This is a note to let you know that I've just added the patch titled
serial: pch: Fix PCI device refcount leak in pch_request_dma()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-pch-fix-pci-device-refcount-leak-in-pch_reque.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1e21d3061d7385e637b41faff619af3b23416ac7
Author: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
Date: Tue Nov 22 19:45:59 2022 +0800
serial: pch: Fix PCI device refcount leak in pch_request_dma()
[ Upstream commit 8be3a7bf773700534a6e8f87f6ed2ed111254be5 ]
As comment of pci_get_slot() says, it returns a pci_device with its
refcount increased. The caller must decrement the reference count by
calling pci_dev_put().
Since 'dma_dev' is only used to filter the channel in filter(), we can
call pci_dev_put() before exiting from pch_request_dma(). Add the
missing pci_dev_put() for the normal and error path.
Fixes: 3c6a483275f4 ("Serial: EG20T: add PCH_UART driver")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221122114559.27692-1-wangxiongfeng2@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index e5ff30544bd0..447990006d68 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -734,6 +734,7 @@ static void pch_request_dma(struct uart_port *port)
if (!chan) {
dev_err(priv->port.dev, "%s:dma_request_channel FAILS(Tx)\n",
__func__);
+ pci_dev_put(dma_dev);
return;
}
priv->chan_tx = chan;
@@ -750,6 +751,7 @@ static void pch_request_dma(struct uart_port *port)
__func__);
dma_release_channel(priv->chan_tx);
priv->chan_tx = NULL;
+ pci_dev_put(dma_dev);
return;
}
@@ -757,6 +759,8 @@ static void pch_request_dma(struct uart_port *port)
priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize,
&priv->rx_buf_dma, GFP_KERNEL);
priv->chan_rx = chan;
+
+ pci_dev_put(dma_dev);
}
static void pch_dma_rx_complete(void *arg)
