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

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

[Jay Fang]

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>
---
 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 b887078..8c4615b 100644
--- 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) {
-- 
2.7.4

Re: [PATCH] spi: spi-topcliff-pch: Fix potential double free in pch_spi_process_messages()

[Mark Brown]

On Thu, 6 May 2021 15:08:08 +0800, Jay Fang wrote:
> 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.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: spi-topcliff-pch: Fix potential double free in pch_spi_process_messages()
      commit: 026a1dc1af52742c5897e64a3431445371a71871

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark