RE: [PATCH][next] soc: fsl: dpio: fix dereference of pointer p before null check

[Leo Li]

> -----Original Message-----
> From: Colin King <colin.king@xxxxxxxxxxxxx>
> Sent: Friday, February 21, 2020 5:12 PM
> To: Roy Pledge <roy.pledge@xxxxxxx>; Leo Li <leoyang.li@xxxxxxx>; Youri
> Querry <youri.querry_1@xxxxxxx>; linuxppc-dev@xxxxxxxxxxxxxxxx; linux-
> arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: kernel-janitors@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH][next] soc: fsl: dpio: fix dereference of pointer p before null
> check
> 
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> Pointer p is currently being dereferenced before it is null checked on a
> memory allocation failure check. Fix this by checking if p is null before
> dereferencing it.
> 
> Addresses-Coverity: ("Dereference before null check")
> Fixes: 3b2abda7d28c ("soc: fsl: dpio: Replace QMAN array mode with ring
> mode enqueue")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Applied for next.  Thanks.

> ---
>  drivers/soc/fsl/dpio/qbman-portal.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/soc/fsl/dpio/qbman-portal.c
> b/drivers/soc/fsl/dpio/qbman-portal.c
> index 740ee0d19582..d1f49caa5b13 100644
> --- a/drivers/soc/fsl/dpio/qbman-portal.c
> +++ b/drivers/soc/fsl/dpio/qbman-portal.c
> @@ -249,10 +249,11 @@ struct qbman_swp *qbman_swp_init(const struct
> qbman_swp_desc *d)
>  	u32 mask_size;
>  	u32 eqcr_pi;
> 
> -	spin_lock_init(&p->access_spinlock);
> -
>  	if (!p)
>  		return NULL;
> +
> +	spin_lock_init(&p->access_spinlock);
> +
>  	p->desc = d;
>  	p->mc.valid_bit = QB_VALID_BIT;
>  	p->sdq = 0;
> --
> 2.25.0