Re: [PATCH] PCI: iproc: fix kernel crash if dev->of_node not defined

[Bjorn Helgaas]

On Fri, Jan 13, 2017 at 03:20:17AM +0300, Abylay Ospan wrote:
> pcie->dev->of_node not always defined (NULL) and can cause crash:
> 
> [   19.053195] Unable to handle kernel NULL pointer dereference at
> virtual address 00000020
> [<c0b0370c>] (of_n_addr_cells) from [<c06599c4>]
> (iproc_pcie_setup+0x30c/0xce0)
> 
> this patch adds sanity check to prevent crash.
> 
> Signed-off-by: Abylay Ospan <aospan@xxxxxxxx>

Hi Abylay, this didn't look quite fully baked yet, so I'm dropping it for
now.  Please repost if everything's been worked out and the patch is still
necessary.

> ---
>  drivers/pci/host/pcie-iproc.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
> index 3ebc025..f2836a9 100644
> --- a/drivers/pci/host/pcie-iproc.c
> +++ b/drivers/pci/host/pcie-iproc.c
> @@ -952,6 +952,9 @@ static int pci_dma_range_parser_init(struct of_pci_range_parser *parser,
>  	const int na = 3, ns = 2;
>  	int rlen;
>  
> +	if (!node)
> +		return -ENOENT;
> +
>  	parser->node = node;
>  	parser->pna = of_n_addr_cells(node);
>  	parser->np = parser->pna + na + ns;
> -- 
> 2.7.4
> 
> 
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