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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 8F1D5C10F00 for ; Wed, 27 Mar 2019 18:04:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 604E9217D9 for ; Wed, 27 Mar 2019 18:04:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553709884; bh=ua7LJnVXX/Vm3FqF5WFEnE7RJx6RGO6dq81BORIG8QA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YW4qJB2NLnXmy70C3Z0ERJlHkF56RqCBpfxNE4Vdl5DOjBHUKKC9/GFjYqFQhDJi5 59rkJnnv0xUhjakXzTOKEl0uGVB8+slkMSyxEdMVSPkLKEyeICXMAFUHXWyJurUUYi ETopQKGLjgzn5l07wQPBhY0sEYSCVThEYVJetnyM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387429AbfC0SEn (ORCPT ); Wed, 27 Mar 2019 14:04:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:45424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731614AbfC0SEm (ORCPT ); Wed, 27 Mar 2019 14:04:42 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E7EB5217D9; Wed, 27 Mar 2019 18:04:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553709881; bh=ua7LJnVXX/Vm3FqF5WFEnE7RJx6RGO6dq81BORIG8QA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QBnpBF9rTVFd1ygqzoyhuGKxlIzPlX05PVO2NcF39NZBCktc4KBSbLO84jnJo3yCP AnV43znsOdRJIlPLhI2sN24gYi1OJMv/eKtHwkGWL+4GN9Y2Ic2eoyRuoIYa8CEweu aIEYb+3UYn8EEH9iw9vKoD9ShXT5XozcMehs7Ss4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Aneesh Kumar K.V" , Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.0 086/262] powerpc/hugetlb: Handle mmap_min_addr correctly in get_unmapped_area callback Date: Wed, 27 Mar 2019 13:59:01 -0400 Message-Id: <20190327180158.10245-86-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327180158.10245-1-sashal@kernel.org> References: <20190327180158.10245-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: "Aneesh Kumar K.V" [ Upstream commit 5330367fa300742a97e20e953b1f77f48392faae ] After we ALIGN up the address we need to make sure we didn't overflow and resulted in zero address. In that case, we need to make sure that the returned address is greater than mmap_min_addr. This fixes selftest va_128TBswitch --run-hugetlb reporting failures when run as non root user for mmap(-1, MAP_HUGETLB) The bug is that a non-root user requesting address -1 will be given address 0 which will then fail, whereas they should have been given something else that would have succeeded. We also avoid the first mmap(-1, MAP_HUGETLB) returning NULL address as mmap address with this change. So we think this is not a security issue, because it only affects whether we choose an address below mmap_min_addr, not whether we actually allow that address to be mapped. ie. there are existing capability checks to prevent a user mapping below mmap_min_addr and those will still be honoured even without this fix. Fixes: 484837601d4d ("powerpc/mm: Add radix support for hugetlb") Reviewed-by: Laurent Dufour Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/mm/hugetlbpage-radix.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/hugetlbpage-radix.c b/arch/powerpc/mm/hugetlbpage-radix.c index 2486bee0f93e..97c7a39ebc00 100644 --- a/arch/powerpc/mm/hugetlbpage-radix.c +++ b/arch/powerpc/mm/hugetlbpage-radix.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include #include +#include #include #include #include @@ -73,7 +74,7 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr, if (addr) { addr = ALIGN(addr, huge_page_size(h)); vma = find_vma(mm, addr); - if (high_limit - len >= addr && + if (high_limit - len >= addr && addr >= mmap_min_addr && (!vma || addr + len <= vm_start_gap(vma))) return addr; } @@ -83,7 +84,7 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr, */ info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; - info.low_limit = PAGE_SIZE; + info.low_limit = max(PAGE_SIZE, mmap_min_addr); info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW); info.align_mask = PAGE_MASK & ~huge_page_mask(h); info.align_offset = 0; -- 2.19.1