spi: spi-topcliff-pch: Fix potential double free in pch_spi_process_messages()

pch_spi_set_tx() frees data->pkt_tx_buff on failure of kzalloc() for
data->pkt_rx_buff, but its caller, pch_spi_process_messages(), will
free data->pkt_tx_buff again. Set data->pkt_tx_buff to NULL after
kfree() to avoid double free.

Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620284888-65215-1-git-send-email-f.fangjian@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index b887078..8c4615b 100644 (file)
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -580,8 +580,10 @@ static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw)
        data->pkt_tx_buff = kzalloc(size, GFP_KERNEL);
        if (data->pkt_tx_buff != NULL) {
                data->pkt_rx_buff = kzalloc(size, GFP_KERNEL);
-               if (!data->pkt_rx_buff)
+               if (!data->pkt_rx_buff) {
                        kfree(data->pkt_tx_buff);
+                       data->pkt_tx_buff = NULL;
+               }
        }
 
        if (!data->pkt_rx_buff) {