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 D2A05C77B73 for ; Mon, 1 May 2023 02:58:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232336AbjEAC6p (ORCPT ); Sun, 30 Apr 2023 22:58:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229663AbjEAC61 (ORCPT ); Sun, 30 Apr 2023 22:58:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5E7E10E5; Sun, 30 Apr 2023 19:57:54 -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 E336B60EA5; Mon, 1 May 2023 02:57:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63A63C4339B; Mon, 1 May 2023 02:57:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1682909873; bh=sOFCupPmco37yPY4TQcRSbwtpvyDHpYMv3Rmg9UkMo0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A8jEoIBbHxmeBxIweXizrk5AeWKWm9MyhYWDWsHfLeF9o0NjWm935jhxYbUy8m+21 g7geW7vSWiH5Qa1/fpYidyFAWgFkp2jVMJMIXtmSj6Uh+MymeVf1rwnkMekHNPTjrH BulYpLSbPrqRdDowrWrfxY/AzarZhhCzYuuX0P6Csgu3KaTPZpD6ixffbCZ+Mzo9pw oYzmH2H0S4e7HGxH2wnopNAuybf17o/x2MdErzEXr7GD1ye526m6Cw6qzILEbrx0Ke 5yAWn3f421nctW+KVhYANBId9zgTFWOjFzzAp+n/mQJfsJqSpyjJrXIl5ePNVjxujH emzmDrcs3vqIQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: harperchen , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin , hverkuil@xs4all.nl, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 6.3 15/44] media: pci: tw68: Fix null-ptr-deref bug in buf prepare and finish Date: Sun, 30 Apr 2023 22:56:03 -0400 Message-Id: <20230501025632.3253067-15-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230501025632.3253067-1-sashal@kernel.org> References: <20230501025632.3253067-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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