From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 0B88729408; Fri, 7 Mar 2025 03:16:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741317403; cv=none; b=j5VOOMW5StWbFxfq+27EXKlhZVIJ07IJn9P4G9pdD/C8QSNq0qmxI+sUIF9ItK8gdF164TFyF0fxkyYAPwrti+HYM83QPzBZS3edU4aLfD3IEb6vbCOLhI5Xq2mF5KnpT7q9cEkwE7Z0WJEU1GwXNLfKkIfNZQQKerb5cihLkv0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741317403; c=relaxed/simple; bh=zUvXikN8bxMHia3xeJ7XhbVG/7tEYVBGwGZ5hGrnaBo=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=IRAloSfIuVp8mo0nJQ5vJwN368sEfVEBQOhMtswyqd1OEniYuWJRwzIozuBV9XbQl7eHnSCT4hzTPRQ/LG70J6dwJse3byTeNNlSL0/vLWBH0KswEI6mXgfJ04OQQNxB9mokG6mhoIgJy9gbSBsx1qdErSOMGLVcT+l7kEpB5qI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.194]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Z8BFF4VjWz9wPj; Fri, 7 Mar 2025 11:13:21 +0800 (CST) Received: from kwepemd100020.china.huawei.com (unknown [7.221.188.213]) by mail.maildlp.com (Postfix) with ESMTPS id 54C111400CF; Fri, 7 Mar 2025 11:16:30 +0800 (CST) Received: from [10.67.110.73] (10.67.110.73) by kwepemd100020.china.huawei.com (7.221.188.213) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 7 Mar 2025 11:16:29 +0800 Message-ID: <0bea64d3-34bd-4c4f-8386-ce29acaf5f6c@huawei.com> Date: Fri, 7 Mar 2025 11:16:29 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: CVE-2022-49623: powerpc/xive/spapr: correct bitmap allocation size To: Greg KH , , CC: , , , "youbowen (A)" References: <0af1c796-aa08-4284-ae6b-470fa75799b5@huawei.com> <2025030618-opal-chomp-5731@gregkh> From: "zhangjianhua (E)" In-Reply-To: <2025030618-opal-chomp-5731@gregkh> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemd100020.china.huawei.com (7.221.188.213) Yes, there is still some confusion about this bugfix patch. Hope Nathan and Michael can explain and give more details. 在 2025/3/6 21:58, Greg KH 写道: > On Thu, Mar 06, 2025 at 09:41:41PM +0800, zhangjianhua (E) wrote: >> Hi Greg， >> >> The commit message of this patch show that it occurs out-of-bounds of >> xibm->bitmap，the reason is that the allocated object can be smaller than >> sizeof(long) while bits is small. >> >> However, it is incorrect.  The kzalloc interface allocates memory in the >> unit of byte while bitmap_zalloc does based on the number of bits after >> rounded up, the space allocated by the kzalloc is not less than that >> allocated by the bitmap_zalloc. Therefore, replacing the kzalloc with the >> bitmap_zalloc does not solve the problem. In fact, the problem of >> out-of-bounds access does not exist. For instance the xibm->count is >> 3，kzalloc and bitmap_zalloc both return 8 bytes，it's enough for all >> bitmap. Although using the kzalloc wastes some memory, it does not create >> any real problems. >> >> Maybe this CVE should be rejected? > We will be glad to reject this if you think this does not actually fix > anything at all. If so, just let us know. > > thanks, > > greg k-h > >