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 D9C76426435; Tue, 1 Sep 2026 17:32:47 +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=1788283968; cv=none; b=PHqVlh1mZcarVX6GkbZqUTVaoFXzGBI0gTaKavnqBIv51/SN1zKqX1egubNEZC1V/FKOQ75O1JNpQpVBzYehKoFU2XZvqQ9KsVUM1pDLatT7HnIx07Td9S53Iu4lFMm3tXZC79DGIL+PBnoE2GAX13n48UPJH6ErEDBzBkjsaAg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788283968; c=relaxed/simple; bh=Rr9DcnzGfDniKnZu6uk7mKcWGKvoO3lnrvTegD8f/CI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sgE0zrBSKKpBrOHVL1kr3ejkDQci6rEFM6h9XzLGeqIaLvniVwAKitIB224Fb2Z8eKFhrksk9j4L1yjMmHHTKQE+vFPa64xkIXy7eWOGOcSF5d6mBNGC7Va019D0fkvRMmzWrJnCYws2q/PJVq7C1ZvOhBZYep/YcoSP7o+o6dI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W8deQ515; 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="W8deQ515" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66BE31F000E9; Tue, 1 Sep 2026 17:32:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788283967; bh=XoQplwBUo06+4jP2MEzgMvoeNOiIgnXEwceMs0KQWlw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=W8deQ515tV42TIWvnAqfpAs96P3VW2gXrOcbXv0Q6pbPqf6oeFXSiI2ZS+0vP06JM e2EnOhNgJeMyLN8hTP/p0E0qxrHlqIZSEMGP9dQwkawCce5YDaEPC2Zthk4plcW58G G98+BPggJbSN/NKesSKo8AefkhJNXvbRYgTRal5NXvVmMVUehaVnx0UwFY4YZrKd86 JHEMM94tyVzoxe82SwV9BgtgNvCVDmcNJOpl9P8CAW+zQDeC/7Nv4z1x4XWpc4NA5P ePDBvtbE2Pa4qx8EWafNKDQvzLyakSerpD7+2C9ARXDBYORhzL1jukMagmpgvT9RdB 9EEcdO3tTJJkg== Message-ID: <3d8ef804-efc1-46c7-bbb4-f1a6c26fed8b@kernel.org> Date: Tue, 1 Sep 2026 19:32:34 +0200 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH net] net/ipv6: don't route packets with unknown source address Content-Language: fr To: =?UTF-8?B?w43DsWlnbyBIdWd1ZXQ=?= , David Ahern , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Neal Cardwell , Ido Schimmel , Pablo Neira Ayuso , Florian Westphal , Willem de Bruijn Cc: Simon Horman , Kuniyuki Iwashima , Phil Sutter , Daniel Borkmann , Fernando Fernandez Mancera , Alexei Starovoitov , Junseo Lim , Leon Hwang , Xuanqiang Luo , Willem de Bruijn , Kees Cook , Qi Tang , Jeff Layton , Joe Damato , Breno Leitao , Li RongQing , "open list:VRF" , open list , "open list:NETFILTER" , "open list:NETFILTER" , "open list:BPF [MISC] :Keyword:(?:b|_)bpf(?:b|_)" References: <20260901115021.50057-1-ihuguet@riseup.net> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: <20260901115021.50057-1-ihuguet@riseup.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Íñigo, On 01/09/2026 13:50, Íñigo Huguet wrote: > Don't allow routing packets with a source address that is not configured > in the host. Allow it only in certain cases like when using a > transparent socket, by setting the ANYSRC flag in flowi_flags. > > Until now, it was possible to send such a packet if a route can be found > in the routing table for it. For example: > 1. Configure an address 1:2::3:4/64 and a static route 1:2::/64 > 2. Establish a TCP connection to 1:2::3:4 > 3. Remove the address from the interface, but keep the route. > 4. Packets are still sent out by the TCP connection because of > the static route. No incoming packets are accepted, though. > > This patch prevents the outgoing packets to be sent in normal > circumnstances. > > This aligns the behaviour with the IPv4 stack. To determine the places > where the ANYSRC needs to be set, I set the flag in the same places as > the IPv4 stack does. > > Apart from consolidating the behaviour of both stacks, there is a more > important reason why this is needed. RFC 4862 states that "an invalid > address MUST NOT be used as the source address of outbound packets". > Therefore, sending packets with a source address considered "invalid", > like an expired address, is disallowed. Thank you for looking at this, but I think your patch is causing multiple KASAN warnings, e.g. https://netdev-ctrl.bots.linux.dev/logs/vmksft/net-extra-dbg/results/804584/24-connect-deny-ipv6/stderr And a few more, see: https://netdev.bots.linux.dev/branch_deltas/net-next-2026-09-01--15-01.html Cheers, Matt -- pw-bot: cr