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 A84BBC77B60 for ; Mon, 1 May 2023 02:59:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232318AbjEAC72 (ORCPT ); Sun, 30 Apr 2023 22:59:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49464 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232267AbjEAC6s (ORCPT ); Sun, 30 Apr 2023 22:58:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE4561715; Sun, 30 Apr 2023 19:58:21 -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 797A360ED1; Mon, 1 May 2023 02:57:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A289C433D2; Mon, 1 May 2023 02:57:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1682909869; bh=F3Wiov1pCS4WKo5KfIAZ+ApsN7GR7v4FG6BtkmgA1Zk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZpMPyCq09vDkYfYG4DI1nHZIRK2sN7BJaBili1iiu0ZVNoKN7+rLM3TDhW0jCAsFQ haQotsXVQYpaoKZCxfCUK0TzY9i2+2WG5N/ShXvGkisHG2WzhuwuphcGANLglPHcKe NcuSF2Lu4nkpoRwaOklntpzGItEVTgI7CDex1covyKhFMTNUe2dD5HCX+mQYcZDhmJ 37c/ncmYrPD8Y4eZ1/J/HZXee3TFyzpYw8Lysseytk4RFYZ5AcZ1QUx/OmPerOdfRg RH5/NQjgoRrOtzNW8beuOG/LrFWbpGOwmPmghsqP0zDz21dVUvsUZzoHE5/eikumaF UHLzuW7qxjKaA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: harperchen , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin , daniel.lee.kruse@proton.me, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 6.3 14/44] media: cx23885: Fix a null-ptr-deref bug in buffer_prepare() and buffer_finish() Date: Sun, 30 Apr 2023 22:56:02 -0400 Message-Id: <20230501025632.3253067-14-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 47e8b73bc35d7c54642f78e498697692f6358996 ] When the driver calls cx23885_risc_buffer() to prepare the buffer, the function call dma_alloc_coherent may fail, resulting in a empty buffer risc->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 cx23885_risc_buffer() and the value of risc->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/cx23885/cx23885-core.c | 4 +++- drivers/media/pci/cx23885/cx23885-video.c | 13 +++++++------ 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/drivers/media/pci/cx23885/cx23885-core.c b/drivers/media/pci/cx23885/cx23885-core.c index 9232a966bcabb..2ce2914576cf2 100644 --- a/drivers/media/pci/cx23885/cx23885-core.c +++ b/drivers/media/pci/cx23885/cx23885-core.c @@ -1325,7 +1325,9 @@ void cx23885_free_buffer(struct cx23885_dev *dev, struct cx23885_buffer *buf) { struct cx23885_riscmem *risc = &buf->risc; - dma_free_coherent(&dev->pci->dev, risc->size, risc->cpu, risc->dma); + if (risc->cpu) + dma_free_coherent(&dev->pci->dev, risc->size, risc->cpu, risc->dma); + memset(risc, 0, sizeof(*risc)); } static void cx23885_tsport_reg_dump(struct cx23885_tsport *port) diff --git a/drivers/media/pci/cx23885/cx23885-video.c b/drivers/media/pci/cx23885/cx23885-video.c index 3d03f5e95786a..671fc0588e431 100644 --- a/drivers/media/pci/cx23885/cx23885-video.c +++ b/drivers/media/pci/cx23885/cx23885-video.c @@ -342,6 +342,7 @@ static int queue_setup(struct vb2_queue *q, static int buffer_prepare(struct vb2_buffer *vb) { + int ret; struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); struct cx23885_dev *dev = vb->vb2_queue->drv_priv; struct cx23885_buffer *buf = @@ -358,12 +359,12 @@ static int buffer_prepare(struct vb2_buffer *vb) switch (dev->field) { case V4L2_FIELD_TOP: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, 0, UNSET, buf->bpl, 0, dev->height); break; case V4L2_FIELD_BOTTOM: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, UNSET, 0, buf->bpl, 0, dev->height); break; @@ -391,21 +392,21 @@ static int buffer_prepare(struct vb2_buffer *vb) line0_offset = 0; line1_offset = buf->bpl; } - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, line0_offset, line1_offset, buf->bpl, buf->bpl, dev->height >> 1); break; case V4L2_FIELD_SEQ_TB: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, 0, buf->bpl * (dev->height >> 1), buf->bpl, 0, dev->height >> 1); break; case V4L2_FIELD_SEQ_BT: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, buf->bpl * (dev->height >> 1), 0, buf->bpl, 0, @@ -418,7 +419,7 @@ static int buffer_prepare(struct vb2_buffer *vb) buf, buf->vb.vb2_buf.index, dev->width, dev->height, dev->fmt->depth, dev->fmt->fourcc, (unsigned long)buf->risc.dma); - return 0; + return ret; } static void buffer_finish(struct vb2_buffer *vb) -- 2.39.2