From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD598C2BA15 for ; Sat, 4 Apr 2020 19:00:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 79DDA206F5 for ; Sat, 4 Apr 2020 19:00:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Se6bVwp2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79DDA206F5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 121BC8E000A; Sat, 4 Apr 2020 15:00:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0D28C8E0009; Sat, 4 Apr 2020 15:00:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F03238E000A; Sat, 4 Apr 2020 15:00:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0108.hostedemail.com [216.40.44.108]) by kanga.kvack.org (Postfix) with ESMTP id D2F0B8E0009 for ; Sat, 4 Apr 2020 15:00:16 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 82F33180AD81A for ; Sat, 4 Apr 2020 19:00:16 +0000 (UTC) X-FDA: 76671088032.05.fall24_76c65c6f4ef5e X-HE-Tag: fall24_76c65c6f4ef5e X-Filterd-Recvd-Size: 5530 Received: from mail-lj1-f194.google.com (mail-lj1-f194.google.com [209.85.208.194]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Sat, 4 Apr 2020 19:00:16 +0000 (UTC) Received: by mail-lj1-f194.google.com with SMTP id r24so10396816ljd.4 for ; Sat, 04 Apr 2020 12:00:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=YeDkwAMRYs+8ztmifHIoEPIXNMJQCvkCAGpkS5dmvN8=; b=Se6bVwp29Lk9h32ohyXnkTxpZWN2oAfGGVMd9atHYZHwssaXsgVFNMSGf5DdlCbS5n 6oMYxUg+7Gpue3tjRTBS5k89CcsgtLlf71rBX1TwAMW2RoZyQ6FqPCmuVCnXoewymFwr u8+V2GzQKBi9LBHXE+i+WUEonct7JWKbF9uOLGAFPcxz/w5tqvXSsh5bJ2QSnNb/8xkJ CktrwX+nNwrI50JmXZzyqCqgE4gdaweoPfW9MysIEhaLZKxZJrfXXq8wukhQKtvBR8UY e4Z4+lFcL9gkfyE3SXe+R69AUCZGXnq9OAx8sH1b/+xvqhgGUG72/UY/Z2MQ1iYTTBl4 NoIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=YeDkwAMRYs+8ztmifHIoEPIXNMJQCvkCAGpkS5dmvN8=; b=ZXenfrr618A5HkT+Zr3n0pL8b24b1NVkC+vKWfc9TX3nSkKFGpOdajbdrN+sYIDlt1 tqa6p2IxIIwONsK+qBR4jE583/cVgaE1MiV7YkYDqHTQmWjvI8R0+RGhZkndwNrQ+yJU uGhHsPb3H4ew1KjkJVF0siWKrLwxD6MsYBwiq4+pPUqrZzArpNxXq4BNwhGMXCriUIjY Be43y9ygTIeDMTcnTwiDVzvaw+5d0td3M28l88q0C9ri4DZkZC/AWQEudTVVAm1mjUTg ggU0dArF8dtSjsvl76Tz51Mi3rxDLOMk3TqVqYZ5zFllkjj968+kFoSsZSJFLrEKKf8t Qd6g== X-Gm-Message-State: AGi0PubFawzc+CtM8dmIS3zhdXkLQiOZvSUbNQyi7AvtP4t5AF/QYtwi prnqlUID8RnuK6VxWToOCi0= X-Google-Smtp-Source: APiQypKQao45kx5IAtNq8FzqB2IyR/T1wX8CRcNWAOFeyv7EXc1A4vq3Xc8Q6zeR4/1eKhFwlFJs+A== X-Received: by 2002:a2e:98d7:: with SMTP id s23mr7671487ljj.154.1586026814726; Sat, 04 Apr 2020 12:00:14 -0700 (PDT) Received: from pc636 (h5ef52e31.seluork.dyn.perspektivbredband.net. [94.245.46.49]) by smtp.gmail.com with ESMTPSA id d6sm10327196lfn.72.2020.04.04.12.00.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 04 Apr 2020 12:00:13 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Sat, 4 Apr 2020 21:00:07 +0200 To: Peter Zijlstra Cc: Uladzislau Rezki , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jroedel@suse.de, vbabka@suse.cz, Thomas Gleixner Subject: Re: [PATCH] mm/vmalloc: Sanitize __get_vm_area() arguments Message-ID: <20200404190007.GB424@pc636> References: <20200403163253.GU20730@hirez.programming.kicks-ass.net> <20200403181818.GA5538@pc636> <20200403185300.GD20730@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200403185300.GD20730@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Apr 03, 2020 at 08:53:00PM +0200, Peter Zijlstra wrote: > On Fri, Apr 03, 2020 at 08:18:18PM +0200, Uladzislau Rezki wrote: > > On Fri, Apr 03, 2020 at 06:32:53PM +0200, Peter Zijlstra wrote: > > > > > > __get_vm_area() is an exported symbol, make sure the callers stay in > > > the expected memory range. When calling this function with memory > > > ranges outside of the VMALLOC range *bad* things can happen. > > > > > > (I noticed this when I managed to corrupt the kernel text by accident) > > > > > > Signed-off-by: Peter Zijlstra (Intel) > > > --- > > > mm/vmalloc.c | 7 +++++++ > > > 1 file changed, 7 insertions(+) > > > > > > --- a/mm/vmalloc.c > > > +++ b/mm/vmalloc.c > > > @@ -2130,6 +2130,13 @@ static struct vm_struct *__get_vm_area_n > > > struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags, > > > unsigned long start, unsigned long end) > > > { > > > + /* > > > + * Ensure callers stay in the vmalloc range. > > > + */ > > > + if (WARN_ON(start < VMALLOC_START || start > VMALLOC_END || > > > + end < VMALLOC_START || end > VMALLOC_END)) > > > + return NULL; > > > + > > > return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE, > > > GFP_KERNEL, __builtin_return_address(0)); > > > } > > Peter, could you please clarify what kind of issues you had and how you > > tested? > > Well, I had a bug and corrupted text; but then I tested: > > __get_vm_area(PAGE_SIZE, VM_ALLOC, __START_KERNEL_map, > __START_KERNEL_map + KERNEL_IMAGE_SIZE); > > and that *works*. > Do you mean that you corrupted "text" by calling __get_vm_area(...) with special parameters? If so could you please show how you used it. > > __get_vm_area() is not limited by allocating only with vmalloc space, > > it can use whole virtual address space/range, i.e. 1 - ULONG_MAX. > > Yeah, I know, I'm saying it perhaps should be, because not limiting it > while exposing it to modules seems risky at best, downright dangerous if > you consider map_vm_area() is also exported. > Doing it to secure modules, probably is OK, but modules can also be reside within vmalloc address space. Thank you in advance! -- Vlad Rezki