From: Simon Horman <horms@kernel.org>
To: Anders Grahn <anders.grahn@gmail.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>,
Jozsef Kadlecsik <kadlec@netfilter.org>,
Florian Westphal <fw@strlen.de>, Phil Sutter <phil@nwl.cc>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Anders Grahn <anders.grahn@westermo.com>,
linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org,
coreteam@netfilter.org, netdev@vger.kernel.org
Subject: Re: [PATCH] netfilter: nft_counter: Fix reset of counters on 32bit archs
Date: Mon, 15 Dec 2025 14:54:05 +0000 [thread overview]
Message-ID: <aUAhDdMGykBb2BOg@horms.kernel.org> (raw)
In-Reply-To: <20251215121258.843823-1-anders.grahn@westermo.com>
On Mon, Dec 15, 2025 at 01:12:57PM +0100, Anders Grahn wrote:
> nft_counter_reset() calls u64_stats_add() with a negative value to reset
> the counter. This will work on 64bit archs, hence the negative value
> added will wrap as a 64bit value which then can wrap the stat counter as
> well.
>
> On 32bit archs, the added negative value will wrap as a 32bit value and
> _not_ wrapping the stat counter properly. In most cases, this would just
> lead to a very large 32bit value being added to the stat counter.
>
> Fix by introducing u64_stats_sub().
>
> Fixes: 4a1d3acd6ea8 ("netfilter: nft_counter: Use u64_stats_t for statistic")
Nit: there is a minor mismatch in the subject of the Fixes tag and
git history: the trailing '.'
I would go for this. But perhaps it doesn't matter.
Fixes: 4a1d3acd6ea8 ("netfilter: nft_counter: Use u64_stats_t for statistic.")
> Signed-off-by: Anders Grahn <anders.grahn@westermo.com>
...
prev parent reply other threads:[~2025-12-15 14:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-15 12:12 [PATCH] netfilter: nft_counter: Fix reset of counters on 32bit archs Anders Grahn
2025-12-15 12:36 ` Florian Westphal
2025-12-15 13:53 ` David Laight
2025-12-15 14:01 ` Anders Grahn
2025-12-15 14:54 ` Simon Horman [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aUAhDdMGykBb2BOg@horms.kernel.org \
--to=horms@kernel.org \
--cc=anders.grahn@gmail.com \
--cc=anders.grahn@westermo.com \
--cc=bigeasy@linutronix.de \
--cc=coreteam@netfilter.org \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=fw@strlen.de \
--cc=kadlec@netfilter.org \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=pablo@netfilter.org \
--cc=phil@nwl.cc \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).