From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 3CC9328725F for ; Mon, 5 Jan 2026 16:43:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767631437; cv=none; b=WlrCI8P9JanHr1lGgnMmOngCbIQWRL4nZer0Ah+spgc1Duho8Vv+M7IQqLhg8VVf2ZucrM0RwYj2krPLk+85F5DpFJaCrEyY1Qodz9ZDz2epM9RsdnN8ZhkXI3XeJ7n+6c9ApALr6sJBT6+QXrTrQVbV5Cj/gMg8Cn/xA+vClqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767631437; c=relaxed/simple; bh=V2RcMFWNxHXpx7Cbk1wLqeq5HUPDZY2CLps3fwdMAtY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=VPFTpmRtPLYwwW8L52BdtjBTqHc6aixCRzRhKKZSpO8SOlL9KCWWCsSeJ2JArYfJyepVkcx1yUCs7VRHP3ZGhGJECodZAcx3oLcrPqn1PqFnIsEQjmHivPHkdVB69ztvDschVsi/q5XuvHZ4eF5mO0nKWe7ygB1vmhC0YNybrcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SDbhuYD+; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=BfTT5jWW; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SDbhuYD+"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="BfTT5jWW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767631434; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=V2RcMFWNxHXpx7Cbk1wLqeq5HUPDZY2CLps3fwdMAtY=; b=SDbhuYD+zHAUYkGSI0OlEWCSzGeUpnfl+AiymGcVacGPTMAobII4Qs2vwmFG0ymq34KyTs Hz95amezKtI5AQeU9Ribddsw666lmJjh+prizyutxZKbyScT2/mD9LVXENGbCnUhgLla37 x0IYEBWm9o2PBcJPeKpe78lGzIvM6PA= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-449-n172sz19Pn2iY242UqoD7A-1; Mon, 05 Jan 2026 11:43:53 -0500 X-MC-Unique: n172sz19Pn2iY242UqoD7A-1 X-Mimecast-MFC-AGG-ID: n172sz19Pn2iY242UqoD7A_1767631432 Received: by mail-ed1-f72.google.com with SMTP id 4fb4d7f45d1cf-64ba13b492aso99644a12.1 for ; Mon, 05 Jan 2026 08:43:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1767631432; x=1768236232; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:from:to:cc:subject:date:message-id :reply-to; bh=V2RcMFWNxHXpx7Cbk1wLqeq5HUPDZY2CLps3fwdMAtY=; b=BfTT5jWWW9XcWvj2mHWxy95/dLJmljmH225nTzmf9u01uoo+9HWhIKFHWalLCZq+Oo XXcCsC3sMvGWfXDw1G3idF6qakzRnpWdKQn7MszfbcmtxleLFQVdi359RqvqUmtqOWeM Zdmn5A9D/SZKOYilVIQWPq4Y+tzG6GtgU0+/OFC5dN6efNxIuXhLEopShYsuDXWUqwJB kaRjDqLsHMx7CK41m8C7oa2wLcez1cYUFD1nqeG3pmjGCi46tanzzjphD3bXCqvsfqNt udlNwWdAiOVT35KkUM0bus6VfS9XUXeL+u0u0dpkKKOegkhFVnUhuWrki729FpconX2d 7HjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767631432; x=1768236232; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=V2RcMFWNxHXpx7Cbk1wLqeq5HUPDZY2CLps3fwdMAtY=; b=OivJJ+uETCculyKt0bVptP87Ynk9W5tObPYEgI06ie1OvqjRSH0CuillL0tFwdKQkg niVE5TTnGln0KO9XhOnH3APZ6axNGVdcXUn/sFwhMCT9HrMJubdkfp+vnfRuXe47qMuO hF6bY468C4P6QlTm4C0L8R+2ONPdOX9Z4WcvyLkjea8FCyG8XbTijaZd9jp8vIcLoHEC RC7b7oxJwfRALeO5w2LAklrOS2Wx1YZW+TdBrIcGV2ewsAehnkNjCc8QCYosMgC16isz RV316OFIW5wQ9LlCHV1yWz21nm4/hdX2Q1dZql23akFbqvbnSsJ2Gd7WwB7HhCPIMBWE 3zxA== X-Forwarded-Encrypted: i=1; AJvYcCXfQpIHRctDHyEFTTffvNe12OD9JgEOG0LtBa7cFqjGTsqSQZlslXnjG0BXdsbleyn2pWsEOwT6M57n6O0=@vger.kernel.org X-Gm-Message-State: AOJu0YwpgUsFHRfRoYtbLIQ0QZVxZKiEkIir8z++0/ZjuB3QLv521HQC cWSTfgNqAcCKuy2Ad4rq+ASeH0B3DRzMv3taoZX2dsg/bG9mvEnVFTG4dglHXHKEIfzuAAb1Zm6 XH675FbrVGunL2NrmGn4PD0D69hNfH/KZCBvLslBq7P0Gyclb3jZoL4XDaOeew+nNfQ== X-Gm-Gg: AY/fxX4dzuvxC81/3vvObw5d3YSd7Te5awmEUX/xZL/wrHJpRfeHsE28DS0vhvELcUD 6Nhn+m4zKmfzREBq3HuxexxsvGLY1Tn1txyS5mRge5W4Tr9979YVRK9sxx2iRtxh15Sq+48d+38 LPIW35qpApV18HH91sIIBf0IOsJhO+lt0NPjUbYgETqjVRa68tod2F0x6/OgXSnFSpeBeQLo8iB O49FWbrweyj+4js27wdL3PxWsSrSbyVtSNTv+GG+XYaPIGtNcna7YhioSq7C/mHv8NRNV1mvRGS lgBrIuI5GxUZE3F1LQrfgHbh24uA7JnIoh5jpsDdA3d9t2gmqLkTycmW4/4ycM8qjemf4AxPOGy VPpwye9r7D/nKUu+KriCr3ZpwAwFf1lq6e0w8 X-Received: by 2002:a05:6402:4414:b0:64b:ea6b:a884 with SMTP id 4fb4d7f45d1cf-65079561d9amr39808a12.17.1767631431874; Mon, 05 Jan 2026 08:43:51 -0800 (PST) X-Google-Smtp-Source: AGHT+IH5+CYTAwrLc8azSOHqieZ/AYKr+pOh1WCTsnwOkUqmz4srueS6d/oRRO9LBMmPRJORe96YbQ== X-Received: by 2002:a05:6402:4414:b0:64b:ea6b:a884 with SMTP id 4fb4d7f45d1cf-65079561d9amr39766a12.17.1767631431378; Mon, 05 Jan 2026 08:43:51 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk (alrua-x1.borgediget.toke.dk. [2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-6507618cc31sm222081a12.24.2026.01.05.08.43.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jan 2026 08:43:50 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 18D1C407EDE; Mon, 05 Jan 2026 17:43:50 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: KaFai Wan , ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, hawk@kernel.org, shuah@kernel.org, aleksander.lobakin@intel.com, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Yinhao Hu , Kaiyan Mei , Dongliang Mu Subject: Re: [PATCH bpf-next 1/2] bpf, test_run: Fix user-memory-access vulnerability for LIVE_FRAMES In-Reply-To: <38dd70d77f8207395206564063b0a1a07dd1c6e7.camel@linux.dev> References: <20260104162350.347403-1-kafai.wan@linux.dev> <20260104162350.347403-2-kafai.wan@linux.dev> <87y0mc5obp.fsf@toke.dk> <38dd70d77f8207395206564063b0a1a07dd1c6e7.camel@linux.dev> X-Clacks-Overhead: GNU Terry Pratchett Date: Mon, 05 Jan 2026 17:43:50 +0100 Message-ID: <87ms2s57sp.fsf@toke.dk> Precedence: bulk X-Mailing-List: linux-kernel@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 KaFai Wan writes: > On Mon, 2026-01-05 at 11:46 +0100, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> KaFai Wan writes: >>=20 >> > This fix reverts to the original version and ensures data_hard_start >> > correctly points to the xdp_frame structure, eliminating the security >> > risk. >>=20 >> This is wrong. We should just be checking the meta_len on input to >> account for the size of xdp_frame. I'll send a patch. > > Current version the actual limit of the max input meta_len for live frame= s is=20 > XDP_PACKET_HEADROOM - sizeof(struct xdp_frame), not > XDP_PACKET_HEADROOM. By "current version", you mean the patch I sent[0], right? If so, that was deliberate: the stack limits the maximum data_meta size to XDP_PACKET_HEADROOM - sizeof(struct xdp_frame), so there's no reason not to do the same for bpf_prog_run(). And some chance that diverging here will end up surfacing other bugs down the line. -Toke [0] https://lore.kernel.org/r/20260105114747.1358750-1-toke@redhat.com