From patchwork Thu Nov 22 19:52:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 10694769 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CA1B41709 for ; Thu, 22 Nov 2018 19:54:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BB0A929710 for ; Thu, 22 Nov 2018 19:54:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AED5E2AF94; Thu, 22 Nov 2018 19:54:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0D07129710 for ; Thu, 22 Nov 2018 19:54:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 140FB6B2CEE; Thu, 22 Nov 2018 14:54:54 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 0F0536B2CEF; Thu, 22 Nov 2018 14:54:54 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F21506B2CF0; Thu, 22 Nov 2018 14:54:53 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id B2BB06B2CEE for ; Thu, 22 Nov 2018 14:54:53 -0500 (EST) Received: by mail-pf1-f198.google.com with SMTP id v79so3686960pfd.20 for ; Thu, 22 Nov 2018 11:54:53 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:from:to:cc:subject:date :message-id:in-reply-to:references; bh=2yY5eBgeLQ5vyKycEM63SfoZEzyeAKo8tsMENNgCu+A=; b=TsU4VGPw3QZBZINsl5mh/mbgApd2Jlw7uPBY7WZ3WTxbLSLqAM8EiBrUFKTsKitthT CfyJTl3Hh6c6Xd6YhZVeSnLIFyPKsI10u0tBsVtgdwXQOYXkdzcj4QnsCrHkqob8GCkD pQzfjIjrl+eWVM365+6f39YiHto+7npANR6vx5oDkcVtVDvbib99aJ/FN93Nx/vmBwtW qqWrMys31aWkhdL9x2nPokVxqyjtV55vu5CrwQnKcT3cvIZl1EpNZ+CG6rgC6ND6QxVo w4pcqEtzPTnV1K1cg1lY1vTWiSyGWoBld8PIBFTrcrqZRCkEmrHYH0xoXzP4B9/eTxqi 1LgA== X-Gm-Message-State: AA+aEWY7daZqG/r2fodf5cjcNtq4hcnbqdI9u0an6l+cI264MyvWM4wq 2ZY3Bp/uGv5vgocZ/V4Z1TEKA2XyMXxR2e26wsCO3FItNknsalt3uNXf42Vr2lu8jTVSSyKJO0J pQXINLGzSvnriXoI2jr0a9bXC1BpbUiXddv7tyYVkkIk7qcdbwNwR2QFZ3zzY2duRLg== X-Received: by 2002:a63:7418:: with SMTP id p24mr11327564pgc.196.1542916493237; Thu, 22 Nov 2018 11:54:53 -0800 (PST) X-Google-Smtp-Source: AFSGD/WEUJMuspibYXwL8umxLLQtb9rtJvPPHSgLoP/u7dMnkikO1PCvvP2EWhqVvAVS55/kPScG X-Received: by 2002:a63:7418:: with SMTP id p24mr11327534pgc.196.1542916492450; Thu, 22 Nov 2018 11:54:52 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1542916492; cv=none; d=google.com; s=arc-20160816; b=u/19n+u7xZQhquYffsLT87dirR3oKGKULvJh+Jv265ux8mEs7XCP9rPblXpz/zHNhB d28qQ1G/CVljd3Te8yw/mn3V0CfTxNhFEZXjwGOpveagtLC2yxXNlh6Mv6yHaakyf8Hw 67trHq1NP0XYGkmx1HafrwhbB42BcNjxtrJPVAm5R3mFtplYA27/2tUeeaOkRNhKi+Wi zsrt2YQ70zU1AaybjuergUfZW1oXDEFqr9IvkIV4Rw9oFHba0t7kfN6QVSjnJl8KgdDQ jNcF3/CFUPUykv30Iu+XcI8FYP4izy0H9Iz/XL3xR14chpULMBA/DEqUCg5xOxi6Yv5q XjRQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=2yY5eBgeLQ5vyKycEM63SfoZEzyeAKo8tsMENNgCu+A=; b=MebZcC1qQbYLnJ+/voiSVhdrrl4ubLx84tEQ/6aX8FopQ2s1AHk0cKRVCM+vmc6ZZK J/bvh8rbNGLipTNd4aKRA+tZ3oggPAP/qiDdogGt9O9Qzw9mjlJFSEggsAX9Tjy7PxxT o1vLV8ngXq2cme5OdRtxzJZ429hN6JeRlBND0pLlNTsSr+EfxZHugBkb7l/VIbQ/GXnW NipL80sXqP+R82aGkkh/oMFiNZp+WIRa6fSt5W/0dK5LM86SmgNuISEFxnMp/ujmI4Ov WQVutI+LgGHVo5OK2zbOXyXbXTTmWEKnUCv0MWh+FLC7TXY7O8FL7khTGsWUm4RaeBJZ 9AOQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Nus7n6ZQ; spf=pass (google.com: domain of sashal@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from mail.kernel.org (mail.kernel.org. [198.145.29.99]) by mx.google.com with ESMTPS id o22si41201070pgb.584.2018.11.22.11.54.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Nov 2018 11:54:52 -0800 (PST) Received-SPF: pass (google.com: domain of sashal@kernel.org designates 198.145.29.99 as permitted sender) client-ip=198.145.29.99; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Nus7n6ZQ; spf=pass (google.com: domain of sashal@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from sasha-vm.mshome.net (unknown [37.142.5.207]) (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 169E820672; Thu, 22 Nov 2018 19:54:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542916492; bh=y9AxcDCFbvc982k1P00ZUECBchNE/Mwbycwse3c4ZVY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nus7n6ZQurDFgxJm3Jzz8mFVVUlCsR9thWhTDeBT16jAiHcv5lgZrKeG7PzUDrLff jOgkqvNnriLj5bIRBsqndlZNZpi8A0R9wKZpP1I1t5IeGnOR8Agdsvfn2pzwtdUY3u Njk3VTNO5GK6noKdLFvS25X+aXDYldIIS9aZWamY= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Michal Hocko , Balbir Singh , Mel Gorman , Pavel Tatashin , Oscar Salvador , Mike Rapoport , Aaron Lu , Joonsoo Kim , Byoungyoung Lee , "Dae R. Jeong" , Andrew Morton , Linus Torvalds , Sasha Levin , linux-mm@kvack.org Subject: [PATCH AUTOSEL 4.19 36/36] mm, page_alloc: check for max order in hot path Date: Thu, 22 Nov 2018 14:52:40 -0500 Message-Id: <20181122195240.13123-36-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181122195240.13123-1-sashal@kernel.org> References: <20181122195240.13123-1-sashal@kernel.org> 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: X-Virus-Scanned: ClamAV using ClamSMTP From: Michal Hocko [ Upstream commit c63ae43ba53bc432b414fd73dd5f4b01fcb1ab43 ] Konstantin has noticed that kvmalloc might trigger the following warning: WARNING: CPU: 0 PID: 6676 at mm/vmstat.c:986 __fragmentation_index+0x54/0x60 [...] Call Trace: fragmentation_index+0x76/0x90 compaction_suitable+0x4f/0xf0 shrink_node+0x295/0x310 node_reclaim+0x205/0x250 get_page_from_freelist+0x649/0xad0 __alloc_pages_nodemask+0x12a/0x2a0 kmalloc_large_node+0x47/0x90 __kmalloc_node+0x22b/0x2e0 kvmalloc_node+0x3e/0x70 xt_alloc_table_info+0x3a/0x80 [x_tables] do_ip6t_set_ctl+0xcd/0x1c0 [ip6_tables] nf_setsockopt+0x44/0x60 SyS_setsockopt+0x6f/0xc0 do_syscall_64+0x67/0x120 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 the problem is that we only check for an out of bound order in the slow path and the node reclaim might happen from the fast path already. This is fixable by making sure that kvmalloc doesn't ever use kmalloc for requests that are larger than KMALLOC_MAX_SIZE but this also shows that the code is rather fragile. A recent UBSAN report just underlines that by the following report UBSAN: Undefined behaviour in mm/page_alloc.c:3117:19 shift exponent 51 is too large for 32-bit type 'int' CPU: 0 PID: 6520 Comm: syz-executor1 Not tainted 4.19.0-rc2 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xd2/0x148 lib/dump_stack.c:113 ubsan_epilogue+0x12/0x94 lib/ubsan.c:159 __ubsan_handle_shift_out_of_bounds+0x2b6/0x30b lib/ubsan.c:425 __zone_watermark_ok+0x2c7/0x400 mm/page_alloc.c:3117 zone_watermark_fast mm/page_alloc.c:3216 [inline] get_page_from_freelist+0xc49/0x44c0 mm/page_alloc.c:3300 __alloc_pages_nodemask+0x21e/0x640 mm/page_alloc.c:4370 alloc_pages_current+0xcc/0x210 mm/mempolicy.c:2093 alloc_pages include/linux/gfp.h:509 [inline] __get_free_pages+0x12/0x60 mm/page_alloc.c:4414 dma_mem_alloc+0x36/0x50 arch/x86/include/asm/floppy.h:156 raw_cmd_copyin drivers/block/floppy.c:3159 [inline] raw_cmd_ioctl drivers/block/floppy.c:3206 [inline] fd_locked_ioctl+0xa00/0x2c10 drivers/block/floppy.c:3544 fd_ioctl+0x40/0x60 drivers/block/floppy.c:3571 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0xb3c/0x1a30 block/ioctl.c:601 block_ioctl+0x105/0x150 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1c0/0x1150 fs/ioctl.c:687 ksys_ioctl+0x9e/0xb0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x7e/0xc0 fs/ioctl.c:707 do_syscall_64+0xc4/0x510 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Note that this is not a kvmalloc path. It is just that the fast path really depends on having sanitzed order as well. Therefore move the order check to the fast path. Link: http://lkml.kernel.org/r/20181113094305.GM15120@dhcp22.suse.cz Signed-off-by: Michal Hocko Reported-by: Konstantin Khlebnikov Reported-by: Kyungtae Kim Acked-by: Vlastimil Babka Cc: Balbir Singh Cc: Mel Gorman Cc: Pavel Tatashin Cc: Oscar Salvador Cc: Mike Rapoport Cc: Aaron Lu Cc: Joonsoo Kim Cc: Byoungyoung Lee Cc: "Dae R. Jeong" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/page_alloc.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3a4065312938..b721631d78ab 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4055,17 +4055,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, unsigned int cpuset_mems_cookie; int reserve_flags; - /* - * In the slowpath, we sanity check order to avoid ever trying to - * reclaim >= MAX_ORDER areas which will never succeed. Callers may - * be using allocators in order of preference for an area that is - * too large. - */ - if (order >= MAX_ORDER) { - WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); - return NULL; - } - /* * We also sanity check to catch abuse of atomic reserves being used by * callers that are not in atomic context. @@ -4359,6 +4348,15 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid, gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */ struct alloc_context ac = { }; + /* + * There are several places where we assume that the order value is sane + * so bail out early if the request is out of bound. + */ + if (unlikely(order >= MAX_ORDER)) { + WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); + return NULL; + } + gfp_mask &= gfp_allowed_mask; alloc_mask = gfp_mask; if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))