From nobody Tue Sep 16 13:48:06 2025 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 E1344C3DA7D for ; Tue, 3 Jan 2023 06:30:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232883AbjACGab (ORCPT ); Tue, 3 Jan 2023 01:30:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230107AbjACGa2 (ORCPT ); Tue, 3 Jan 2023 01:30:28 -0500 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA49ACE37 for ; Mon, 2 Jan 2023 22:30:27 -0800 (PST) Received: by mail-pf1-x42d.google.com with SMTP id c9so15000176pfj.5 for ; Mon, 02 Jan 2023 22:30:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=IH4BnFmj51xja43rQ2VjV2A7Vl5bq18SZUAgL2EcwnI=; b=TG8uvyWlWw/f/acMw9cbu5au61WMfhj8SQ7FwLvxR65sqsYZBrZeJ84HJaB1uTlkJL NjKW3hoU0GcIiCuaxhYad+YSh6y8IxPDZsTYtz7rjBw5PGyuCpsS6al8/MpbgN0ZcJLJ f88f2MFNLsumloslDC9abPso5qnjumuUgJm8gVlEsK/WS9uv28IZhOLXdwC54bcSLGsx PqxZZ1FK2Lacldkq5OtLbraJqwV9ht6pZiE6vLz7JKYvU0RMFEvhq/nSEVE+5hmPHNvl 874ZBFtjftFatmgPEAof5bKW7H8DotegkmfFt/Hnwa6ydCivHzy46tLoyJTNJaFjfLWZ zGSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=IH4BnFmj51xja43rQ2VjV2A7Vl5bq18SZUAgL2EcwnI=; b=pfq7ejh6rLiBjC8zByKiV43lbphcbMwUYfkX4q4UO/f8hrpL24NFCXMvZekV7yFLta J8QtXm2yX5Zx6NbifZU2aoSxkUXEtAG5JhVeQlnUuJOS6uQy4TdfLtonc1ZuVr5Gtw7w SQKsphsUu6BO9Eci0la0OweYZhtmH472AsOGQe2XWsBxIRORhzN+cB7ZMxupXhHBErtt J+RpVAeedzAa/qsIxoCL8XsZZyjprlMXHc03GjlylJ4EwWkCpoiIsVKEI2OPkmq0G3R3 Ttb04Lt5FWolJoeWg3E7h6IzMDUcwy09TktQonZ7oTTed5/l1FIN8/xcuMbDrFDcXk6r j0cQ== X-Gm-Message-State: AFqh2kqYtVECpsgjM+s2l512BBqA/sZK9DkLYVfwQ8iano4HjKxsoxG7 78NiNGKI7mj0dD8y98IYHwQ= X-Google-Smtp-Source: AMrXdXuB8TRSOt5N1YqvE+OSqTWyWFvhKTUMq1KEyXVklZBiK31z6i7whkRLrLYws9KRNGMhpo6u6Q== X-Received: by 2002:a05:6a00:88a:b0:581:19ed:78b9 with SMTP id q10-20020a056a00088a00b0058119ed78b9mr38707011pfj.2.1672727427390; Mon, 02 Jan 2023 22:30:27 -0800 (PST) Received: from localhost.localdomain ([202.120.234.246]) by smtp.googlemail.com with ESMTPSA id i127-20020a626d85000000b00581a156b920sm10418848pfc.132.2023.01.02.22.30.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Jan 2023 22:30:26 -0800 (PST) From: Miaoqian Lin To: Joerg Roedel , Will Deacon , Robin Murphy , Lu Baolu , Eric Auger , Jason Gunthorpe , Kevin Tian , iommu@lists.linux.dev, linux-kernel@vger.kernel.org Cc: linmq006@gmail.com Subject: [PATCH] iommu: Fix refcount leak in iommu_device_claim_dma_owner Date: Tue, 3 Jan 2023 10:30:17 +0400 Message-Id: <20230103063017.4022393-1-linmq006@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" iommu_group_get() returns the group with the reference incremented. Also an empty @owner is a more serious problem than refcount leak. Move iommu_group_get() after owner check to fix the refcount leak. Fixes: 89395ccedbc1 ("iommu: Add device-centric DMA ownership interfaces") Signed-off-by: Miaoqian Lin Reviewed-by: Jason Gunthorpe --- changes in v2: - Remove set NULL to group as suggested by Baolu Lu. - Update commit message according to Lu's explanation. --- drivers/iommu/iommu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index de91dd88705b..5f6a85aea501 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3185,14 +3185,16 @@ EXPORT_SYMBOL_GPL(iommu_group_claim_dma_owner); */ int iommu_device_claim_dma_owner(struct device *dev, void *owner) { - struct iommu_group *group =3D iommu_group_get(dev); + struct iommu_group *group; int ret =3D 0; =20 - if (!group) - return -ENODEV; if (WARN_ON(!owner)) return -EINVAL; =20 + group =3D iommu_group_get(dev); + if (!group) + return -ENODEV; + mutex_lock(&group->mutex); if (group->owner_cnt) { if (group->owner !=3D owner) { --=20 2.25.1