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 1C849328B58; Fri, 9 Jan 2026 12:13:28 +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=1767960808; cv=none; b=RTxEJyw/C8kcYh6zhCPHZrrdbbl9+jCccWTHmfqNJxmDlrhY6JBFr23bXbO/Mb8gFxoUE8ACdysik6yQ+Iy8XBUaiwI5sWELfZVGmJcMnMSEEiCRnTAUUXxfOYMWs5W9Wwdjsf2tInlymeBJmPzBfYhcG/12Ry4A3+shVFJzEjM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767960808; c=relaxed/simple; bh=L/UGCnH3F4JzhcJuKRcqUH/Mf8lNvZQxKEMcetj1zP4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KrMWhs3CmASSe3OK01oaCltvK8F68YQZjc486fE5iwOD5aZkAVXY0oqweZTmfO4WGclbS6X1ttoMVZbWbt6HCWIvqcYtM70XXsj4cibBDLqqv4Hn5Ru+QJfNmoD+70vRov6zfjW8cV84Qpfh44hpIidvP50F+NEXWco//apgWYQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FMYrQg4O; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FMYrQg4O" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C501C4CEF1; Fri, 9 Jan 2026 12:13:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767960808; bh=L/UGCnH3F4JzhcJuKRcqUH/Mf8lNvZQxKEMcetj1zP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FMYrQg4O3PozPfvrCLOFwr8+QM9wk7utt9tfntgjGKZHpHv83LBdStUy0AVugTipl B7Fa+Z9Yjlvtl7KAB7ljFWe10l9T0CN3YrsGovfJPr9+M4BP99PFeBE+f42TIfRwda j5rKsCt4c6fFaYkb8NzqUFFV0l2eW3DyoYHVcyEk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yong Wu , Robin Murphy , Johan Hovold , AngeloGioacchino Del Regno , Joerg Roedel Subject: [PATCH 6.6 500/737] iommu/mediatek: fix use-after-free on probe deferral Date: Fri, 9 Jan 2026 12:40:39 +0100 Message-ID: <20260109112152.803035225@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260109112133.973195406@linuxfoundation.org> References: <20260109112133.973195406@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit de83d4617f9fe059623e97acf7e1e10d209625b5 upstream. The driver is dropping the references taken to the larb devices during probe after successful lookup as well as on errors. This can potentially lead to a use-after-free in case a larb device has not yet been bound to its driver so that the iommu driver probe defers. Fix this by keeping the references as expected while the iommu driver is bound. Fixes: 26593928564c ("iommu/mediatek: Add error path for loop of mm_dts_parse") Cc: stable@vger.kernel.org Cc: Yong Wu Acked-by: Robin Murphy Signed-off-by: Johan Hovold Reviewed-by: Yong Wu Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/mtk_iommu.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -1196,16 +1196,19 @@ static int mtk_iommu_mm_dts_parse(struct } component_match_add(dev, match, component_compare_dev, &plarbdev->dev); - platform_device_put(plarbdev); } - if (!frst_avail_smicomm_node) - return -EINVAL; + if (!frst_avail_smicomm_node) { + ret = -EINVAL; + goto err_larbdev_put; + } pcommdev = of_find_device_by_node(frst_avail_smicomm_node); of_node_put(frst_avail_smicomm_node); - if (!pcommdev) - return -ENODEV; + if (!pcommdev) { + ret = -ENODEV; + goto err_larbdev_put; + } data->smicomm_dev = &pcommdev->dev; link = device_link_add(data->smicomm_dev, dev, @@ -1213,7 +1216,8 @@ static int mtk_iommu_mm_dts_parse(struct platform_device_put(pcommdev); if (!link) { dev_err(dev, "Unable to link %s.\n", dev_name(data->smicomm_dev)); - return -EINVAL; + ret = -EINVAL; + goto err_larbdev_put; } return 0; @@ -1385,8 +1389,12 @@ out_sysfs_remove: iommu_device_sysfs_remove(&data->iommu); out_list_del: list_del(&data->list); - if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_MM)) + if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_MM)) { device_link_remove(data->smicomm_dev, dev); + + for (i = 0; i < MTK_LARB_NR_MAX; i++) + put_device(data->larb_imu[i].dev); + } out_runtime_disable: pm_runtime_disable(dev); return ret; @@ -1406,6 +1414,9 @@ static void mtk_iommu_remove(struct plat if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_MM)) { device_link_remove(data->smicomm_dev, &pdev->dev); component_master_del(&pdev->dev, &mtk_iommu_com_ops); + + for (i = 0; i < MTK_LARB_NR_MAX; i++) + put_device(data->larb_imu[i].dev); } pm_runtime_disable(&pdev->dev); for (i = 0; i < data->plat_data->banks_num; i++) {