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 DE8C431B83D; Mon, 27 Oct 2025 18:54:43 +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=1761591284; cv=none; b=BU07G9pqlZSumYBoe28HPBUf3vEukLnLytoithr3gwxwAkfazHo0n6z6vYDMyuZiZkWZsLEGryfCeUZDOfWp95ZZG06jcadCmZp0KFcYkyUdbZ4HDgg5k9KATsLmeX1CiyKa+yNuf1VdvfrJ0EO9pAZ1Hjgof5dDbnHeUebd2vs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761591284; c=relaxed/simple; bh=N1LMQB45h4pO+pfGnV/jOGpDDzwwRkrzVmp4i16dseY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D+myvebPFzjbwXg6dHczUngSIUUUBXb3ewrurM/PKk2K9mYpWgCuniM91DJq9rxpVUjVGcwxd9hDg9Dkk7U43L53P3KIAVdCFaW9mIA+jyStWoXg9kh0AKJQJqN/K9F/Ucp7yLgrTRxEUuyDipKmYG37kaa4M/ZZ0cs8BvjG2hM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wYA5rQ0L; 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="wYA5rQ0L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71490C4CEF1; Mon, 27 Oct 2025 18:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761591283; bh=N1LMQB45h4pO+pfGnV/jOGpDDzwwRkrzVmp4i16dseY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wYA5rQ0LLWMlQaStgoHMCzIcqmbgxTxRSYoKMp/CVI/SILyjGweqxztsdkOFBnlyx +fkR+8TPY9OGZJeapaOAtKh2C/0n+iHM6cM8ywiusKwLB30CrhjstNxBcQ7aksEW6c CSSjzNd96zCtTgzFs4B9nhgDvCKXPtssPDsD4nJQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Rafael J. Wysocki" , Zihuan Zhang Subject: [PATCH 5.10 137/332] cpufreq: intel_pstate: Fix object lifecycle issue in update_qos_request() Date: Mon, 27 Oct 2025 19:33:10 +0100 Message-ID: <20251027183528.251906562@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183524.611456697@linuxfoundation.org> References: <20251027183524.611456697@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 5.10-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 @@ -1205,10 +1205,10 @@ 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_max(cpu, &turbo_max, &max_state); @@ -1227,6 +1227,8 @@ 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); } }