[PATCH 4.4 027/188] spi: spi-topcliff-pch: Fix potential double free in pch_spi_process_messages()

Greg Kroah-Hartman
2021-07-19T14:57:23Z

From: Jay Fang <f.fangjian@huawei.com>

[ Upstream commit 026a1dc1af52742c5897e64a3431445371a71871 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-topcliff-pch.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 9f30a4ab2004..66c170e799fc 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -589,8 +589,10 @@ 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) {
--
2.30.2