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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6C587C433F5 for ; Wed, 19 Jan 2022 00:52:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=TN0oDzRuzDCJbJVrRiLF1h9ethKZdI8RvT1i1VSfcYM=; b=HUWQYWE3L5l2KD YiXiOXSTTFA5dt2ZGB898sgrkl09WxMCU8R8406e8meCZc5X5km2HdFxW6DYygNTKVZdmMWTNCwW3 rymxbbzc1CWqHLRKlNcDVCGtbI9NZs6wOLCa77xFL+j6GX3G9NdZ79PSGxpidKhJqz4+pvi6Bv6Pq H2kdMu6C9TGj15JUGM7sdRuLbdwn74AY9OGtM8CtMQYsE9H6BtIXZM2VzPZ6EVuHMN7G6FeMF8/gM f8mMqygEt9p9uc5sTVXqnNHpByQZ/YwQ1cYq3okuxg2/ViVYWYf3IL6NXkW01Ftz0sm1xRjHxFTk+ BbI1lbsjkeZi2UDnYbjQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9zCJ-003NiP-JJ; Wed, 19 Jan 2022 00:51:35 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9zCH-003Ni1-Hd for linux-arm-kernel@bombadil.infradead.org; Wed, 19 Jan 2022 00:51:33 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bSFNXBAL3L/sZMcUTYCHF8j9CNgzUTePNEfP42fi6WM=; b=ITKBmPkjINkr+kVaj6Y+dKIcDI BvqOngu/9IT5Rn4s9sTLn2PzesWshv2YBsi96+rofQ3+BVYoqVcjkMtC6rlUmPtTMSq/ul5NyOAI/ q9DfCSH+rEK9qqPiFSGY2rKngDe1XMI3RfAvmOn5EOBwbK7ns9ErE/q+y6JdyZZMHbSjln06B+F5d HQZHhSFi8mSfC9SP34IMzIrPdTN5zgIjUDjXMh1S7jqBjTqVUJ0QXKMfoUJYqorDpNzxB298VO7vG XIkw1MnizDFVQjXTcqksKReY9AwdDKZBSf1YV0Kkn1jYYD8jqYGonSDHHpgNXaVS+PGt16D+BzX3X cqw5cPlw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9zCB-009rPJ-HZ; Wed, 19 Jan 2022 00:51:27 +0000 Date: Wed, 19 Jan 2022 00:51:27 +0000 From: Matthew Wilcox To: Yury Norov Cc: Catalin Marinas , Will Deacon , Andrew Morton , Nicholas Piggin , Ding Tianhong , Anshuman Khandual , Alexey Klimov , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Uladzislau Rezki Subject: Re: [PATCH] vmap(): don't allow invalid pages Message-ID: References: <20220118235244.540103-1-yury.norov@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220118235244.540103-1-yury.norov@gmail.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jan 18, 2022 at 03:52:44PM -0800, Yury Norov wrote: > vmap() takes struct page *pages as one of arguments, and user may provide > an invalid pointer which would lead to DABT at address translation later. Could we spell out 'DABT'? Presumably that's an ARM-specific thing. Just like we don't say #PF for Intel page faults, I think this is probably a 'data abort'? > Currently, kernel checks the pages against NULL. In my case, however, the > address was not NULL, and was big enough so that the hardware generated > Address Size Abort on arm64. > > Interestingly, this abort happens even if copy_from_kernel_nofault() is > used, which is quite inconvenient for debugging purposes. > > This patch adds a pfn_valid() check into vmap() path, so that invalid > mapping will not be created. > > RFC: https://lkml.org/lkml/2022/1/18/815 > v1: use pfn_valid() instead of adding an arch-specific > arch_vmap_page_valid(). Thanks to Matthew Wilcox for the hint. > > Signed-off-by: Yury Norov Suggested-by: Matthew Wilcox (Oracle) > --- > mm/vmalloc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index d2a00ad4e1dd..a4134ee56b10 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -477,6 +477,8 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, > return -EBUSY; > if (WARN_ON(!page)) > return -ENOMEM; > + if (WARN_ON(!pfn_valid(page_to_pfn(page)))) > + return -EINVAL; > set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); > (*nr)++; > } while (pte++, addr += PAGE_SIZE, addr != end); > -- > 2.30.2 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel