From: Florian Westphal <fw@strlen.de>
To: Igor Garofano <igorgarofano@gmail.com>
Cc: pablo@netfilter.org, netfilter-devel@vger.kernel.org
Subject: Re: [SECURITY] nft_byteorder: incorrect u32* stride in 64-bit byteorder eval leading to firewall bypass
Date: Tue, 19 May 2026 20:34:01 +0200 [thread overview]
Message-ID: <agytGR61BMXsNSYq@strlen.de> (raw)
In-Reply-To: <CAOOOOYyfpwO7inyq2wXtpT0kY0s19-n4OZf2MCR62WRi7vzMMg@mail.gmail.com>
Igor Garofano <igorgarofano@gmail.com> wrote:
[ removed security@korg from CC ]
> A logic error in nft_byteorder_eval() causes incorrect byteorder conversion
> for 64-bit (size=8) operations in nftables. The source register is indexed
> using a u32* pointer (4-byte stride) while nft_reg_load64() reads 8 bytes,
> causing overlapping reads for any priv->len > 8. The result is that bytes
> are swapped from the wrong positions, leading to incorrect packet matching
> decisions.
Multi-stride is never used by nftables. This feature is unused and will
be removed:
https://patchwork.ozlabs.org/project/netfilter-devel/patch/20260512133617.8191-1-fw@strlen.de/
next parent reply other threads:[~2026-05-19 18:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAOOOOYyfpwO7inyq2wXtpT0kY0s19-n4OZf2MCR62WRi7vzMMg@mail.gmail.com>
2026-05-19 18:34 ` Florian Westphal [this message]
2026-05-20 12:13 ` [SECURITY] nft_byteorder: incorrect u32* stride in 64-bit byteorder eval leading to firewall bypass Greg KH
2026-05-20 12:17 ` Florian Westphal
2026-05-20 12:30 ` Greg KH
2026-05-23 14:39 ` Florian Westphal
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