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 D05CE29E1C5; Fri, 29 Mar 2024 12:46:58 +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=1711716418; cv=none; b=PN3Q+Y9DtrkEG9xcJ3UnthjlDV+osA4RKvQ16jbY1Ona4T0kVgaQi8cVPhr9fUu9Z5aH0aSQdvB0DhdMN+Aq7d6g/ZvUQZ/F+FnPIBu3nzmYENP8YjLlpiaedjAqB1sDC84PSPWgWlBvX0L3u0KPO2BBdmPVkjGypCDVbc83Vxk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711716418; c=relaxed/simple; bh=k817z/wiq1ZdzswJB0vLMttW1moO1DxXigH8OAcdidA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VJ5GPwFXsooIz0OxfD0VWXxgkolinqC2SDnOcvCdG2H5LlKoDwrUICZJQjH9R1rOGtAuxsKqkG4DbEq+vnHW0cqc7KaUNv/CfKHfwLqXD01pM1Oloe6nW+p3+i/S/e+avyBxh1XnyPHP6Te7wB68z/m6lSI/i7zyRjfbmZqN4GE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QaNL0ut3; 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="QaNL0ut3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4D10C43390; Fri, 29 Mar 2024 12:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711716418; bh=k817z/wiq1ZdzswJB0vLMttW1moO1DxXigH8OAcdidA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QaNL0ut39GfeY9cNKBFVDg1JkZr6u0+tgt9hUplhYQXVZnchEkSb9NA77RQa4UXFF Ve3sX28q3dM2j4oq5VwgE3XfNGRb0GOLCDQynpb+o9S5RBbyR+VuLJwJzzWA+Eha3J Qc1bPAGP45gHjuNo6hoX7P3O1n6iwZrAlosdbZCTwuMn3ryuJikpmRlZntEoM4vrcR OurigfXh+6e4eavFjZ5IQoeo71oxtL6L8BYSdAGgLK04WHHbvzfA+77J+knaAjeSjE QpNhsr5K2KfUEL0wT9/WX5MAj4O8Psthk4Uu6yH8jd1cnU0sG+MBeDvuUivf6MgqUS 5U1KruezeiU7g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Rick Edgecombe , Christoph Hellwig , Sasha Levin , m.szyprowski@samsung.com, iommu@lists.linux.dev Subject: [PATCH AUTOSEL 6.1 28/52] dma-direct: Leak pages on dma_set_decrypted() failure Date: Fri, 29 Mar 2024 08:45:22 -0400 Message-ID: <20240329124605.3091273-28-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240329124605.3091273-1-sashal@kernel.org> References: <20240329124605.3091273-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.83 Content-Transfer-Encoding: 8bit From: Rick Edgecombe [ Upstream commit b9fa16949d18e06bdf728a560f5c8af56d2bdcaf ] On TDX it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. DMA could free decrypted/shared pages if dma_set_decrypted() fails. This should be a rare case. Just leak the pages in this case instead of freeing them. Signed-off-by: Rick Edgecombe Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- kernel/dma/direct.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 63859a101ed83..d4215739efc71 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -296,7 +296,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, } else { ret = page_address(page); if (dma_set_decrypted(dev, ret, size)) - goto out_free_pages; + goto out_leak_pages; } memset(ret, 0, size); @@ -317,6 +317,8 @@ void *dma_direct_alloc(struct device *dev, size_t size, out_free_pages: __dma_direct_free_pages(dev, page, size); return NULL; +out_leak_pages: + return NULL; } void dma_direct_free(struct device *dev, size_t size, @@ -379,12 +381,11 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, ret = page_address(page); if (dma_set_decrypted(dev, ret, size)) - goto out_free_pages; + goto out_leak_pages; memset(ret, 0, size); *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); return page; -out_free_pages: - __dma_direct_free_pages(dev, page, size); +out_leak_pages: return NULL; } -- 2.43.0