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 E25BD2C21CB; Mon, 20 Oct 2025 04:56:37 +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=1760936198; cv=none; b=kPcmAzGcA5WRvVNAUNo6bje0zyWr7P2BFNM4zeox5HRV4k5oO9zKs+rNK5eQBzSJlWqtcN/3TvjqmFblRBlhrjdGQZDCLorM6kA+5n+ZV1RDIxe3oAuRVxGT0VZKMlJmoniAwqqfkzHl+BGBRX5PhWtDLmOw5n5RUVLONvvyhhY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760936198; c=relaxed/simple; bh=Uphrj0V5NRAywmcIq5nn1A5c0/bedTfijWA5afzFZQQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CL3ODAncQUQvcNiskGFBqcBUIkwdheQNcFc9CAUSBrDZYnoDkIUE09VOtI3WHPT1kgstuftR8hPpNhjEzaLIj4wltm/HWOPvKW5mr6xdYDr4p4iNPp342a/Ma907oItb1n+WsGq7YFSvOHG/i9Nsi2W3tQZ9F7JsFJOut09iMRQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AgyEXD31; 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="AgyEXD31" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F83AC4CEF9; Mon, 20 Oct 2025 04:56:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760936197; bh=Uphrj0V5NRAywmcIq5nn1A5c0/bedTfijWA5afzFZQQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AgyEXD314z4HElDhu3YoDBwzu1iw1JHxcAKLKio+3ERYoaB1Ytuqj9GzdQPbnR2b0 F9DqV2Cm0YTMCkpf4m9Tc9fPsvJos1ZFL+3bJnms9S5HNnDS6bxfogaD+AUXefiSm+ OEZcpEHs6awyC1rR8gO8nv3lBeNl+vFovfJwDV/Lgen+WQQ/icrdGenmgvPtm28N8A z28Zok+VprM1o4+eEunK5kw71JGERnWdc+tOnO+i0+HuugikCOyXRinvMkpqUYbrgJ qHXxsR1HytNykp38kH4KltHZt/UUKLOeaF7PrspdcCj63tgv8pNnF3/K6Wt1dv4z/n 2eZ675hcJ4yfg== Received: from johan by xi.lan with local (Exim 4.98.2) (envelope-from ) id 1vAhwn-0000000083E-1NA6; Mon, 20 Oct 2025 06:56:41 +0200 From: Johan Hovold To: Joerg Roedel , Will Deacon Cc: Robin Murphy , Sven Peter , Janne Grunau , Rob Clark , Marek Szyprowski , Yong Wu , Matthias Brugger , AngeloGioacchino Del Regno , Chen-Yu Tsai , Thierry Reding , Krishna Reddy , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH v3 06/14] iommu/mediatek: fix use-after-free on probe deferral Date: Mon, 20 Oct 2025 06:53:10 +0200 Message-ID: <20251020045318.30690-7-johan@kernel.org> X-Mailer: git-send-email 2.49.1 In-Reply-To: <20251020045318.30690-1-johan@kernel.org> References: <20251020045318.30690-1-johan@kernel.org> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 --- drivers/iommu/mtk_iommu.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 8d8e85186188..64ce041238fd 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -1213,16 +1213,19 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m } 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, @@ -1230,7 +1233,8 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m 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; @@ -1402,8 +1406,12 @@ static int mtk_iommu_probe(struct platform_device *pdev) 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; @@ -1423,6 +1431,9 @@ static void mtk_iommu_remove(struct platform_device *pdev) 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++) { -- 2.49.1