Re: [PATCH 5/5] staging/lustre/lnet: fix potential null pointer dereference

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sun, Apr 27, 2014 at 05:17:26PM -0400, Oleg Drokin wrote:
> From: Dmitry Eremin <dmitry.eremin@intel.com>
> 
> Pointer 'ni' checked for NULL at line 1569 may be passed to
> function and may be dereferenced there by passing argument 1 to
> function 'lnet_ni_notify_locked' at line 1621.
> found by Klocwork Insight tool
> 
> Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
> Reviewed-on: http://review.whamcloud.com/9386
> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4629
> Reviewed-by: John L. Hammond <john.hammond@intel.com>
> Reviewed-by: Isaac Huang <he.huang@intel.com>
> Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
> ---
>  drivers/staging/lustre/lnet/lnet/router.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/lustre/lnet/lnet/router.c b/drivers/staging/lustre/lnet/lnet/router.c
> index 995f509..ba0278e 100644
> --- a/drivers/staging/lustre/lnet/lnet/router.c
> +++ b/drivers/staging/lustre/lnet/lnet/router.c
> @@ -1559,7 +1559,8 @@ lnet_notify(lnet_ni_t *ni, lnet_nid_t nid, int alive, cfs_time_t when)
>  
>  	lnet_notify_locked(lp, ni == NULL, alive, when);
>  
> -	lnet_ni_notify_locked(ni, lp);
> +	if (ni != NULL)
> +		lnet_ni_notify_locked(ni, lp);

Why can't lnet_ni_notify_locked() accept NULL as an input?