From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-171.mta1.migadu.com [95.215.58.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E27C7413799 for ; Wed, 2 Sep 2026 09:29:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788341393; cv=none; b=mI3g8S1dNw2LCmTTPzu+lkNx4xpi+3AFLJK9J/qConcNH4muQevRAsSRgSj2Yah4nSiyvAGWVMknSu+UlfbK6kHQ9plc2t2AruNq8KMvdWW2I/HrEfEIJB1+2Uzi/H9DqSSEWR5+SNG9FBgKe/Symw0Tw2fTsY0EoM84IYgFdQg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788341393; c=relaxed/simple; bh=nXVAMVCk2SAZDGSV63lvGul1vVa5/XzRCxj6a3/JecU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WeqEGh1RiVRvqVzFnS0PaYPSALUTErJ2dqrSSbo+KkOIYZ+X60dpW5xlCiJyUyrLV6CMOg0c+W9F7xV9elqr1/y357ADDJBSbSZGNeU8K5Of61ODvqVp/O57lu+m/Ydb/CfeDgbCEp5jy13ltzW7bKAUJNt0NvnGDVDSIm3GEe0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=WG8hyeEj; arc=none smtp.client-ip=95.215.58.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="WG8hyeEj" X-Envelope-To: netdev@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=nXVAMVCk2SAZDGSV63lvGul1vVa5/XzRCxj6a3/JecU=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788341389; v=1; x=1788946189; b=WG8hyeEjwcmvHkOaUtVT5T1YI6XTrix5ByzOkY+6wGZlrtZcG4KmrxotmVGlmdX4/1xJ4NdR aTF92Pt5o4o5QmCHPbhtjfTQlOviJETQO11NphOt5z/4XtUQ0lxV+HKdPlMdkeKPeVvlgdJqKec Nb8UsOvMZb94Y8U9ecJhIZts= X-Envelope-To: netdev@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id aa64bcd72e854232; Wed, 02 Sep 2026 09:29:49 +0000 X-Mizu-Trace-ID: aa64bcd72e854232 X-Migadu-Flow: FLOW_OUT Message-ID: <84b011a3-7662-4f6e-ad4d-6bf81d2e1b30@linux.dev> Date: Wed, 2 Sep 2026 17:29:39 +0800 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v3] ip: validate options before echoing them To: Daehyeon Ko <4ncienth@gmail.com>, netdev@vger.kernel.org Cc: David Ahern , Ido Schimmel , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , linux-kernel@vger.kernel.org References: <20260902055802.3724915-1-4ncienth@gmail.com> From: Jiayuan Chen In-Reply-To: <20260902055802.3724915-1-4ncienth@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit on 9/2/26 1:58 PM, Daehyeon Ko wrote: > IPv4 option metadata stores absolute offsets from the network header in the > skb control block. That metadata is only safe to use while it still > describes the header at skb_network_header(). > > This invariant can be broken in more than one way. An IPv6 UDP packet can > remain queued while IPV6_ADDRFORM converts its socket to IPv4, after which For IPV6_ADDRFORM, we already reject this operation if outgoing ipv6 packets still exist. case IPV6_ADDRFORM: ...... if (sk->sk_protocol == IPPROTO_UDP) { if (udp_sk(sk)->pending == AF_INET6) { retv = -EBUSY; break; } May be we can also reject this operationif ipv6 skbs still exist in read/recv queue ?