From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (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 EBE001EE7C6 for ; Fri, 17 Apr 2026 03:29:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776396553; cv=none; b=lUNdlK4tozSfTuXSR/RvoSmjosQdh3DdI/U9rP2D9SBm+TDBuIYswavBOWA3vUIlaKedUg6REBDjNYQkZ4PHsw49m6XugAgl1+nhv7OfdcQnh+dNmAFdY6qwCwtkdkdVxnqV2ciP33PDWcvRjI9Rx60P0QMsMTb+FZIfSRp+HjQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776396553; c=relaxed/simple; bh=eTyuvWAT+AhQjCTZ+fAnI3d3JtxZ9B0bTLJ9qcIebw4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=C4eCA70+6sC4AvtQ8Z6GwkGqF+pbKaa5zk+Ovv7icrYPHYPZXSWP5NHFFZjghWXvbg3qvxPccwQIqCHKhzbyBRu5x5tgp6+DZdbgabLCPIXkh7oDI4OfWnw5+n830aiq2OyRgEhRI7Am2K4MzG0nn30NtKc2vF53bGg4OuWDycQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=CnZAiVgI; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=iSmNPZZE; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="CnZAiVgI"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="iSmNPZZE" Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 63H0fgJG1092212 for ; Fri, 17 Apr 2026 03:29:11 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= Hw4o6jWf80ge7uRE5y0KQI+QVn0A4UOeJXjsDnVDqa0=; b=CnZAiVgIPp17JV0a k6hRhxXiQWsHIpbHOa3uPsP405FOb0o3u2/A9rC46IHXtiZbqTa+k9gDd7mOEBGm 8PiMTwZTeDZDozP13sV2oFvKC8T8mjt8f9a1IVpfctcuwJelo6i+M1LhWZ0i0psa x8c7ts24HvcsTPdm00sBHOPvwJXsqHb6K3DOLio4yR1lLMOKTlRUS6M5Zpr9CbT4 otGrsO5sBTWYFshBnPcu2qmHEAqfeV9gULa7pu3rLPqx4bY2hfE96fSwyVORnETL NXAfpMiFwW/uUe3XFzEzbzl8BYqDCJrMmbVkFH9dO5C8sLj/3yfzE6MRvpt/VYC5 +wE7tg== Received: from mail-pg1-f199.google.com (mail-pg1-f199.google.com [209.85.215.199]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4dk227t92c-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Fri, 17 Apr 2026 03:29:10 +0000 (GMT) Received: by mail-pg1-f199.google.com with SMTP id 41be03b00d2f7-c769e2b1bd0so77878a12.2 for ; Thu, 16 Apr 2026 20:29:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1776396550; x=1777001350; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=Hw4o6jWf80ge7uRE5y0KQI+QVn0A4UOeJXjsDnVDqa0=; b=iSmNPZZEPYJNsEyN/BE5sCbX6TTs9CtoMCiufkYb9hRgLntz5SfNN3q1J8JFuXK+/A PJIw2JAWXLd/daF8Z/Jf/78y27/7lnOdLsN087inuH1khl9N7j4yl1JBD+v7q+LJ9BlT tRH8lyGQcMu83JAaRJnWFfb5xfDNARjGfYyydEfcOWXpQcGM1SGfWvEQeMopevpxq74t csJoocdTF122UeT2rPBEPOQr1fNcy9Ka12hlsK7WUYoqpXTpy+TAfPslLrG8eeI4DFx0 cyy6n8IhoHlI80hizx7+1dZhhouCpItAbyQuYOzmb6pD6ifOKq7LsAAhTBYbRiCQuGlO tR3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776396550; x=1777001350; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Hw4o6jWf80ge7uRE5y0KQI+QVn0A4UOeJXjsDnVDqa0=; b=jmXcgifP2307V8WMg5KhV+ENBFgxf0kK930Sw9vRSwuXaxbAYecD2fzqnqqORoo+19 rdo/IywdSoVKJ9YfKK9f7ku+ok6ldB5jmAJPa0TQfVG7UGiCnFkRUC1vicWuGPegs3D8 3UzpC4prp0FXD3bGjwNXV4tykMb38CnQ97GGkBkn0n1YxQagJRw6co5q2EDoG6YexxXL pDmxLYXWltC3EvkkMjSvOrQ4iX49C4S9RJ3Q4p236gAvuhHwX9ZHnVFtUMVlCOCPNdi3 hIHjY1UpRw1rlhH5ShvFIsAGGdm/olXLaBfFPrQcLGzw9rw4Lt5iMDayoopfvuuAmkGs tPZg== X-Gm-Message-State: AOJu0YyKMTQWl4SCezPxfIhAY0RDsP/+wyVA/sR1w/Ym+5cgWntMHJxm kqqe/1QYfawkdZHa6RJeWw0DagUJxFIUcEVCmY6hRGmmTRAqYND9sQnR4k8lj5QQD7KzC18aXS7 md1g7cGBTwQ/1cvTJGeM19/J7cJbSv2L0UUCM3CjgFX1KqB0USSd/PURU0qQQeA== X-Gm-Gg: AeBDievH44kU5LiylHPLWserzaLOiL1ZDJyerprFiHQ3giqLte8RApOWXkosODQ9Ee7 qf3EtQ2vWwpK1PL3nBT4NPX7GrYby//GApb/pUF4a95c4peFC4zNQdLD10r82lgrlxzpcMB36FD /zen9QABvOwELXnRNL0l/L7b+HW2Asd9jm1NmEZBimI/pwIkf0UIQIilphRBp4KLNvOlHnsliUh 1a2K9zvupJbhVVl0W+Juk7SGAge9UAcY/8xvQJkAA2XVxQipWOa1Pvn3uTZt9Qbyqq3T2Ryzv+3 2cmXshHWYjRmbZvC7ifrDhxyu80dPGsHlz5vpJ6Nadz/PX/EZM2a4AVIXUTll/zvJx/tBR7meqn HYhch4Kqi82sEA2tdyrxi1A/Wgcc8TlV1dXv9wKRlF4JRlliPpIi7YGKOOH7xa3ehKJff0WSWiD EGNdY3x0doaZtLMeI6yg== X-Received: by 2002:a05:6a00:2da2:b0:82a:7471:eb90 with SMTP id d2e1a72fcca58-82f8c8bbe01mr903986b3a.30.1776396549873; Thu, 16 Apr 2026 20:29:09 -0700 (PDT) X-Received: by 2002:a05:6a00:2da2:b0:82a:7471:eb90 with SMTP id d2e1a72fcca58-82f8c8bbe01mr903957b3a.30.1776396549407; Thu, 16 Apr 2026 20:29:09 -0700 (PDT) Received: from ?IPV6:240e:404:2520:fc28:96c:a6d:1e5e:8796? ([240e:404:2520:fc28:96c:a6d:1e5e:8796]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82f8e981a0asm258949b3a.3.2026.04.16.20.29.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 16 Apr 2026 20:29:08 -0700 (PDT) Message-ID: <203f2e52-bf9d-4055-88bd-d911bfecf082@oss.qualcomm.com> Date: Fri, 17 Apr 2026 11:29:04 +0800 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] cpufreq: pcc: fix use-after-free and double free in _OSC evaluation To: Yuho Choi , "Rafael J . Wysocki" , Viresh Kumar Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, zhongqiu.han@oss.qualcomm.com References: <20260416144621.93964-1-dbgh9129@gmail.com> Content-Language: en-US From: Zhongqiu Han In-Reply-To: <20260416144621.93964-1-dbgh9129@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDE3MDAzMSBTYWx0ZWRfX01xqyOX1zTch AQ8GhbysO9Qtj8gVf6lsWHEmT2NiA/F6h/MVZm8fYD1kQV6HM80E7LqHkw73QBvAmuOWlL8E5Nl ALaqnhlSDBx/VAzAPIX90z54vmqNC5w0zSW7wAcbK+naL3TzHe9zNUxg8jDGAgq8iVJ16mog7EX kqkyFvUu/cSIAyx6V2T/0lFdyWBgvh6q/x0bKF5HI223wOj35p77AxPMibyMusTy0gZf+jGohYK bw/oaCW1H5RusOWxhx6s2ETvhcOTcNFWD3kA5thlVZa+cHZ1Er8ELrtfJ43+s9tBE3NPXyrKgY2 hrlM1uoXaES8NlOkmMG4HeTg5ONc5Q77SdkaSWkTN/uPM3i04Tg5QxDy9PQp0E1RO1hbtw+/5gD QKyrdBsvVSntCLzRK0wTDbPwSJX2Ey1jnzOyvRhgBllG92/9TzGHw1Jgcw46/Qs+GqmkSw+onh4 DMyJTLA9v2BDfc8WQ6Q== X-Proofpoint-ORIG-GUID: tBQSeJwgw3xIWvYXc5vvFYRfREJLW6OV X-Proofpoint-GUID: tBQSeJwgw3xIWvYXc5vvFYRfREJLW6OV X-Authority-Analysis: v=2.4 cv=Iuoutr/g c=1 sm=1 tr=0 ts=69e1a906 cx=c_pps a=Oh5Dbbf/trHjhBongsHeRQ==:117 a=xqWC_Br6kY4A:10 a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=yx91gb_oNiZeI1HMLzn7:22 a=pGLkceISAAAA:8 a=EUspDBNiAAAA:8 a=aIcA-GvUrLZ_5u2auIMA:9 a=QEXdDO2ut3YA:10 a=_Vgx9l1VpLgwpw_dHYaR:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-04-16_04,2026-04-16_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 adultscore=0 suspectscore=0 clxscore=1015 impostorscore=0 malwarescore=0 priorityscore=1501 spamscore=0 lowpriorityscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604070000 definitions=main-2604170031 On 4/16/2026 10:46 PM, Yuho Choi wrote: > pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the > two-phase _OSC negotiation. Between the two calls it freed > output.pointer but left output.length unchanged. Since > acpi_evaluate_object() treats a non-zero length with a non-NULL > pointer as an existing buffer to write into, the second call wrote > into freed memory (use-after-free). The subsequent kfree(output.pointer) > at out_free then freed the same pointer a second time (double free). > > Reset output.pointer to NULL and output.length to ACPI_ALLOCATE_BUFFER > after freeing the first result, so ACPICA allocates a fresh buffer for > each phase independently. > > Fixes: 0f1d683fb35d ("[CPUFREQ] Processor Clocking Control interface driver") > Signed-off-by: Yuho Choi Reviewed-by: Zhongqiu Han > --- > > Changes in v1: > - Drop spurious #include "acpi/actypes.h" (Zhongqiu Han) > - Keep kfree() between the two calls and reset output.pointer = NULL > and output.length = ACPI_ALLOCATE_BUFFER > > drivers/cpufreq/pcc-cpufreq.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c > index ac2e90a65f0c4..a355ec4f3dd4c 100644 > --- a/drivers/cpufreq/pcc-cpufreq.c > +++ b/drivers/cpufreq/pcc-cpufreq.c > @@ -352,6 +352,8 @@ static int __init pcc_cpufreq_do_osc(acpi_handle *handle) > } > > kfree(output.pointer); > + output.pointer = NULL; > + output.length = ACPI_ALLOCATE_BUFFER; > capabilities[0] = 0x0; > capabilities[1] = 0x1; > -- Thx and BRs, Zhongqiu Han