Re: [PATCH] PCI: fix possible null-pointer dereference about devname

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc Christoph, 704e8953d3e9 author]

On Mon, Nov 21, 2022 at 10:00:29AM +0800, Zeng Heng wrote:
> When kvasprintf() fails to allocate memory, it would return
> null-pointer. In case of null pointer dereferencing, fix it
> by returning error number directly from the function.
> 
> Fixes: 704e8953d3e9 ("PCI/irq: Add pci_request_irq() and pci_free_irq() helpers")
> Signed-off-by: Zeng Heng <zengheng4@huawei.com>
> ---
>  drivers/pci/irq.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c
> index 12ecd0aaa28d..0050e8f6814e 100644
> --- a/drivers/pci/irq.c
> +++ b/drivers/pci/irq.c
> @@ -44,6 +44,8 @@ int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler,
>  	va_start(ap, fmt);
>  	devname = kvasprintf(GFP_KERNEL, fmt, ap);
>  	va_end(ap);
> +	if (!devname)
> +		return -ENOMEM;
>  
>  	ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
>  				   irqflags, devname, dev_id);
> -- 
> 2.25.1
>