[PATCH] Add checks for kmalloc allocation failures

From: Colin King
Date: Wed Mar 29 2017 - 11:55:03 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Ensure we don't end up with a null pointer dereferences by checking
for for allocation failures. Allocate by sizeof(*ptr) rather than
the type to fix checkpack warnings. Also merge multiple lines into
one line for the kmalloc call.

Detected by CoverityScan, CID#1422435 ("Dereference null return value")

Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/net/ieee802154/ca8210.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c
index 53fa87bfede0..25fd3b04b3c0 100644
--- a/drivers/net/ieee802154/ca8210.c
+++ b/drivers/net/ieee802154/ca8210.c
@@ -634,6 +634,8 @@ static int ca8210_test_int_driver_write(
dev_dbg(&priv->spi->dev, "%#03x\n", buf[i]);

fifo_buffer = kmalloc(len, GFP_KERNEL);
+ if (!fifo_buffer)
+ return -ENOMEM;
memcpy(fifo_buffer, buf, len);
kfifo_in(&test->up_fifo, &fifo_buffer, 4);
wake_up_interruptible(&priv->test.readq);
@@ -759,10 +761,10 @@ static void ca8210_rx_done(struct cas_control *cas_ctl)
&priv->spi->dev,
"Resetting MAC...\n");

- mlme_reset_wpc = kmalloc(
- sizeof(struct work_priv_container),
- GFP_KERNEL
- );
+ mlme_reset_wpc = kmalloc(sizeof(*mlme_reset_wpc),
+ GFP_KERNEL);
+ if (!mlme_reset_wpc)
+ goto finish;
INIT_WORK(
&mlme_reset_wpc->work,
ca8210_mlme_reset_worker
@@ -925,10 +927,10 @@ static int ca8210_spi_transfer(

dev_dbg(&spi->dev, "ca8210_spi_transfer called\n");

- cas_ctl = kmalloc(
- sizeof(struct cas_control),
- GFP_ATOMIC
- );
+ cas_ctl = kmalloc(sizeof(*cas_ctl), GFP_ATOMIC);
+ if (!cas_ctl)
+ return -ENOMEM;
+
cas_ctl->priv = priv;
memset(cas_ctl->tx_buf, SPI_IDLE, CA8210_SPI_BUF_SIZE);
memset(cas_ctl->tx_in_buf, SPI_IDLE, CA8210_SPI_BUF_SIZE);
--
2.11.0