Re: [PATCH v2] ALSA: ymfpci: Handle return NULL error from ioremap_nocache

[Takashi Iwai]

On Mon, 23 Jan 2017 08:36:28 +0100,
Arvind Yadav wrote:
> 
> Here, If ioremap_nocache will fail. It will return NULL.
> Kernel can run into a NULL-pointer dereference.
> This error check will avoid NULL pointer dereference.
> 
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
> ---
>  sound/pci/ymfpci/ymfpci_main.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/sound/pci/ymfpci/ymfpci_main.c b/sound/pci/ymfpci/ymfpci_main.c
> index ffee284..8590c3f 100644
> --- a/sound/pci/ymfpci/ymfpci_main.c
> +++ b/sound/pci/ymfpci/ymfpci_main.c
> @@ -2392,6 +2392,10 @@ int snd_ymfpci_create(struct snd_card *card,
>  	chip->rev = pci->revision;
>  	chip->reg_area_phys = pci_resource_start(pci, 0);
>  	chip->reg_area_virt = ioremap_nocache(chip->reg_area_phys, 0x8000);
> +	if (!chip->reg_area_virt) {
> +		pci_disable_device(pci);
> +		return -ENOMEM;

You forgot to release chip.  Otherwise it leads memory.


thanks,

Takashi