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 AB5152572 for ; Tue, 18 Apr 2023 12:47:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3158CC433EF; Tue, 18 Apr 2023 12:47:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681822048; bh=zr5LTGDtV+oczzGvn6qOkrO6MGsv74CWL+RACJzmASk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PHcFqOCFXMTPOc36axcjqyqXc7RiYHNVlbwu7WpR2l3W/aQdLBrlawIOa08K5Lkz0 5hWqFi23jHsMunkLVzORbr7MZWMSzVRj5ch2XL1whyD/uS2ZfjPxaO8qUCzzXYq4NS iEOwhLkqzDiFoLcinmy9Auimr70GJ/uHnMPrVSfU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Waiman Long , Tejun Heo Subject: [PATCH 6.1 112/134] cgroup/cpuset: Fix partition roots cpuset.cpus update bug Date: Tue, 18 Apr 2023 14:22:48 +0200 Message-Id: <20230418120317.089478368@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120313.001025904@linuxfoundation.org> References: <20230418120313.001025904@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Waiman Long commit 292fd843de26c551856e66faf134512c52dd78b4 upstream. It was found that commit 7a2127e66a00 ("cpuset: Call set_cpus_allowed_ptr() with appropriate mask for task") introduced a bug that corrupted "cpuset.cpus" of a partition root when it was updated. It is because the tmp->new_cpus field of the passed tmp parameter of update_parent_subparts_cpumask() should not be used at all as it contains important cpumask data that should not be overwritten. Fix it by using tmp->addmask instead. Also update update_cpumask() to make sure that trialcs->cpu_allowed will not be corrupted until it is no longer needed. Fixes: 7a2127e66a00 ("cpuset: Call set_cpus_allowed_ptr() with appropriate mask for task") Signed-off-by: Waiman Long Cc: stable@vger.kernel.org # v6.2+ Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- kernel/cgroup/cpuset.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1509,7 +1509,7 @@ static int update_parent_subparts_cpumas spin_unlock_irq(&callback_lock); if (adding || deleting) - update_tasks_cpumask(parent, tmp->new_cpus); + update_tasks_cpumask(parent, tmp->addmask); /* * Set or clear CS_SCHED_LOAD_BALANCE when partcmd_update, if necessary. @@ -1766,10 +1766,13 @@ static int update_cpumask(struct cpuset /* * Use the cpumasks in trialcs for tmpmasks when they are pointers * to allocated cpumasks. + * + * Note that update_parent_subparts_cpumask() uses only addmask & + * delmask, but not new_cpus. */ tmp.addmask = trialcs->subparts_cpus; tmp.delmask = trialcs->effective_cpus; - tmp.new_cpus = trialcs->cpus_allowed; + tmp.new_cpus = NULL; #endif retval = validate_change(cs, trialcs); @@ -1834,6 +1837,11 @@ static int update_cpumask(struct cpuset } spin_unlock_irq(&callback_lock); +#ifdef CONFIG_CPUMASK_OFFSTACK + /* Now trialcs->cpus_allowed is available */ + tmp.new_cpus = trialcs->cpus_allowed; +#endif + /* effective_cpus will be updated here */ update_cpumasks_hier(cs, &tmp, false);