From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A289AC433DF for ; Wed, 20 May 2020 13:16:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66003207D4 for ; Wed, 20 May 2020 13:16:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="Rsc7egtC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726833AbgETNQY (ORCPT ); Wed, 20 May 2020 09:16:24 -0400 Received: from lelv0142.ext.ti.com ([198.47.23.249]:51004 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726436AbgETNQY (ORCPT ); Wed, 20 May 2020 09:16:24 -0400 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 04KDGIPK075879; Wed, 20 May 2020 08:16:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1589980578; bh=g5mxtIyMDGJIfjMohatgyirw9qrdm5M7LriXPEsGKOs=; h=From:To:CC:Subject:Date; b=Rsc7egtCVTnZ9rJ3AC75KqbJbnXiFZortrfw8p98+O/9/rJfiEL+gPjjKKLLZiXwF JO8Ts9qbYTbLxlZOUdipIsJNH2Lrk+M+sBd53BrZSFD1519giTdG+BIuS3+ATSMbp8 LGkFjXBPKgKFpnJZh3FxGILUcx2pa1/hI6WdlMyE= Received: from DLEE102.ent.ti.com (dlee102.ent.ti.com [157.170.170.32]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id 04KDGIOC094815; Wed, 20 May 2020 08:16:18 -0500 Received: from DLEE111.ent.ti.com (157.170.170.22) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Wed, 20 May 2020 08:16:17 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DLEE111.ent.ti.com (157.170.170.22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Wed, 20 May 2020 08:16:17 -0500 Received: from deskari.lan (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 04KDGGnl086139; Wed, 20 May 2020 08:16:16 -0500 From: Tomi Valkeinen To: Linux Media Mailing List , Mauro Carvalho Chehab , Marek Szyprowski , Ulf Hansson CC: LKML , Tomi Valkeinen Subject: [PATCH] media: videobuf2-dma-contig: fix bad kfree in vb2_dma_contig_clear_max_seg_size Date: Wed, 20 May 2020 16:15:58 +0300 Message-ID: <20200520131558.23009-1-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 9495b7e92f716ab2bd6814fab5e97ab4a39adfdd ("driver core: platform: Initialize dma_parms for platform devices") in v5.7-rc5 causes vb2_dma_contig_clear_max_seg_size() to kfree memory that was not allocated by vb2_dma_contig_set_max_seg_size(). The assumption in vb2_dma_contig_set_max_seg_size() seems to be that dev->dma_parms is always NULL when the driver is probed, and the case where dev->dma_parms has bee initialized by someone else than the driver (by calling vb2_dma_contig_set_max_seg_size) will cause a failure. All the current users of these functions are platform devices, which now always have dma_parms set by the driver core. To fix the issue for v5.7, make vb2_dma_contig_set_max_seg_size() return an error if dma_parms is NULL to be on the safe side, and remove the kfree code from vb2_dma_contig_clear_max_seg_size(). For v5.8 we should remove the two functions and move the dma_set_max_seg_size() calls into the drivers. Signed-off-by: Tomi Valkeinen --- Note: I have only fully tested this on linux-next, as the capture driver I use doesn't support unloading modules in v5.7. drivers/media/common/videobuf2/videobuf2-dma-contig.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index d3a3ee5b597b..24f80b62ef94 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -726,9 +726,8 @@ EXPORT_SYMBOL_GPL(vb2_dma_contig_memops); int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size) { if (!dev->dma_parms) { - dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL); - if (!dev->dma_parms) - return -ENOMEM; + dev_err(dev, "Failed to set max_seg_size: dma_parms is NULL\n"); + return -ENODEV; } if (dma_get_max_seg_size(dev) < size) return dma_set_max_seg_size(dev, size); @@ -747,8 +746,6 @@ EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size); */ void vb2_dma_contig_clear_max_seg_size(struct device *dev) { - kfree(dev->dma_parms); - dev->dma_parms = NULL; } EXPORT_SYMBOL_GPL(vb2_dma_contig_clear_max_seg_size); -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. 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