From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1159274B3B for ; Mon, 25 May 2026 18:20:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779733213; cv=none; b=Ud1N+fOxgoUpnKwEErNjFMNe7zBq/WV8Kn9FJua9lVz6gFVPj3UPQWq8URR+GCDQ/mfq09dV/9KAA2XD86U/ARq/vwAqVflIg9gW3pR2ovQN1S5r/eQL9KqQjHDtnM/vk6hCaXqWoQ7j/NW8cgNr/FIC7PQQE7PGv8rgTjF8Mng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779733213; c=relaxed/simple; bh=Kn4dKo1Rheo90pPzWQDmQ12IwNK9PCSCeKh60AVviww=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Yl2Vv7Ggq2q8l7XmX713D1O5RfNxfOEOvpgdkRdP6OkX6ESR7THBujvvYngXK75kBkgZrmLnzSS5SCGwSugt1z879omfkwK1vYliRRh9C/ptg5E+1qGCRPPmOnX2u+dYwi4NPEYCQUZGSJ5XEKfxM+PjOcvhdBfLZYRu6u5YpJE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WB3ou9hw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WB3ou9hw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1BB31F000E9; Mon, 25 May 2026 18:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779733212; bh=Kn4dKo1Rheo90pPzWQDmQ12IwNK9PCSCeKh60AVviww=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=WB3ou9hwcJ4z/uKmDeY/t5Ipbt94KB/cAaBPMC9cv+eSleOQDJWFqeYxX2T9GDtC+ fk0wyGAykigvvvXGsZnOMvQTBALtf8CbHxxdhkJ+68ncGBrshueLKQL91g0tFJtrb9 2wrzp3lsDaP7p4ThFwB5XsRi660riJFViPmQaGMVAJ60nDepMA5R4w5qPLqWizfhBX 8xLjldEFBFE9b2caSU9lqr9RQ3bY4oCZhRFSy2tqngUzjpwmeH6aL/de1T07xEYTfL oADDq9ZZBwwpvOTBdV3tx6brHVQ24nAh/uCewQWxyZCfw6WP+eqUvQS0cBR1hlpDTg WJQnvmumj5wQA== Date: Mon, 25 May 2026 11:20:11 -0700 From: Jakub Kicinski To: Kuniyuki Iwashima Cc: Eric Dumazet , "David S . Miller" , Paolo Abeni , Simon Horman , Willem de Bruijn , netdev@vger.kernel.org, eric.dumazet@gmail.com, Damiano Melotti Subject: Re: [PATCH net] tunnels: do not assume transport header in iptunnel_pmtud_check_icmp() Message-ID: <20260525112011.38a93f49@kernel.org> In-Reply-To: References: <20260522115512.1519110-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sun, 24 May 2026 19:55:50 -0700 Kuniyuki Iwashima wrote: > On Fri, May 22, 2026 at 4:55=E2=80=AFAM Eric Dumazet wrote: > > > > In some cases, iptunnel_pmtud_check_icmp() can be called while > > skb transport header is not set. > > > > This triggers an out-of-bound access, because > > (typeof(skb->transport_header))~0U is 65535. > > > > Access the icmp header based on IPv4 network header, > > after making sure icmp->type is present in skb linear part. > > > > Note that iptunnel_pmtud_check_icmpv6()) is fine. > > > > Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly brid= ged IP packets") > > Reported-by: Damiano Melotti > > Signed-off-by: Eric Dumazet =20 >=20 > Reviewed-by: Kuniyuki Iwashima Are we okay with what sashiko is reporting? If it's legit it may be better to fix in one series