Re: [PATCH] Add checks for kmalloc allocation failures

From: walter harms
Date: Wed Mar 29 2017 - 14:55:28 EST




Am 29.03.2017 17:54, schrieb Colin King:
> 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);


perhaps kmemdup() ist the way to go ?
by replace kamlloc()+memcpy

re,
wh

> 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);