From nobody Mon Sep 15 03:53:23 2025 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 CCE18C46467 for ; Mon, 16 Jan 2023 09:14:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232165AbjAPJOg (ORCPT ); Mon, 16 Jan 2023 04:14:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232036AbjAPJOD (ORCPT ); Mon, 16 Jan 2023 04:14:03 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7320B1449A; Mon, 16 Jan 2023 01:13:49 -0800 (PST) Date: Mon, 16 Jan 2023 09:13:45 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1673860426; h=from:from:sender:sender:reply-to: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=8Qu6T2u5QqV7NYrJSK3GWcl2n1qPVAedbnw8VqSw0zo=; b=4t7EmSf+VAT3JNrKRA/Xvo3fty/takKYhaYWFobK2aVwWhkuDaHFzMQLMhiCD63n41JW77 ElsPWsZ3aKIZgzRTsmFFKewGuvjGrvet4LcKZrYWYTK97xrjtM8XxPAO3EM4eFrlO6yJ3A dy+0KWGJStK3MZzyPf+kgHQSkxtFJKY16FSDX6JS+t6hNIpOZ+7AqyoCzCmM18dxpz4H93 szwjvkh4ISNzZWaLq+kFGvK48/6MsENEQP200vDSJtacE7ED/pjymI5OwtI7wgKvXZCP0/ WFf/QHxMKUeEw+Zv8mBNoXZyJBPjUr7AavPTVzADYYtLNKhEGkJb/ICiKa13tA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1673860426; h=from:from:sender:sender:reply-to: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=8Qu6T2u5QqV7NYrJSK3GWcl2n1qPVAedbnw8VqSw0zo=; b=vgiajWa2Qz0uwLOlzJgiVMjvanUyYX1tuflE3rsXS7WrCqlmZR/mI8cectZUBoFyAUMCfe WpeVKQFp2ZNCoMCQ== From: "tip-bot2 for Waiman Long" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/urgent] sched/core: Fix NULL pointer access fault in sched_setaffinity() with non-SMP configs Cc: kernel test robot , Waiman Long , Ingo Molnar , Peter Zijlstra , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20230115193122.563036-1-longman@redhat.com> References: <20230115193122.563036-1-longman@redhat.com> MIME-Version: 1.0 Message-ID: <167386042602.4906.3347789446999182606.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/urgent branch of tip: Commit-ID: 5657c116783545fb49cd7004994c187128552b12 Gitweb: https://git.kernel.org/tip/5657c116783545fb49cd7004994c18712= 8552b12 Author: Waiman Long AuthorDate: Sun, 15 Jan 2023 14:31:22 -05:00 Committer: Ingo Molnar CommitterDate: Mon, 16 Jan 2023 10:07:25 +01:00 sched/core: Fix NULL pointer access fault in sched_setaffinity() with non-S= MP configs The kernel commit 9a5418bc48ba ("sched/core: Use kfree_rcu() in do_set_cpus_allowed()") introduces a bug for kernels built with non-SMP configs. Calling sched_setaffinity() on such a uniprocessor kernel will cause cpumask_copy() to be called with a NULL pointer leading to general protection fault. This is not really a problem in real use cases as there aren't that many uniprocessor kernel configs in use and calling sched_setaffinity() on such a uniprocessor system doesn't make sense. Fix this problem by making sure cpumask_copy() will not be called in such a case. Fixes: 9a5418bc48ba ("sched/core: Use kfree_rcu() in do_set_cpus_allowed()") Reported-by: kernel test robot Signed-off-by: Waiman Long Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/20230115193122.563036-1-longman@redhat.com --- kernel/sched/core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index bb1ee6d..e838feb 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8290,12 +8290,18 @@ long sched_setaffinity(pid_t pid, const struct cpum= ask *in_mask) if (retval) goto out_put_task; =20 + /* + * With non-SMP configs, user_cpus_ptr/user_mask isn't used and + * alloc_user_cpus_ptr() returns NULL. + */ user_mask =3D alloc_user_cpus_ptr(NUMA_NO_NODE); - if (IS_ENABLED(CONFIG_SMP) && !user_mask) { + if (user_mask) { + cpumask_copy(user_mask, in_mask); + } else if (IS_ENABLED(CONFIG_SMP)) { retval =3D -ENOMEM; goto out_put_task; } - cpumask_copy(user_mask, in_mask); + ac =3D (struct affinity_context){ .new_mask =3D in_mask, .user_mask =3D user_mask,