From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuMmJK/lU0U20tnvCkbsOuJTNQqcqfGGpGnSsSDAIN5PwfgvnjRwHFKdYwTHKLExS7WDA/r ARC-Seal: i=1; a=rsa-sha256; t=1520356137; cv=none; d=google.com; s=arc-20160816; b=lj4WaHpOwmvr3K9c7Ou0mOG/vAfDWf6IZmHRzEtIBKb9T3U9lwKc1kd9YW7wyAI/DT 4lTgVCs/K3jXnTNIeq3SspJVR7RMqq5qr2W37BwwJlVGuY3vhxQiYn+1klFZCr9LBomz rlr0Vy3brxIducCqHYVCj8KG5Do5i2WfK6KR7e7Iy2TySUUTzOVoqcF1ClxjiEx/uNyb A8omoDDXtJFm/Il6j7S2ht631IfzD0IW0wF7hjrpfDVjlsCgpEjAsuwwfEY9zbQjcZi3 zUMIoqCfXDVJw2ncrPjNsei/bF5Igeuk+jmzZztHp39qwxZ/a/+WrlAAkFoXxFeaKV7p 6Y7w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-language:content-transfer-encoding:in-reply-to:mime-version :user-agent:date:message-id:references:cc:to:from:subject :dkim-signature:delivered-to:list-id:list-subscribe:list-unsubscribe :list-help:list-post:precedence:mailing-list :arc-authentication-results; bh=aAcLK1x/oceKFh+9o6qTLj0vQN72rvwl2Gj3RuMPqOM=; b=E4gdN0agh4XlUrX1l3S4Nl6LxSoh+u0grc5sGss53iVdLI41PBIojTGAHIWPlqDRDr rzJIkyVxKX8P5cSyCl0kLUOlUddjAgh/Npa/64P9EakSKtGp8BIrJmTl6cpoCfTf2JOJ n+X3RMMxIpc1P9oKUDytP9bG72iKEfxq1TnS8Tut1qKEzMqZDV0kerFaYIwzV5pBbzrU /NC5oIhisXjojw/UEkJG8Uo7OHeXzQfyOwMPNJExfDIGcH3ECbffucJahLCIlcJgB1wA 5AAbGrBfkCSM6z5g8szCFfdNAEW8oi4uZ0BTD7fQNCAI6fn8BhcFTnCWbtmkmYnP1780 fNYg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=TwGmFmcF; spf=pass (google.com: domain of kernel-hardening-return-12152-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12152-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=TwGmFmcF; spf=pass (google.com: domain of kernel-hardening-return-12152-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12152-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: Subject: Re: [PATCH 6/7] lkdtm: crash on overwriting protected pmalloc var From: J Freyensee To: Igor Stoppa , david@fromorbit.com, willy@infradead.org, keescook@chromium.org, mhocko@kernel.org Cc: labbott@redhat.com, linux-security-module@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com References: <20180223144807.1180-1-igor.stoppa@huawei.com> <20180223144807.1180-7-igor.stoppa@huawei.com> <1120e8fd-2f48-5b1f-7072-9bd8e2b82fbf@gmail.com> Message-ID: <679444bd-7b41-4fb0-d7ba-98ed86da86c5@gmail.com> Date: Tue, 6 Mar 2018 09:08:30 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1120e8fd-2f48-5b1f-7072-9bd8e2b82fbf@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593203814128727346?= X-GMAIL-MSGID: =?utf-8?q?1594208957004508212?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 3/6/18 9:05 AM, J Freyensee wrote: > >>   +#ifdef CONFIG_PROTECTABLE_MEMORY >> +void lkdtm_WRITE_RO_PMALLOC(void) >> +{ >> +    struct gen_pool *pool; >> +    int *i; >> + >> +    pool = pmalloc_create_pool("pool", 0); >> +    if (unlikely(!pool)) { >> +        pr_info("Failed preparing pool for pmalloc test."); >> +        return; >> +    } >> + >> +    i = (int *)pmalloc(pool, sizeof(int), GFP_KERNEL); >> +    if (unlikely(!i)) { >> +        pr_info("Failed allocating memory for pmalloc test."); >> +        pmalloc_destroy_pool(pool); >> +        return; >> +    } >> + >> +    *i = INT_MAX; >> +    pmalloc_protect_pool(pool); >> + >> +    pr_info("attempting bad pmalloc write at %p\n", i); >> +    *i = 0; > Opps, disregard this, this is the last series of this patch series, not the most recent one :-(. > Seems harmless, but I don't get why *i local variable needs to be set > to 0 at the end of this function. > > > Otherwise, > > Reviewed-by: Jay Freyensee >