From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A38551CF7AD for ; Wed, 2 Oct 2024 12:24:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727871885; cv=none; b=A+1zUOOAm8mxvUQiIEAe5hREJGU4qja+o6N65fKps7ENwVgHYax4qyyLOtNc5rEegZ5u0K3VJPKs/ydGxOK00QNaFv6k/wR/OVE+6XsrVX7L3684duz6+dBDJnJaPs7wORD+IVPKe4L32wbVIExrmkIuOxA5UBDQVzZMcm2SFVg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727871885; c=relaxed/simple; bh=X3e9kRULRjZb9TGN3ZNhhoFjOUtuHwcyScRt2yxCU0s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OpS24G1nx3zh+HfUfZO9cb0alqSnutse4lbCD+JeSF4EjpNYRMptBLe8U7yBj+eo767B/58hX+wBWHdPydGo/jwNy8UCkDx5NRX7ZRDF+RR0Wf92awqPyHBAYUrsBH8lkZkUyNCsM+Ja0CiXaVLeqp/gyaPeygsn5x4Dv491w7M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qOihqfzn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qOihqfzn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEE21C4CED4; Wed, 2 Oct 2024 12:24:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727871885; bh=X3e9kRULRjZb9TGN3ZNhhoFjOUtuHwcyScRt2yxCU0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qOihqfznBKgQlavQ2mQ3heVvU/sWBs+ZhFrJHxsQI3G8uJV8XqLzVB6kllqMYC+cx HcmgQeYCHKcwUAjdiPgo0H/tqhhby/qUP51qZQJxx8k76sXfs0lzotnCA7b9i5WIZg zafy2bU6zovI/aTu2kOUShbNGNKeZll4vbyDxg5z7qk69VM6moV3jzqRCbtz/ouaFW pyLe+OSZxz0HUjqWdgY6+Q2BgsHwz0J1qKOmXkE6YKQhQHjXmwVvK0UlauvVJGQIxW fWPFTHeRRrLYKmAuULALKRR6OX8WXxPO+H/v7jfHh/l17qKlMtP4P5wobramJnACwZ sDuOLrvUSwvlA== From: "Alexey Gladkov (Intel)" To: stable@vger.kernel.org Cc: "Alexey Gladkov (Intel)" , Dave Hansen , "Kirill A. Shutemov" Subject: [PATCH 6.6.y] x86/tdx: Fix "in-kernel MMIO" check Date: Wed, 2 Oct 2024 14:23:59 +0200 Message-ID: <20241002122359.83485-1-legion@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <2024100100-emperor-thespian-397f@gregkh> References: <2024100100-emperor-thespian-397f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit TDX only supports kernel-initiated MMIO operations. The handle_mmio() function checks if the #VE exception occurred in the kernel and rejects the operation if it did not. However, userspace can deceive the kernel into performing MMIO on its behalf. For example, if userspace can point a syscall to an MMIO address, syscall does get_user() or put_user() on it, triggering MMIO #VE. The kernel will treat the #VE as in-kernel MMIO. Ensure that the target MMIO address is within the kernel before decoding instruction. Fixes: 31d58c4e557d ("x86/tdx: Handle in-kernel MMIO") Signed-off-by: Alexey Gladkov (Intel) Signed-off-by: Dave Hansen Reviewed-by: Kirill A. Shutemov Acked-by: Dave Hansen Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/565a804b80387970460a4ebc67c88d1380f61ad1.1726237595.git.legion%40kernel.org (cherry picked from commit d4fc4d01471528da8a9797a065982e05090e1d81) Signed-off-by: Alexey Gladkov (Intel) --- arch/x86/coco/tdx/tdx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 006041fbb65f..905ac8a3f716 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -14,6 +14,7 @@ #include #include #include +#include /* MMIO direction */ #define EPT_READ 0 @@ -405,6 +406,11 @@ static int handle_mmio(struct pt_regs *regs, struct ve_info *ve) return -EINVAL; } + if (!fault_in_kernel_space(ve->gla)) { + WARN_ONCE(1, "Access to userspace address is not supported"); + return -EINVAL; + } + /* * Reject EPT violation #VEs that split pages. * -- 2.46.2