From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) (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 59F942F5E; Thu, 20 Feb 2025 02:31:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740018699; cv=none; b=qAzZPwnQAikWc8f8cExFc7Y2Ia/+evt/nz+zerBO3NYUi0hnF7h+35vpBfOVO6X6mJRMwugob7Z6UkMKvuY6euXe1gstguZ57z27c5eEgSxIcMEZmTPh3YwvKGUd9ufoAU+XPHc1tdzuQtLrI6LSLAg1fyVG3YrwC/CTyd24PDc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740018699; c=relaxed/simple; bh=hTsNSbikiqFbBAoA46AmZ15cdx/rCAA4hup/c0bL4XU=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=ISAiu5ECp0YDQfOm0evy7niaxCqXPubC/I01ruVwDGwqmQ4X1lM7rA0ueCy0p1zX6WIKzrDyXVSYPbgOgdU1sI7xApA/r/2eMl1FA0xGyQy6l+j3FN4ffyI5x9YocnVOuj2R9kVYw0T/sIu4UczlF8Ti//m3iIRTd6ReS6ZmEEQ= 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=45.249.212.32 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 [172.19.88.214]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4Yyy2X1Gc4zpk6Z; Thu, 20 Feb 2025 10:32:04 +0800 (CST) Received: from kwepemk500005.china.huawei.com (unknown [7.202.194.90]) by mail.maildlp.com (Postfix) with ESMTPS id 32F151A016C; Thu, 20 Feb 2025 10:31:33 +0800 (CST) Received: from [10.174.179.234] (10.174.179.234) by kwepemk500005.china.huawei.com (7.202.194.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 20 Feb 2025 10:31:31 +0800 Message-ID: <2fe4c4d1-c480-c250-1ba2-1a82caf5d7fa@huawei.com> Date: Thu, 20 Feb 2025 10:31:30 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: Add Morton,Peter and David for discussion//Re: [PATCH -next] uprobes: fix two zero old_folio bugs in __replace_page() To: David Hildenbrand , Oleg Nesterov CC: Masami Hiramatsu , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Andrew Morton , Peter Xu , , , , , , linux-mm References: <20250217123826.88503-1-tongtiangen@huawei.com> <3b893634-5453-42d0-b8dc-e9d07988e9e9@redhat.com> <24a61833-f389-b074-0d9c-d5ad9efc2046@huawei.com> <20250219152237.GB5948@redhat.com> <34e18c47-e536-48e4-80ca-7c7bbc75ecce@redhat.com> From: Tong Tiangen In-Reply-To: <34e18c47-e536-48e4-80ca-7c7bbc75ecce@redhat.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemk500005.china.huawei.com (7.202.194.90) 在 2025/2/20 0:12, David Hildenbrand 写道: > On 19.02.25 16:22, Oleg Nesterov wrote: >> On 02/18, Tong Tiangen wrote: >>> >>> OK, Before your rewrite last merged, How about i change the solution to >>> just reject them immediately after get_user_page_vma_remote()？ >> >> I agree, uprobe_write_opcode() should simply fail if >> is_zero_page(old_page). > > Yes. That's currently only syzkaller that triggers it, not some sane use > case. OK, change as follows: --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -506,6 +506,12 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, if (ret <= 0) goto put_old; + if (WARN(is_zero_page(old_page), + "uprobe should never work on zero page\n")) { + ret = -EINVAL; + goto put_old; + } + if (WARN(!is_register && PageCompound(old_page), "uprobe unregister should never work on compound page\n")) { ret = -EINVAL; If ok, i will send v2 soon. Thanks, Tong. >