Re: [PATCH v2 iwl-next] ice: Fix some null pointer dereference issues in ice_ptp.c

[Przemek Kitszel]

On 12/12/23 03:40, Kunwu Chan wrote:
> devm_kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.
>
> Fixes: d938a8cca88a ("ice: Auxbus devices & driver for E822 TS")
> Cc: Kunwu Chan <kunwu.chan@xxxxxxxxxxx>
> Suggested-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>

You found the bug (or some some static analysis tool in that case);
there is no need to add Suggested-by for every person that suggests
something during review - the tag is for "person/s that suggested
making such change in the repo".

Subject line would be better if less generic, eg:
ice: avoid null deref of ptp auxbus name

> Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
> ---
>   drivers/net/ethernet/intel/ice/ice_ptp.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
> index e9e59f4b5580..848e3e063e64 100644
> --- a/drivers/net/ethernet/intel/ice/ice_ptp.c
> +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
> @@ -2743,6 +2743,8 @@ static int ice_ptp_register_auxbus_driver(struct ice_pf *pf)
>   	name = devm_kasprintf(dev, GFP_KERNEL, "ptp_aux_dev_%u_%u_clk%u",
>   			      pf->pdev->bus->number, PCI_SLOT(pf->pdev->devfn),
>   			      ice_get_ptp_src_clock_index(&pf->hw));
> +	if (!name)
> +		return -ENOMEM;
>   
>   	aux_driver->name = name;
>   	aux_driver->shutdown = ice_ptp_auxbus_shutdown;
> @@ -2989,6 +2991,8 @@ static int ice_ptp_create_auxbus_device(struct ice_pf *pf)
>   	name = devm_kasprintf(dev, GFP_KERNEL, "ptp_aux_dev_%u_%u_clk%u",
>   			      pf->pdev->bus->number, PCI_SLOT(pf->pdev->devfn),
>   			      ice_get_ptp_src_clock_index(&pf->hw));
> +	if (!name)
> +		return -ENOMEM;
>   
>   	aux_dev->name = name;
>   	aux_dev->id = id;

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>

Regarding iwl-next vs iwl-net: this bug is really unlikely to manifest,
as we take care of both earlier and future mem allocs for ptp auxbus,
and auxiliary_device_init() checks for null name, so no big deal,
so: -next is fine