From nobody Fri Dec 19 12:06:29 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5C5F194AEF; Tue, 27 Aug 2024 08:48:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724748492; cv=none; b=gwW3dAqE5miQh3sdQhvVmgmx7ZX43As76ULDCFjvrzIoAwvvVmdqGMk39uXHjq1IEbXhSn7C1MM4lfY+urJhZSpD+xFmvdCN3piwM97COWubwrPJDPnVxzmey2YTnj/0ZMC/tMJTIV5rAWFj3Brg7y5Fb5Gudqaxv6H8OtjiGuI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724748492; c=relaxed/simple; bh=TwDf773hXhfsiYVvV+dls2u7pbgcM7zdEocdZh2VUzM=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=gW0fDDuq6dsczzXl6kEh68ZlYOGzlktu45nCCvZKFhHnmNEAgIWPdi6+vUeFOhQQnmGKYxBQ2eBPnlRaz+7LTzCPYLYA6jPluMuuUBxpP1NWNwRFJZs1cumV/Ba8jNn//zd0XeCXZwND84+VX2ziNQX0lMnCD6/4mJSkfoO951A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=P7JnW5fk; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=yDHclUla; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="P7JnW5fk"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="yDHclUla" Date: Tue, 27 Aug 2024 08:48:05 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1724748486; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+9m7zAe/oM8NIYedLT9hEyQfOwjL4BIqPbJsnLJv+Bc=; b=P7JnW5fkM+2LHwb6kDXdptcVVMiWOv2CkVTKDAkQ+NG0r6YerCYj9AKC6lEw62cCV+nw7o 2r/cxO/EUnWY6eA3VrAD67baxW2x6cyMkB5SsFm3Fzlc+c4SDIyo5Ru9HMxJGntASeRatA W3ovQAxR/z6CNEvZO9jydY2ovPyvjQcsqMS5mG+TTbrkWAvaJzF+NzUTAGjrsl90JEOdDY m1ESH1J23OYq+PJL+TmSLDsRP+19AcppdlPgRkxA9TGuJdgBT1AZoUZmZlHCFH78u/KaY+ Guu2iWqVPOvWF7St4RpF5Cr9Q5eNifegi2iXNurnoLawLKcNXCJQ1zN/JH0neQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1724748486; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+9m7zAe/oM8NIYedLT9hEyQfOwjL4BIqPbJsnLJv+Bc=; b=yDHclUlawN3VbE0zKpfq4Xfp/XlJAjNBZWeT7wBA1ZJrObYz4a5a0xbOVVTNGsiGu/OpA6 eS7QftGg2nLG8ADA== From: "tip-bot2 for Nikunj A Dadhania" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/sev] virt: sev-guest: Ensure the SNP guest messages do not exceed a page Cc: Tom Lendacky , Nikunj A Dadhania , "Borislav Petkov (AMD)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240731150811.156771-5-nikunj@amd.com> References: <20240731150811.156771-5-nikunj@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <172474848574.2215.3184921045455646454.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/sev branch of tip: Commit-ID: 2b9ac0b84c2cae91bbaceab62df4de6d503421ec Gitweb: https://git.kernel.org/tip/2b9ac0b84c2cae91bbaceab62df4de6d5= 03421ec Author: Nikunj A Dadhania AuthorDate: Wed, 31 Jul 2024 20:37:55 +05:30 Committer: Borislav Petkov (AMD) CommitterDate: Tue, 27 Aug 2024 10:35:38 +02:00 virt: sev-guest: Ensure the SNP guest messages do not exceed a page Currently, struct snp_guest_msg includes a message header (96 bytes) and a payload (4000 bytes). There is an implicit assumption here that the SNP message header will always be 96 bytes, and with that assumption the payload array size has been set to 4000 bytes - a magic number. If any new member is added to the SNP message header, the SNP guest message will span more than a page. Instead of using a magic number for the payload, declare struct snp_guest_msg in a way that payload plus the message header do not exceed a page. [ bp: Massage. ] Suggested-by: Tom Lendacky Signed-off-by: Nikunj A Dadhania Signed-off-by: Borislav Petkov (AMD) Acked-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240731150811.156771-5-nikunj@amd.com --- arch/x86/include/asm/sev.h | 2 +- drivers/virt/coco/sev-guest/sev-guest.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 79bbe2b..ee34ab0 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -164,7 +164,7 @@ struct snp_guest_msg_hdr { =20 struct snp_guest_msg { struct snp_guest_msg_hdr hdr; - u8 payload[4000]; + u8 payload[PAGE_SIZE - sizeof(struct snp_guest_msg_hdr)]; } __packed; =20 struct sev_guest_platform_data { diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/se= v-guest/sev-guest.c index 3b76cbf..89754b0 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -1092,6 +1092,8 @@ static int __init sev_guest_probe(struct platform_dev= ice *pdev) void __iomem *mapping; int ret; =20 + BUILD_BUG_ON(sizeof(struct snp_guest_msg) > PAGE_SIZE); + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) return -ENODEV;