do not ignore genmask when looking up chain by id Pablo Neira Ayuso
2023-07-05 23:04 ` [PATCH net 6/6] netfilter: nf_tables: prevent OOB access in nft_byteorder_eval Pablo Neira Ayuso
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