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 807D32F12D0; Fri, 17 Oct 2025 15:19:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760714384; cv=none; b=LwLyFrlhqtd3/0f5krE3ddVlTc6ERPIilgmGnHk8lzubWfYFnHelnL/P2l1QdmJ+cMq8nzKGILVGaifhMsRGsOWT8ngfRgeXvJFeAuUvZ/ZkEkro0dZaslCDH/5TJklFcgDuUItzXkwnr74tVPvxoUJCAFBTZRqo9k5aa85y6Rs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760714384; c=relaxed/simple; bh=K74L/tsCExi+efd/7e42CmQu4g3mWwH/lk08+Qc36WE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tk9sRncPV1HNVGwwUpsKMVx3rIO3ZnJKx6G54ixZomg2F6pCf3s8MIvZCGvf0LAd6hzw8bi+AzYHFTqqTvK2R+sOuhveHokI8RfjXHYN1fhduWOp6iNcXeZRnb/wcZIJCVxcc//FPWd/8efQMNtO7aHwcIRU5hOEovZbIAKT73g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YSSf78Uc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="YSSf78Uc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 064E9C4CEE7; Fri, 17 Oct 2025 15:19:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760714384; bh=K74L/tsCExi+efd/7e42CmQu4g3mWwH/lk08+Qc36WE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YSSf78Uc4GT4MwbiJy2JL3RnpECVXn/OlEUNV91WoVuOBZAvhneN8SK8+UFaOaDy3 MbdgVpA9eAdciJE7xa+nDRIaRvSD8mTPXSAQ+NREEIQDnHQuFu8XEKmBxBJA+SyQZd hzKCYkkuIHKCF5oXV7wVLBL4B5XTWfWCebr8GV1M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Rafael J. Wysocki" , Zihuan Zhang Subject: [PATCH 6.12 126/277] cpufreq: intel_pstate: Fix object lifecycle issue in update_qos_request() Date: Fri, 17 Oct 2025 16:52:13 +0200 Message-ID: <20251017145151.727808267@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145147.138822285@linuxfoundation.org> References: <20251017145147.138822285@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rafael J. Wysocki commit 69e5d50fcf4093fb3f9f41c4f931f12c2ca8c467 upstream. The cpufreq_cpu_put() call in update_qos_request() takes place too early because the latter subsequently calls freq_qos_update_request() that indirectly accesses the policy object in question through the QoS request object passed to it. Fortunately, update_qos_request() is called under intel_pstate_driver_lock, so this issue does not matter for changing the intel_pstate operation mode, but it theoretically can cause a crash to occur on CPU device hot removal (which currently can only happen in virt, but it is formally supported nevertheless). Address this issue by modifying update_qos_request() to drop the reference to the policy later. Fixes: da5c504c7aae ("cpufreq: intel_pstate: Implement QoS supported freq constraints") Cc: 5.4+ # 5.4+ Signed-off-by: Rafael J. Wysocki Reviewed-by: Zihuan Zhang Link: https://patch.msgid.link/2255671.irdbgypaU6@rafael.j.wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/cpufreq/intel_pstate.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1582,10 +1582,10 @@ static void update_qos_request(enum freq continue; req = policy->driver_data; - cpufreq_cpu_put(policy); - - if (!req) + if (!req) { + cpufreq_cpu_put(policy); continue; + } if (hwp_active) intel_pstate_get_hwp_cap(cpu); @@ -1601,6 +1601,8 @@ static void update_qos_request(enum freq if (freq_qos_update_request(req, freq) < 0) pr_warn("Failed to update freq constraint: CPU%d\n", i); + + cpufreq_cpu_put(policy); } }