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 BFF4A8248B; Sun, 31 May 2026 04:53:57 +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=1780203238; cv=none; b=YwaKF15Gg2JlX9nK/8ZfPUoNui+QrIVli8j7FFjzH7YBCSW156XC438gPFHlJkj0dokVpLcO5TwxAeux4Of8vRa7QFr8JATUrDGadIU4woUuAegZKkkdcHjSrfpYyivpvLWaPj9ozvTGagfCM/DGpzF90RS58aMUW/m0hiJbRoM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780203238; c=relaxed/simple; bh=vukg6zkEBCeRat75eY80xfwwQusH0Jtuqltfqbs47i4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tpzIBIIe6cPTX95jVrkugvqu3wl/laq/qNG/w3g3YIEIIBAwi7OYwQOMUUT+oCP9oIdU+dTMSGtA+EOqTx4NKfDOMS+EG3nQZq7NJu3qZs5y8cIl54wXJODJnVw9Qbj66C4tGDbHF8n/xxWq13GsFb0NX/xwqJ+TBFTglA/qrrI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GBZ+FgED; 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="GBZ+FgED" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FC5E1F00893; Sun, 31 May 2026 04:53:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780203237; bh=vUuUkxwwEBS0oY6KW2ODS8yD/z/8/qNRxVwCoqJAHAU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=GBZ+FgED5GuCZqZfRmteD1GSo2YjdOnhX/7MNKctbfKukiPPCj9Y/xon+kOsYw0Iu SQLFjL09sJmrBbBEid8YyI6u6stMLCpHiviZoYeO7hzMji2NxFemL+Iqq7A6xGX+Je 3KryRJF7TTj4vUbnzyD7p+TQC4jwoixVqIvC+e7HEfk71YbfEIlZuHynz3KygLoJ40 CzguybW3x40IbXczu0nC2YbA5JyQ6VdWNW+u13rAceFx3SpgGY6uVvehJDDKR0dN4i 1GCt84YRMz2rfu4q8aGI4d4KEmFaoneskE2G1J5GZ5THN7LgWHMPYieIKd0HPi3fSo ZJ9mi3drHsEpw== Message-ID: Date: Sun, 31 May 2026 14:53:51 +1000 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH 6.6 113/186] netfilter: Exclude LEGACY TABLES on PREEMPT_RT. To: Greg Kroah-Hartman , Sasha Levin Cc: patches@lists.linux.dev, Sebastian Andrzej Siewior , Pablo Neira Ayuso , Florian Westphal , stable@vger.kernel.org References: <20260528194928.941004471@linuxfoundation.org> <20260528194931.993505304@linuxfoundation.org> From: Matthieu Baerts Content-Language: fr 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: <20260528194931.993505304@linuxfoundation.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Greg, Sasha, On 29/05/2026 05:49, Greg Kroah-Hartman wrote: > 6.6-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Pablo Neira Ayuso > > [ Upstream commit 9fce66583f06c212e95e4b76dd61d8432ffa56b6 ] > > The seqcount xt_recseq is used to synchronize the replacement of > xt_table::private in xt_replace_table() against all readers such as > ipt_do_table() > > To ensure that there is only one writer, the writing side disables > bottom halves. The sequence counter can be acquired recursively. Only the > first invocation modifies the sequence counter (signaling that a writer > is in progress) while the following (recursive) writer does not modify > the counter. > The lack of a proper locking mechanism for the sequence counter can lead > to live lock on PREEMPT_RT if the high prior reader preempts the > writer. Additionally if the per-CPU lock on PREEMPT_RT is removed from > local_bh_disable() then there is no synchronisation for the per-CPU > sequence counter. > > The affected code is "just" the legacy netfilter code which is replaced > by "netfilter tables". That code can be disabled without sacrificing > functionality because everything is provided by the newer > implementation. This will only requires the usage of the "-nft" tools > instead of the "-legacy" ones. > The long term plan is to remove the legacy code so lets accelerate the > progress. > > Relax dependencies on iptables legacy, replace select with depends on, > this should cause no harm to existing kernel configs and users can still > toggle IP{6}_NF_IPTABLES_LEGACY in any case. > Make EBTABLES_LEGACY, IPTABLES_LEGACY and ARPTABLES depend on > NETFILTER_XTABLES_LEGACY. Hide xt_recseq and its users, > xt_register_table() and xt_percpu_counter_alloc() behind > NETFILTER_XTABLES_LEGACY. Let NETFILTER_XTABLES_LEGACY depend on > !PREEMPT_RT. > > This will break selftest expecing the legacy options enabled and will be > addressed in a following patch. It looks like this last sentence is still valid: some net selftests are broken because the mentioned "following patch" -- commit 3c3ab65f00eb ("selftests: net: Enable legacy netfilter legacy options.") -- has not been backported in this 6.6 version. Same for v6.1 and v5.15. Do you mind adding it in v6.6, v6.1 and v5.15, please? Cheers, Matt -- Sponsored by the NGI0 Core fund.