From patchwork Tue Dec 20 13:06:59 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 707421 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3tjdP45YGCz9t15 for ; Wed, 21 Dec 2016 00:07:36 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934016AbcLTNHU (ORCPT ); Tue, 20 Dec 2016 08:07:20 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:33300 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756614AbcLTNHL (ORCPT ); Tue, 20 Dec 2016 08:07:11 -0500 Received: by mail-wm0-f67.google.com with SMTP id u144so24210888wmu.0; Tue, 20 Dec 2016 05:07:10 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=nIrGlPjyaiFcFw2q9zKn4FcNrJ78jQmBB+0Yz1Jz7M8=; b=rLuTtYw/I/RUu2L/qRUyEgzHet5cQipa2YNaNKCCidsptaH4FQ91Wl4xqXzpRQu9wx N2nLegWNV2dshCyqSAQ8qDxWLggOlWq/hre8VgtUiY6E+3SOOKQGzHbJizccNxlIrR1L PHUZYmcm2LRvOOZ/xzVacK9qW0xLUA8CQ/FDa8HHfL15BY9/u0WamEo4IMaaCXAMsw8S ja4TiP9T4ucWx+JW0XsfuLEdlDq+LusU8krHdY3ssr1uIWQtn9asPlMypnYlQv9dUK19 ljmc0Sej16f1/MxEfdnbr7JD4IgkMssoOtz7XK6T6RA1gnYCZjqDghZWb0oSmwqrWHG9 IVwQ== X-Gm-Message-State: AIkVDXLvL0pFmGUvc+nsXoMCD+FW38cv7gGn8u0Z1wbXeGCs5KKwX41EIz2IiTd8qtsQBg== X-Received: by 10.28.27.133 with SMTP id b127mr1943736wmb.59.1482239229721; Tue, 20 Dec 2016 05:07:09 -0800 (PST) Received: from tiehlicka.suse.cz ([213.151.95.130]) by smtp.gmail.com with ESMTPSA id n5sm21977804wmf.0.2016.12.20.05.07.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Dec 2016 05:07:09 -0800 (PST) From: Michal Hocko To: Andrew Morton Cc: Cristopher Lameter , Alexei Starovoitov , Andrey Konovalov , netdev@vger.kernel.org, , LKML , Michal Hocko Subject: [PATCH 2/2] bpf: do not use KMALLOC_SHIFT_MAX Date: Tue, 20 Dec 2016 14:06:59 +0100 Message-Id: <20161220130659.16461-3-mhocko@kernel.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161220130659.16461-1-mhocko@kernel.org> References: <20161220130659.16461-1-mhocko@kernel.org> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Michal Hocko 01b3f52157ff ("bpf: fix allocation warnings in bpf maps and integer overflow") has added checks for the maximum allocateable size. It (ab)used KMALLOC_SHIFT_MAX for that purpose. While this is not incorrect it is not very clean because we already have KMALLOC_MAX_SIZE for this very reason so let's change both checks to use KMALLOC_MAX_SIZE instead. The original motivation for using KMALLOC_SHIFT_MAX was to work around an incorrect KMALLOC_MAX_SIZE which could lead to allocation warnings but it is no longer needed since "slab: make sure that KMALLOC_MAX_SIZE will fit into MAX_ORDER". Signed-off-by: Michal Hocko Acked-by: Christoph Lameter --- kernel/bpf/arraymap.c | 2 +- kernel/bpf/hashtab.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index a2ac051c342f..229a5d5df977 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -56,7 +56,7 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr) attr->value_size == 0 || attr->map_flags) return ERR_PTR(-EINVAL); - if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1)) + if (attr->value_size > KMALLOC_MAX_SIZE) /* if value_size is bigger, the user space won't be able to * access the elements. */ diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index ad1bc67aff1b..c5ec7dc71c84 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -181,7 +181,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) */ goto free_htab; - if (htab->map.value_size >= (1 << (KMALLOC_SHIFT_MAX - 1)) - + if (htab->map.value_size >= KMALLOC_MAX_SIZE - MAX_BPF_STACK - sizeof(struct htab_elem)) /* if value_size is bigger, the user space won't be able to * access the elements via bpf syscall. This check also makes