From nobody Sat Apr 11 06:40:08 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA106C00140 for ; Mon, 15 Aug 2022 14:21:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241569AbiHOOVw (ORCPT ); Mon, 15 Aug 2022 10:21:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231349AbiHOOVu (ORCPT ); Mon, 15 Aug 2022 10:21:50 -0400 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAEA1DFFF for ; Mon, 15 Aug 2022 07:21:49 -0700 (PDT) Received: by mail-pg1-x52e.google.com with SMTP id f65so6595056pgc.12 for ; Mon, 15 Aug 2022 07:21:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:subject:cc:to:from:from:to:cc; bh=6bzerbOi1tWbohdKcxG2J4gHSK0DtZlDBSqHyHqYooQ=; b=iPMTML2jz1BiYQfBqBGS3YYeXVtt15FuSdCGGuWOyT/67LoZPmxeP791Y7PUnYNPZx P9rktkoVrvEwWoi7SYGQqj4y7WAYmueSavo6TpCvt44JCduT2CUYGG1BamB2Cy9TcRYK jYt4r4S+D6hezp5gNLypnTmUsgvVgWCV5JPZQwMf8vFzEazCK8t6VjxBY6IIQCgyz/mp 01bfP9ONQGws96dCiD671x/PjQjxWh2ECUH2LNrUlOPubyP25fEdPX1co+oO/nh/Orwi Kpsva5TdSnpKoKKHhS+rTCupCXf7Ok3j5dNyYfPH0M92XUXkYUruZkeuVfvOKmk0aAud wKGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=6bzerbOi1tWbohdKcxG2J4gHSK0DtZlDBSqHyHqYooQ=; b=xFyubLq9fq1HRT0XWKYOfI6diwg+gdH7NnEAERnczbVsQK9f190SDQmb2pzQFMWNS/ DPJsTWJVjtiHNIvrkidUkC/Lvx0mJJmnRDWxb/pVUUATAzfj90kXI8YEpmAjAH3H1J1t LkuhinTO6LEwLvkyWCalWJEtmeeWVfrrkTSXEVOj+NEhm2q8R00X0BlNzqqIDSNr5qFm VQQDy+koxcKocgpxVPpMo/gxOSsJxJUoo/Q2mTIsm8B4BAcfIaKpko44MS5wv+8MuqQp Ay+yaFXk/WaTUffLxJyunF5pNUw7g7n54jhlsOD6PxcNZ4A8UgQIZ0FpNO2I7S2IOofg tgIQ== X-Gm-Message-State: ACgBeo1tgPGsW4F1didAOKhWKNtk1cxEeGXdHbtD47j0Gj2kglU18m+x ws+/I2/3tcGD6sg88Yv8hqc= X-Google-Smtp-Source: AA6agR7as9QSeTB5It8kcha2Bqy9jWQeAS4DTTUZyLZaU5nUjL/x4kinYNA2UfSEltgzYNQpwjx3WA== X-Received: by 2002:a63:d212:0:b0:41c:681b:e48a with SMTP id a18-20020a63d212000000b0041c681be48amr14006845pgg.79.1660573309521; Mon, 15 Aug 2022 07:21:49 -0700 (PDT) Received: from localhost.localdomain ([182.160.5.243]) by smtp.gmail.com with ESMTPSA id f18-20020a17090aa79200b001ef9659d711sm4517373pjq.48.2022.08.15.07.21.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Aug 2022 07:21:49 -0700 (PDT) From: Tuo Cao <91tuocao@gmail.com> To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org Cc: dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, 91tuocao@gmail.com Subject: [PATCH] sched: core: remove access_ok() before copy_to_user() Date: Mon, 15 Aug 2022 22:21:37 +0800 Message-Id: <20220815142137.29982-1-91tuocao@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" If usize > ksize, usize may be not valid and if(!access_ok()) will return -EFAULT. But ksize may be valid, copy_to_user() should be executed.And also, copy_to_user() will calls access_ok() to test whether a block of memory is a valid user space address. Signed-off-by: Tuo Cao <91tuocao@gmail.com> --- kernel/sched/core.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ee28253c9ac0..fe6a65a54626 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7975,9 +7975,6 @@ sched_attr_copy_to_user(struct sched_attr __user *uat= tr, { unsigned int ksize =3D sizeof(*kattr); =20 - if (!access_ok(uattr, usize)) - return -EFAULT; - /* * sched_getattr() ABI forwards and backwards compatibility: * --=20 2.17.1