From: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
commit e8914b52e5b024e4af3d810a935fe0805eee8a36 upstream.
A local variable sg is used to store scatterlist pointer in
pch_dma_tx_complete(). The for loop doing Tx byte accounting before
dma_unmap_sg() alters sg in its increment statement. Therefore, the
pointer passed into dma_unmap_sg() won't match to the one given to
dma_map_sg().
To fix the problem, use priv->sg_tx_p directly in dma_unmap_sg()
instead of the local variable.
Fixes: da3564ee027e ("pch_uart: add multi-scatter processing")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230103093435.4396-1-ilpo.jarvinen@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/pch_uart.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -776,7 +776,7 @@ static void pch_dma_tx_complete(void *ar
}
xmit->tail &= UART_XMIT_SIZE - 1;
async_tx_ack(priv->desc_tx);
- dma_unmap_sg(port->dev, sg, priv->orig_nent, DMA_TO_DEVICE);
+ dma_unmap_sg(port->dev, priv->sg_tx_p, priv->orig_nent, DMA_TO_DEVICE);
priv->tx_dma_use = 0;
priv->nent = 0;
priv->orig_nent = 0;
