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 02AB41DDFA; Fri, 26 Jan 2024 15:20:07 +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=1706282408; cv=none; b=VJvzAe6gxItBJJo6toVpA3a9YMw3fEanxDP2/a2HJtRgMPskbrjll5I9r5lrqbUzNykPEfO4EAJmCpxklzO9ZX/3dgAvu2xRS/s+1lfOla8Laq9chGVBHfhPUs9XyAO1svafER5hJggVsHMtHi2y+MVnBkP5BfFsK/ALWTKJSTI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706282408; c=relaxed/simple; bh=t6tVLr88lHsU9jH1kug5zqXilXYDgE+NKYSfWIblYK8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=DSeDBNScrvRrGbDWXU5s8GDBDTsHlL9nAXZVRYOlqkHmpM3w8Df551HK7rh/HbdznTxYdRtDfMeHqAB1WwhOlOYUIUWtHjTxeGwnCaW/eXzG55xNEuy6DO6GoWgufLkvM8WaqDVXwk5YMaEN5KEiKFO7yqjOepUOUc0mEa/Rm8M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=beJRQC/+; 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="beJRQC/+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2CC3C433A6; Fri, 26 Jan 2024 15:20:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706282407; bh=t6tVLr88lHsU9jH1kug5zqXilXYDgE+NKYSfWIblYK8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=beJRQC/+Q3Kb8nzVOp4Raf61+0zFGFzMo1iG2HHlKGag0edBFTqYDcUugDYzgdoUZ Vj3oh4+rEQYj2Cdr2o1HB/NnvuWtoSEgdoJMi6WpxTNc060GdrNwImsdDxPprx29+7 RGQAacXMLvhD6bx6aObOjzotA1v/Dxb71pglXI9vlVkgtZhjdt+8qIcEqaV83sQz3C 97JwQZ6YaBweaHAlZra27T7ISP5TuBq8qzbjjCbj4HJWw3kJY809rZZeViYXzJSoJJ ucptjt+b2tTAbFUnfUybnaYry1UVlR9UOeYO+gKIlajsg+BP+gh2+CND9XT97gGUp8 0TY1PprbfoNhw== From: Will Deacon To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, Will Deacon , iommu@lists.linux.dev, Christoph Hellwig , Marek Szyprowski , Robin Murphy , Petr Tesarik , Dexuan Cui Subject: [PATCH 2/2] swiotlb: Enforce page alignment in swiotlb_alloc() Date: Fri, 26 Jan 2024 15:19:56 +0000 Message-Id: <20240126151956.10014-3-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240126151956.10014-1-will@kernel.org> References: <20240126151956.10014-1-will@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When allocating pages from a restricted DMA pool in swiotlb_alloc(), the buffer address is blindly converted to a 'struct page *' that is returned to the caller. In the unlikely event of an allocation bug, page-unaligned addresses are not detected and slots can silently be double-allocated. Add a simple check of the buffer alignment in swiotlb_alloc() to make debugging a little easier if something has gone wonky. Cc: Christoph Hellwig Cc: Marek Szyprowski Cc: Robin Murphy Cc: Petr Tesarik Cc: Dexuan Cui Signed-off-by: Will Deacon --- kernel/dma/swiotlb.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 25febb9e670c..92433ea9f2d2 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -1647,6 +1647,12 @@ struct page *swiotlb_alloc(struct device *dev, size_t size) return NULL; tlb_addr = slot_addr(pool->start, index); + if (!PAGE_ALIGNED(tlb_addr)) { + dev_WARN_ONCE(dev, 1, "Cannot return 'struct page *' for non page-aligned swiotlb addr 0x%pa.\n", + &tlb_addr); + swiotlb_release_slots(dev, tlb_addr); + return NULL; + } return pfn_to_page(PFN_DOWN(tlb_addr)); } -- 2.43.0.429.g432eaa2c6b-goog