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 01D802EA143; Tue, 17 Jun 2025 16:01:36 +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=1750176097; cv=none; b=Zr/4GYBBIx4Mra4pZAsRo5g067e3btTtqE8rPbi00vUn6JUWhW+Oj2tcljVTKmQfK/AXMypuqL2T3vZTEAdKuQ5xLVjh6aT9SHFWxsIPWcwRmzcSdIzkEQmbLEpC6OWt0F1H1gcEzrPQbepIDAWwFk+jyEWjLIAOhxskmmQ4Xl8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750176097; c=relaxed/simple; bh=wk/E3CumYGsHHNMj7/znCPaeXCYn6xW+FqwEOoeKNNs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h9DtgKUk0pwK1S7Vl3jJ0OxcwDcM49tnK1EwKDFPN0CjQJa8pZCcYR7jsAsrBW5mWvQoErElUDCNrKEN8ZvhlcpOLsKrs4/NCJ2EwPU1Z1STfHVarlkmGr+0BOQYw0JFOGjGOmSYmNrIfAvXBoa1BFMdwGiyIYmB7GcxOTfg3EA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VPz22C90; 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="VPz22C90" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67F31C4CEE3; Tue, 17 Jun 2025 16:01:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750176096; bh=wk/E3CumYGsHHNMj7/znCPaeXCYn6xW+FqwEOoeKNNs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VPz22C901QQ31STPfDkITe2AsT2ewyTVWhneNz3KoKlJd6/rLXpCp+9bzwsB0BjpB EHZvuMm+5lzOL9G7+pZGxz4C8AWFe/4bXgzUrv1UNdx+39YBQxwUd+0msd/noTYh1n qPpZN1LyzRyJDsihQmSO+zAs0L0NRZTMU0C5Yo0c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chen-Yu Tsai , AngeloGioacchino Del Regno , Chun-Kuang Hu , Sasha Levin Subject: [PATCH 6.15 151/780] drm/mediatek: Fix kobject put for component sub-drivers Date: Tue, 17 Jun 2025 17:17:39 +0200 Message-ID: <20250617152457.652000822@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250617152451.485330293@linuxfoundation.org> References: <20250617152451.485330293@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: AngeloGioacchino Del Regno [ Upstream commit 80805b62ea5b95eda54c225b989f929ca0691ab0 ] In function mtk_drm_get_all_drm_priv(), this driver is incrementing the refcount for the sub-drivers of mediatek-drm with a call to device_find_child() when taking a reference to all of those child devices. When the component bind fails multiple times this results in a refcount_t overflow, as the reference count is never decremented: fix that by adding a call to put_device() for all of the mmsys devices in a loop, in error cases of mtk_drm_bind() and in the mtk_drm_unbind() callback. Fixes: 1ef7ed48356c ("drm/mediatek: Modify mediatek-drm for mt8195 multi mmsys support") Reviewed-by: Chen-Yu Tsai Signed-off-by: AngeloGioacchino Del Regno Link: https://patchwork.kernel.org/project/dri-devel/patch/20250403104741.71045-3-angelogioacchino.delregno@collabora.com/ Signed-off-by: Chun-Kuang Hu Signed-off-by: Sasha Levin --- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index 5994e2a97dc13..593193555c07e 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -682,6 +682,10 @@ static int mtk_drm_bind(struct device *dev) for (i = 0; i < private->data->mmsys_dev_num; i++) private->all_drm_private[i]->drm = NULL; err_put_dev: + for (i = 0; i < private->data->mmsys_dev_num; i++) { + /* For device_find_child in mtk_drm_get_all_priv() */ + put_device(private->all_drm_private[i]->dev); + } put_device(private->mutex_dev); return ret; } @@ -689,6 +693,7 @@ static int mtk_drm_bind(struct device *dev) static void mtk_drm_unbind(struct device *dev) { struct mtk_drm_private *private = dev_get_drvdata(dev); + int i; /* for multi mmsys dev, unregister drm dev in mmsys master */ if (private->drm_master) { @@ -696,6 +701,10 @@ static void mtk_drm_unbind(struct device *dev) mtk_drm_kms_deinit(private->drm); drm_dev_put(private->drm); + for (i = 0; i < private->data->mmsys_dev_num; i++) { + /* For device_find_child in mtk_drm_get_all_priv() */ + put_device(private->all_drm_private[i]->dev); + } put_device(private->mutex_dev); } private->mtk_drm_bound = false; -- 2.39.5