From: Florian Westphal <fw@strlen.de>
To: David Dull <monderasdor@gmail.com>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [PATCH] netfilter: guard option walkers against 1-byte tail reads
Date: Sat, 7 Mar 2026 19:34:10 +0100 [thread overview]
Message-ID: <aaxvov0E_yR6SvcJ@strlen.de> (raw)
In-Reply-To: <20260307182621.1315-1-monderasdor@gmail.com>
David Dull <monderasdor@gmail.com> wrote:
> When the last byte of options is a non-single-byte option kind, walkers
> that advance with i += op[i + 1] ? : 1 can read op[i + 1] past the end
> of the option area.
>
> Add an explicit i == optlen - 1 check before dereferencing op[i + 1]
> in xt_tcpudp and xt_dccp option walkers.
Fixes: 2e4e6a17af35 ("[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables")
next prev parent reply other threads:[~2026-03-07 18:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-07 18:26 [PATCH] netfilter: guard option walkers against 1-byte tail reads David Dull
2026-03-07 18:34 ` Florian Westphal [this message]
2026-03-07 18:45 ` [PATCH v2] " David Dull
2026-03-08 11:11 ` Pablo Neira Ayuso
2026-03-08 15:52 ` [PATCH v3] " David Dull
2026-03-08 17:05 ` Pablo Neira Ayuso
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