Re: [PATCH -next] IB/srpt: Fix passing zero to 'PTR_ERR'

[Leon Romanovsky]

On Wed, Mar 24, 2021 at 10:09:39PM +0800, YueHaibing wrote:
> Fix smatch warning:
> 
> drivers/infiniband/ulp/srpt/ib_srpt.c:2341 srpt_cm_req_recv() warn: passing zero to 'PTR_ERR'
> 
> Use PTR_ERR_OR_ZERO instead of PTR_ERR
> 
> Fixes: 847462de3a0a ("IB/srpt: Fix srpt_cm_req_recv() error path (1/2)")
> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
> ---
>  drivers/infiniband/ulp/srpt/ib_srpt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
> index 6be60aa5ffe2..3ff24b5048ac 100644
> --- a/drivers/infiniband/ulp/srpt/ib_srpt.c
> +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
> @@ -2338,7 +2338,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,
>  
>  	if (IS_ERR_OR_NULL(ch->sess)) {
>  		WARN_ON_ONCE(ch->sess == NULL);
> -		ret = PTR_ERR(ch->sess);
> +		ret = PTR_ERR_OR_ZERO(ch->sess);

It is crazy, in first line, we checked ch->sess and allowed it to be NULL,
later caused to kernel panic and set ret to success.

>  		ch->sess = NULL;
>  		pr_info("Rejected login for initiator %s: ret = %d.\n",
>  			ch->sess_name, ret);
> -- 
> 2.22.0
>