[PATCH] spi: spi-topcliff-pch: Fixed the possible null pointer exception issue

From: lijian_8010a29
Date: Thu Jun 24 2021 - 06:52:05 EST


From: lijian <lijian@xxxxxxxxxx>

The 'data->pkt_tx_buff' is used after called
‘kfree(data->pkt_tx_buff)’,it may be null when it is called,
and null pointer exception may occur,
so judgment is added when using 'data->pkt_tx_buff'.

Signed-off-by: lijian <lijian@xxxxxxxxxx>
---
drivers/spi/spi-topcliff-pch.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index b8870784fc6e..a5ac59f2eb80 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -599,7 +599,7 @@ static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw)
}

/* copy Tx Data */
- if (data->cur_trans->tx_buf != NULL) {
+ if ((data->cur_trans->tx_buf != NULL) && (data->pkt_tx_buff != NULL)) {
if (*bpw == 8) {
tx_buf = data->cur_trans->tx_buf;
for (j = 0; j < data->bpw_len; j++)
@@ -621,8 +621,10 @@ static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw)
__func__);
pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);

- for (j = 0; j < n_writes; j++)
- pch_spi_writereg(data->master, PCH_SPDWR, data->pkt_tx_buff[j]);
+ if (data->pkt_tx_buff != NULL) {
+ for (j = 0; j < n_writes; j++)
+ pch_spi_writereg(data->master, PCH_SPDWR, data->pkt_tx_buff[j]);
+ }

/* update tx_index */
data->tx_index = j;
--
2.25.1