From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1CBE74F55B6; Wed, 30 Sep 2026 16:24:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790785461; cv=none; b=FSbzN8ZfYl/dlrt2jii9EWBBEgqkLwJndix50juwIVKZJvyoSszsSbNxwYwFwHmmAZKR/iwSnf+ThPHvEJz58K1agtAOYWAfl2BHuKUKH7231xTIvbC3bMfQcKwo43eIrvMtes5S8a4WP+v4eqR/yp/rA0Tjk9N1RNHfi/aSAA0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790785461; c=relaxed/simple; bh=yiJjWkVCux1EdZLm0s9JQXuoOW1fvd/6wufu/O5ZPcE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G/glOTbiXb5CIe8UbGmiaSxwQSwaJhjpPVPGWL4DUqWu5XJf1LrE9NGZzJGZmbMEvBwCA8TAeBoLNJ0iQrwFjEkQ8Ek+wqb5ibAK26UI9mknuVkJC8TlpvfqN4l8Fi3OCHYZYMd6do2b0fH6/8wazf4RS2lMcNT5PKbn5krg1Y0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wltwOtA3; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wltwOtA3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05C1E1F000FF; Wed, 30 Sep 2026 16:24:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790785452; bh=F3w053Ujv9Wj+DUDlpT02nQemaYu5Rgy+3LWUB81voc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=wltwOtA3jU1ztH279WwYbKuF9nT5PEzbsGtA46/kO13Pj90v/NSHiitQ38XhlSSpx zNlYc1vxJLhSbTzRsJ6ajWgrLfwaCCHXWUL0RlG4EstA/SO5OZypwA3HD1cIWNHDLX Lqn0VWIMXzuFLUrEjj3SIydb298ZddXZVXRJn78k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhongqiu Han , Viresh Kumar , "Rafael J. Wysocki" Subject: [PATCH 6.1 514/982] cpufreq: zero-initialize policy cpumask before sysfs publication Date: Wed, 30 Sep 2026 17:20:50 +0200 Message-ID: <20260930152427.818736875@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152416.775402466@linuxfoundation.org> References: <20260930152416.775402466@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhongqiu Han commit 54d37bcf2f497140b9207968557ddb484058e749 upstream. cpufreq_policy_alloc() allocates policy->cpus with alloc_cpumask_var(), i.e. without __GFP_ZERO, unlike the sibling related_cpus and real_cpus masks. With CONFIG_CPUMASK_OFFSTACK=y the mask is a separate kmalloc_node() allocation, so its bitmap holds whatever the slab allocator left behind: cpufreq_online() cpufreq_policy_alloc() alloc_cpumask_var(&policy->cpus) /* bitmap is uninitialized */ kobject_init_and_add() /* policy%u/ appears in sysfs */ cpufreq_policy_online() cpumask_copy(policy->cpus, cpumask_of(cpu)) /* first valid value */ This leaves a window in which the sysfs attributes are already reachable while policy->cpus is still garbage. show()/store() gate on policy_is_inactive(), i.e. cpumask_empty(policy->cpus), so a non-zero bitmap makes them run the attribute callbacks on a policy that is not initialized yet. Fix this by using zalloc_cpumask_var() for policy->cpus. Fixes: 2fc3384dc75b ("cpufreq: Initialize policy->kobj while allocating policy") Cc: All applicable Signed-off-by: Zhongqiu Han Acked-by: Viresh Kumar Link: https://patch.msgid.link/20260901143635.4106960-1-zhongqiu.han@oss.qualcomm.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/cpufreq/cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1216,7 +1216,7 @@ static struct cpufreq_policy *cpufreq_po if (!policy) return NULL; - if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) + if (!zalloc_cpumask_var(&policy->cpus, GFP_KERNEL)) goto err_free_policy; if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))