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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 3AC13C432BE for ; Wed, 1 Sep 2021 08:46:22 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 F37796103D for ; Wed, 1 Sep 2021 08:46:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F37796103D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4GzyMb4S1Bz2ymx for ; Wed, 1 Sep 2021 18:46:19 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.ru (client-ip=107.174.27.60; helo=ozlabs.ru; envelope-from=aik@ozlabs.ru; receiver=) Received: from ozlabs.ru (ozlabs.ru [107.174.27.60]) by lists.ozlabs.org (Postfix) with ESMTP id 4GzyM73T0hz2xKP for ; Wed, 1 Sep 2021 18:45:54 +1000 (AEST) Received: from fstn1-p1.ozlabs.ibm.com. (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id 4AD66AE801F8; Wed, 1 Sep 2021 04:45:18 -0400 (EDT) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH kernel] KVM: PPC: Book3S: Suppress warnings when allocating too big memory slots Date: Wed, 1 Sep 2021 18:45:12 +1000 Message-Id: <20210901084512.1658628-1-aik@ozlabs.ru> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , kvm-ppc@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" The userspace can trigger "vmalloc size %lu allocation failure: exceeds total pages" via the KVM_SET_USER_MEMORY_REGION ioctl. This silences the warning by checking the limit before calling vzalloc() and returns ENOMEM if failed. This does not call underlying valloc helpers as __vmalloc_node() is only exported when CONFIG_TEST_VMALLOC_MODULE and __vmalloc_node_range() is not exported at all. Spotted by syzkaller. Signed-off-by: Alexey Kardashevskiy --- arch/powerpc/kvm/book3s_hv.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 474c0cfde384..a59f1cccbcf9 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4830,8 +4830,12 @@ static int kvmppc_core_prepare_memory_region_hv(struct kvm *kvm, unsigned long npages = mem->memory_size >> PAGE_SHIFT; if (change == KVM_MR_CREATE) { - slot->arch.rmap = vzalloc(array_size(npages, - sizeof(*slot->arch.rmap))); + unsigned long cb = array_size(npages, sizeof(*slot->arch.rmap)); + + if ((cb >> PAGE_SHIFT) > totalram_pages()) + return -ENOMEM; + + slot->arch.rmap = vzalloc(cb); if (!slot->arch.rmap) return -ENOMEM; } -- 2.30.2