From: Greg KH <gregkh@linuxfoundation.org>
To: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc: jirislaby@kernel.org, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] serial: pch_uart: potential dereference of null pointer
Date: Thu, 16 Dec 2021 14:15:14 +0100 [thread overview]
Message-ID: <Ybs74r4fjDudyJ4C@kroah.com> (raw)
In-Reply-To: <20211216125121.399938-1-jiasheng@iscas.ac.cn>
On Thu, Dec 16, 2021 at 08:51:21PM +0800, Jiasheng Jiang wrote:
> The return value of dma_alloc_coherent() needs to be checked.
> To avoid dereference of null pointer in case of the failure of alloc.
>
> Fixes: ab4382d27412 ("tty: move drivers/serial/ to drivers/tty/serial/")
That is not the commit that caused the problem :(
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
> Changelog:
>
> v1 -> v2
>
> *Change 1. Add the dev_err when dma_alloc_coherent failed.
> ---
> drivers/tty/serial/pch_uart.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
> index f0351e6f0ef6..d19ed7da24fa 100644
> --- a/drivers/tty/serial/pch_uart.c
> +++ b/drivers/tty/serial/pch_uart.c
> @@ -745,6 +745,14 @@ static void pch_request_dma(struct uart_port *port)
> /* Get Consistent memory for DMA */
> priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize,
> &priv->rx_buf_dma, GFP_KERNEL);
> + if (!priv->rx_buf_virt) {
> + dev_err(priv->port.dev, "%s:dma_alloc_coherent FAILS(Rx)\n",
> + __func__);
> + dma_release_channel(priv->chan_tx);
> + priv->chan_tx = NULL;
> + return;
You seemed to have ignored my previous review comments on this change
for some reason :(
This is not correct.
greg k-h
prev parent reply other threads:[~2021-12-16 13:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-16 12:51 [PATCH v2] serial: pch_uart: potential dereference of null pointer Jiasheng Jiang
2021-12-16 13:15 ` Greg KH [this message]
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