From nobody Thu Feb 12 06:33:18 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 08601EE6457 for ; Fri, 15 Sep 2023 12:06:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234576AbjIOMGV (ORCPT ); Fri, 15 Sep 2023 08:06:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234630AbjIOMGO (ORCPT ); Fri, 15 Sep 2023 08:06:14 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B16BD2D6A; Fri, 15 Sep 2023 05:03:30 -0700 (PDT) Date: Fri, 15 Sep 2023 12:03:28 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1694779409; 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=GLBD5gHegkqpwAJ7rP50B51wP7vUAAVgVBjCLxzMmJo=; b=sgZwc2bFfSloZs4gzJcl/JUZN1YJPsM/MV6IrJ0kfSW94XJlIB4JPD6e1lrbjUutTK78nz SevHBwHaMa9FVvlJazukJN6wr547rLTJSuTJxxX9fHp9cTZX2otEUvKEEBSVqfoKw/nQR+ TGRnLFS2sOeiyc49daxs/8qw7Qm3bEY/SEg8ixn6VEc2AcH4QWPHI3vku5BJpyjtX4XACL 2eRVGPR4ifjscGaDaooaRQQNDwguNWMioWGvUykEcfzWgVoywJx5Y1UlUEgDkDI2OuJ0Kn siowSqSHkQlhkdLEMaImymLjba6ani0X95NnnHDiqPfaiw+37tAXeqN4isTX0A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1694779409; 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=GLBD5gHegkqpwAJ7rP50B51wP7vUAAVgVBjCLxzMmJo=; b=0C9QESB34lY/HC3w0wc9B6AiXKhmRaTrsXFY+CczPObmf8t+0sJYqRBarnEgbEfCOCVzhJ j3bEUv9ExYVPLaDA== From: "tip-bot2 for Yury Norov" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched/topology: Fix sched_numa_find_nth_cpu() in CPU-less case Cc: Yicong Yang , Guenter Roeck , Yury Norov , Ingo Molnar , Mel Gorman , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20230819141239.287290-4-yury.norov@gmail.com> References: <20230819141239.287290-4-yury.norov@gmail.com> MIME-Version: 1.0 Message-ID: <169477940847.27769.15320684535553252937.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/core branch of tip: Commit-ID: 617f2c38cb5ce60226042081c09e2ee3a90d03f8 Gitweb: https://git.kernel.org/tip/617f2c38cb5ce60226042081c09e2ee3a= 90d03f8 Author: Yury Norov AuthorDate: Sat, 19 Aug 2023 07:12:35 -07:00 Committer: Ingo Molnar CommitterDate: Fri, 15 Sep 2023 13:48:10 +02:00 sched/topology: Fix sched_numa_find_nth_cpu() in CPU-less case When the node provided by user is CPU-less, corresponding record in sched_domains_numa_masks is not set. Trying to dereference it in the following code leads to kernel crash. To avoid it, start searching from the nearest node with CPUs. Fixes: cd7f55359c90 ("sched: add sched_numa_find_nth_cpu()") Reported-by: Yicong Yang Reported-by: Guenter Roeck Signed-off-by: Yury Norov Signed-off-by: Ingo Molnar Reviewed-by: Yicong Yang Cc: Mel Gorman Link: https://lore.kernel.org/r/20230819141239.287290-4-yury.norov@gmail.com Closes: https://lore.kernel.org/lkml/CAAH8bW8C5humYnfpW3y5ypwx0E-09A3QxFE1J= FzR66v+mO4XfA@mail.gmail.com/T/ Closes: https://lore.kernel.org/lkml/ZMHSNQfv39HN068m@yury-ThinkPad/T/#mf64= 31cb0b7f6f05193c41adeee444bc95bf2b1c4 --- kernel/sched/topology.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 05a5bc6..423d089 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -2122,12 +2122,16 @@ static int hop_cmp(const void *a, const void *b) */ int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node) { - struct __cmp_key k =3D { .cpus =3D cpus, .node =3D node, .cpu =3D cpu }; + struct __cmp_key k =3D { .cpus =3D cpus, .cpu =3D cpu }; struct cpumask ***hop_masks; int hop, ret =3D nr_cpu_ids; =20 rcu_read_lock(); =20 + /* CPU-less node entries are uninitialized in sched_domains_numa_masks */ + node =3D numa_nearest_node(node, N_CPU); + k.node =3D node; + k.masks =3D rcu_dereference(sched_domains_numa_masks); if (!k.masks) goto unlock;