Messages in this thread | | | Date | Thu, 16 Dec 2021 14:15:14 +0100 | From | Greg KH <> | Subject | Re: [PATCH v2] serial: pch_uart: potential dereference of null pointer |
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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
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