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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BA4AC433EF for ; Tue, 7 Jun 2022 19:21:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355819AbiFGTVa (ORCPT ); Tue, 7 Jun 2022 15:21:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352548AbiFGSbE (ORCPT ); Tue, 7 Jun 2022 14:31:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E678A146432; Tue, 7 Jun 2022 10:56:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9F87A61882; Tue, 7 Jun 2022 17:56:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A974FC34115; Tue, 7 Jun 2022 17:56:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654624588; bh=O5JT5+VvzEisjjF0FEtEb5N0G8F6D2H0gpnUHuMuMkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JwdGA1HPSzRNvE8irfs71tnidbDrHJ/UehwrsUKLgqNR6Qw0f4S+SQ4l8ATAKgAQD e8H9AH0UNs67HFn63QPFShvoYMdMmQTZiG3+pQbxkbHhW5W0jzE/aG5FRVj93q2zvU JgCbji3jxt99DV1CgP7frljZYX/KaXbSBRpTiFmw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Robin Murphy , Christoph Hellwig , David Rientjes , Sasha Levin Subject: [PATCH 5.15 380/667] dma-direct: dont over-decrypt memory Date: Tue, 7 Jun 2022 19:00:45 +0200 Message-Id: <20220607164946.146389737@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164934.766888869@linuxfoundation.org> References: <20220607164934.766888869@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Robin Murphy [ Upstream commit 4a37f3dd9a83186cb88d44808ab35b78375082c9 ] The original x86 sev_alloc() only called set_memory_decrypted() on memory returned by alloc_pages_node(), so the page order calculation fell out of that logic. However, the common dma-direct code has several potential allocators, not all of which are guaranteed to round up the underlying allocation to a power-of-two size, so carrying over that calculation for the encryption/decryption size was a mistake. Fix it by rounding to a *number* of pages, rather than an order. Until recently there was an even worse interaction with DMA_DIRECT_REMAP where we could have ended up decrypting part of the next adjacent vmalloc area, only averted by no architecture actually supporting both configs at once. Don't ask how I found that one out... Fixes: c10f07aa27da ("dma/direct: Handle force decryption for DMA coherent buffers in common code") Signed-off-by: Robin Murphy Signed-off-by: Christoph Hellwig Acked-by: David Rientjes Signed-off-by: Sasha Levin --- kernel/dma/direct.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 8e24455dd236..854d6df969de 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -79,7 +79,7 @@ static int dma_set_decrypted(struct device *dev, void *vaddr, size_t size) { if (!force_dma_unencrypted(dev)) return 0; - return set_memory_decrypted((unsigned long)vaddr, 1 << get_order(size)); + return set_memory_decrypted((unsigned long)vaddr, PFN_UP(size)); } static int dma_set_encrypted(struct device *dev, void *vaddr, size_t size) @@ -88,7 +88,7 @@ static int dma_set_encrypted(struct device *dev, void *vaddr, size_t size) if (!force_dma_unencrypted(dev)) return 0; - ret = set_memory_encrypted((unsigned long)vaddr, 1 << get_order(size)); + ret = set_memory_encrypted((unsigned long)vaddr, PFN_UP(size)); if (ret) pr_warn_ratelimited("leaking DMA memory that can't be re-encrypted\n"); return ret; -- 2.35.1