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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3147AC7EE2E for ; Mon, 22 May 2023 19:39:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235021AbjEVTjf (ORCPT ); Mon, 22 May 2023 15:39:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235041AbjEVTjd (ORCPT ); Mon, 22 May 2023 15:39:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01CA5CA for ; Mon, 22 May 2023 12:39:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D6BD3629DD for ; Mon, 22 May 2023 19:39:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E29F0C433EF; Mon, 22 May 2023 19:39:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684784370; bh=sOFCupPmco37yPY4TQcRSbwtpvyDHpYMv3Rmg9UkMo0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zsVD1Bu5MImeYANGK3ujS3C+t2MsZsHj4zKBg1E+q/+pzJrZbTsubwqTgF7K7DO+O l6tqn+MWRUIx5xJbh5BnoJYFkRDvfkk2neqFOVJX5K3cuX+ndQ7jFv2vJLKi6sYmHm FzTDsVoANXVgDRJLvyebKKQop6i0bbANEb/xQXpc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, harperchen , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 6.3 059/364] media: pci: tw68: Fix null-ptr-deref bug in buf prepare and finish Date: Mon, 22 May 2023 20:06:04 +0100 Message-Id: <20230522190414.267484074@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230522190412.801391872@linuxfoundation.org> References: <20230522190412.801391872@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: harperchen [ Upstream commit 1634b7adcc5bef645b3666fdd564e5952a9e24e0 ] When the driver calls tw68_risc_buffer() to prepare the buffer, the function call dma_alloc_coherent may fail, resulting in a empty buffer buf->cpu. Later when we free the buffer or access the buffer, null ptr deref is triggered. This bug is similar to the following one: https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71. We believe the bug can be also dynamically triggered from user side. Similarly, we fix this by checking the return value of tw68_risc_buffer() and the value of buf->cpu before buffer free. Signed-off-by: harperchen Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/pci/tw68/tw68-video.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/media/pci/tw68/tw68-video.c b/drivers/media/pci/tw68/tw68-video.c index 0cbc5b038073b..773a18702d369 100644 --- a/drivers/media/pci/tw68/tw68-video.c +++ b/drivers/media/pci/tw68/tw68-video.c @@ -437,6 +437,7 @@ static void tw68_buf_queue(struct vb2_buffer *vb) */ static int tw68_buf_prepare(struct vb2_buffer *vb) { + int ret; struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); struct vb2_queue *vq = vb->vb2_queue; struct tw68_dev *dev = vb2_get_drv_priv(vq); @@ -452,30 +453,30 @@ static int tw68_buf_prepare(struct vb2_buffer *vb) bpl = (dev->width * dev->fmt->depth) >> 3; switch (dev->field) { case V4L2_FIELD_TOP: - tw68_risc_buffer(dev->pci, buf, dma->sgl, + ret = tw68_risc_buffer(dev->pci, buf, dma->sgl, 0, UNSET, bpl, 0, dev->height); break; case V4L2_FIELD_BOTTOM: - tw68_risc_buffer(dev->pci, buf, dma->sgl, + ret = tw68_risc_buffer(dev->pci, buf, dma->sgl, UNSET, 0, bpl, 0, dev->height); break; case V4L2_FIELD_SEQ_TB: - tw68_risc_buffer(dev->pci, buf, dma->sgl, + ret = tw68_risc_buffer(dev->pci, buf, dma->sgl, 0, bpl * (dev->height >> 1), bpl, 0, dev->height >> 1); break; case V4L2_FIELD_SEQ_BT: - tw68_risc_buffer(dev->pci, buf, dma->sgl, + ret = tw68_risc_buffer(dev->pci, buf, dma->sgl, bpl * (dev->height >> 1), 0, bpl, 0, dev->height >> 1); break; case V4L2_FIELD_INTERLACED: default: - tw68_risc_buffer(dev->pci, buf, dma->sgl, + ret = tw68_risc_buffer(dev->pci, buf, dma->sgl, 0, bpl, bpl, bpl, dev->height >> 1); break; } - return 0; + return ret; } static void tw68_buf_finish(struct vb2_buffer *vb) @@ -485,7 +486,8 @@ static void tw68_buf_finish(struct vb2_buffer *vb) struct tw68_dev *dev = vb2_get_drv_priv(vq); struct tw68_buf *buf = container_of(vbuf, struct tw68_buf, vb); - dma_free_coherent(&dev->pci->dev, buf->size, buf->cpu, buf->dma); + if (buf->cpu) + dma_free_coherent(&dev->pci->dev, buf->size, buf->cpu, buf->dma); } static int tw68_start_streaming(struct vb2_queue *q, unsigned int count) -- 2.39.2