From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C9B3734CF9; Sun, 24 Aug 2025 06:03:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756015426; cv=none; b=KAybDpsSmRmK5Vb+E6TOW6z6DDYRwNEJnh76qAkceyIB/LT24ufVvZRdEn4UK97pAKVse1HYOCSB5e+MlHFAZMQtc4P8ZHP0Jx4EPxBf6lZIjGYBSiXM1ITKcSDU9hZBmNcwgeZZ8sYMkpcRm0GQJAhWNeN5wh32n4ZSDWZPdC4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756015426; c=relaxed/simple; bh=JM7Y8fZKei0R8TTZ4Y3zviWlvPivwcOmnRPos+eOBbo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=O1Uz8NrcCKs3eTGWQaN3D/BucjiUBhpMSoC4Qishz95Nnx8DWoGSk1r9Lkn0nJ6MioZXqSHyK8l5ASs3gY2egQbvHN+GYV1T8Iuft8QXoSHWM8Lz8DadPxclvYBC5oLtpeyrMqb6JBSysfCD+O1Sue5//QsFRc6utYia6a/JWxs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=l0v9wvQK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="l0v9wvQK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A92AAC4CEEB; Sun, 24 Aug 2025 06:03:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756015425; bh=JM7Y8fZKei0R8TTZ4Y3zviWlvPivwcOmnRPos+eOBbo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=l0v9wvQKMzpfpolvZ+Nyp/fgokA3VxbM5xzjzQyFGDIuiPo7AXg6jJkxTLi2NEagM Txblo9OnsWHEVk8Ko+hncV+WEpw3FglCnds7sIAkycNIVfHq7W+aDaTTfwNGrXIcNy OlmoBaYY5PovvlDurbB4pRSpMB9nAn2syOB9UFc0= Date: Sun, 24 Aug 2025 08:03:42 +0200 From: Greg Kroah-Hartman To: Chanho Min Cc: "David S . Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, gunho.lee@lge.com, stable@vger.kernel.org, Sasha Levin , Eric Dumazet , Jakub Kicinski Subject: Re: [PATCH] ipv6: mcast: extend RCU protection in igmp6_send() Message-ID: <2025082405-entomb-eligibly-c616@gregkh> References: <20250818092453.38281-1-chanho.min@lge.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=us-ascii Content-Disposition: inline In-Reply-To: <20250818092453.38281-1-chanho.min@lge.com> On Mon, Aug 18, 2025 at 06:24:53PM +0900, Chanho Min wrote: > From: Eric Dumazet > > [ Upstream commit 087c1faa594fa07a66933d750c0b2610aa1a2946 ] > > igmp6_send() can be called without RTNL or RCU being held. > > Extend RCU protection so that we can safely fetch the net pointer > and avoid a potential UAF. > > Note that we no longer can use sock_alloc_send_skb() because > ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep. > > Instead use alloc_skb() and charge the net->ipv6.igmp_sk > socket under RCU protection. > > Cc: stable@vger.kernel.org # 5.4 > Fixes: b8ad0cbc58f7 ("[NETNS][IPV6] mcast - handle several network namespace") > Signed-off-by: Eric Dumazet > Reviewed-by: David Ahern > Reviewed-by: Kuniyuki Iwashima > Link: https://patch.msgid.link/20250207135841.1948589-9-edumazet@google.com > [ chanho: Backports to v5.4.y. v5.4.y does not include > commit b4a11b2033b7(net: fix IPSTATS_MIB_OUTPKGS increment in OutForwDatagrams), > so IPSTATS_MIB_OUTREQUESTS was changed to IPSTATS_MIB_OUTPKGS defined as > 'OutRequests'. ] We can not take patches for only older kernel versions, as when you upgrade you would have a regression. Please send backports for all of the missing stable versions and we will be glad to queue them up. thanks, greg k-h