From patchwork Mon Nov 30 12:18:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yanan Wang X-Patchwork-Id: 11940321 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=-15.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,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 AAF4DC8300F for ; Mon, 30 Nov 2020 12:20:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2EAD2206D8 for ; Mon, 30 Nov 2020 12:20:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="qD6rRGxp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EAD2206D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IgQ6IR8R0/moeAokmgtuKlhf9mMGRJ0f3XVXzB6/VAI=; b=qD6rRGxpkJ+dK7dJGauY2i9ng Z4LbUFR8K6syqWMNMItZOLA9FeBS92vK5we7rhUJgCphOKUiZqK2/CdL2W7bXEwsGH2Nk4ojed2YQ JHTuMm/xSAH+I8Xm3u4uxyfLgCfhMTNH0oiL1fhDl+A3tJ5eUDdl+d/aTDX1YBMvW1L7zfp03wbj8 uTKejSDyGf+4qiqCI8SvxEIGOlxjt65vdzKuaDEyOHuJu8GiHbJLsJfEZk7XEoe0AtQFXrXyRFR0N gyCzcH/dz5l9HvjmSb4Al0Su7bktY2EKEBaAmwNA9BFw6phx3WbvDrQFAZldotoNncsPXvC2XpSfo 6Wf8pCbSA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kji9F-0005ft-Tr; Mon, 30 Nov 2020 12:19:17 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kji9C-0005em-6O for linux-arm-kernel@lists.infradead.org; Mon, 30 Nov 2020 12:19:15 +0000 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Cl45T31PPzLxpp; Mon, 30 Nov 2020 20:18:37 +0800 (CST) Received: from DESKTOP-TMVL5KK.china.huawei.com (10.174.186.123) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Mon, 30 Nov 2020 20:19:02 +0800 From: Yanan Wang To: , , Marc Zyngier , Catalin Marinas , Will Deacon , James Morse , "Julien Thierry" , Suzuki K Poulose , Gavin Shan , Quentin Perret Subject: [RFC PATCH 1/3] KVM: arm64: Fix possible memory leak in kvm stage2 Date: Mon, 30 Nov 2020 20:18:45 +0800 Message-ID: <20201130121847.91808-2-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20201130121847.91808-1-wangyanan55@huawei.com> References: <20201130121847.91808-1-wangyanan55@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.186.123] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201130_071914_745188_3CE26E6A X-CRM114-Status: GOOD ( 10.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lushenming@huawei.com, jiangkunkun@huawei.com, Yanan Wang , yezengruan@huawei.com, wangjingyi11@huawei.com, yuzenghui@huawei.com, wanghaibin.wang@huawei.com, zhukeqian1@huawei.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org When installing a new leaf pte onto an invalid ptep, we need to get_page(ptep). When just updating a valid leaf ptep, we shouldn't get_page(ptep). Incorrect page_count of translation tables might lead to memory leak, when unmapping a stage 2 memory range. Signed-off-by: Yanan Wang --- arch/arm64/kvm/hyp/pgtable.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 0271b4a3b9fe..696b6aa83faf 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -186,6 +186,7 @@ static bool kvm_set_valid_leaf_pte(kvm_pte_t *ptep, u64 pa, kvm_pte_t attr, return old == pte; smp_store_release(ptep, pte); + get_page(virt_to_page(ptep)); return true; } @@ -476,6 +477,7 @@ static bool stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, /* There's an existing valid leaf entry, so perform break-before-make */ kvm_set_invalid_pte(ptep); kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, addr, level); + put_page(virt_to_page(ptep)); kvm_set_valid_leaf_pte(ptep, phys, data->attr, level); out: data->phys += granule; @@ -512,7 +514,7 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, } if (stage2_map_walker_try_leaf(addr, end, level, ptep, data)) - goto out_get_page; + return 0; if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1)) return -EINVAL; @@ -536,9 +538,8 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, } kvm_set_table_pte(ptep, childp); - -out_get_page: get_page(page); + return 0; }