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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6AD83C77B73 for ; Wed, 19 Apr 2023 10:18:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=JGngmgifi1psG7lxJLys9bV0YDChVtv4Z3dhiyU+gws=; b=aO3YY8r/uLQlsl bsbWtqDLa15bPdefNg4Vqj9q9po4Wuxm4KSl4Zumzmd1npeG316Y3DL1AteT+rJuhpb29aAWEs5ta ly7op61gBngfrW3SMl+GpEXzF1t3n+awEjmah+ICJR1FisoefKxXz8UuA/QFdsJuAFEb8BAb0dFqq 721FbSZP5myNev5JSufVmym9jq6Huph6AtbURUKNc8jYrOgOA4++9oJQRR+Tu2FdVnsFuqQeE3zlE YAi6UObL0zn9iqr+Dese728Tp6IeEN8RLe2bOwChKz4UtKruYMkARAgimaQoR0LzaHRdMPt83jiRE +mTO3donYagILRGTxfgw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pp4t0-004sGC-2t; Wed, 19 Apr 2023 10:18:02 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pp4sw-004sEs-2x for linux-arm-kernel@lists.infradead.org; Wed, 19 Apr 2023 10:18:00 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 55BE0106F; Wed, 19 Apr 2023 03:18:40 -0700 (PDT) Received: from [10.57.20.93] (unknown [10.57.20.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BFBE23F6C4; Wed, 19 Apr 2023 03:17:53 -0700 (PDT) Message-ID: <5ab50a0f-fb75-7435-4b59-98adcc223dfd@arm.com> Date: Wed, 19 Apr 2023 11:17:51 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH v2] KVM: arm64: Fix buffer overflow in kvm_arm_set_fw_reg() Content-Language: en-GB To: Dan Carpenter , Andre Przywara Cc: Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Eric Auger , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kernel-janitors@vger.kernel.org References: <4efbab8c-640f-43b2-8ac6-6d68e08280fe@kili.mountain> From: Steven Price In-Reply-To: <4efbab8c-640f-43b2-8ac6-6d68e08280fe@kili.mountain> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230419_031758_998120_5392FCD2 X-CRM114-Status: GOOD ( 16.34 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 19/04/2023 11:16, Dan Carpenter wrote: > The KVM_REG_SIZE() comes from the ioctl and it can be a power of two > between 0-32768 but if it is more than sizeof(long) this will corrupt > memory. > > Fixes: 99adb567632b ("KVM: arm/arm64: Add save/restore support for firmware workaround state") > Signed-off-by: Dan Carpenter Reviewed-by: Steven Price Thanks, Steve > --- > v2: The original patch was okay but checking for != sizeof(val) is > stricter and more Obviously Correct[tm]. Return -ENOENT instead of > -EINVAL in case future ioctls are added which take a different size. > > arch/arm64/kvm/hypercalls.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c > index 2e16fc7b31bf..7fb4df0456de 100644 > --- a/arch/arm64/kvm/hypercalls.c > +++ b/arch/arm64/kvm/hypercalls.c > @@ -544,6 +544,8 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > u64 val; > int wa_level; > > + if (KVM_REG_SIZE(reg->id) != sizeof(val)) > + return -ENOENT; > if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id))) > return -EFAULT; > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel