Re: [PATCH] IB/hfi1: Prevent a NULL dereference

[Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>]

On 1/9/2018 4:27 AM, Dan Carpenter wrote:
> In the original code, we set "fd->uctxt" to NULL and then dereference it
> which will cause an Oops.
>
> Fixes: f2a3bc00a03c ("IB/hfi1: Protect context array set/clear with spinlock")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
> index 82086241aac3..3de1ac94bb85 100644
> --- a/drivers/infiniband/hw/hfi1/file_ops.c
> +++ b/drivers/infiniband/hw/hfi1/file_ops.c
> @@ -763,10 +763,10 @@ static int complete_subctxt(struct hfi1_filedata *fd)
>   	}
>   
>   	if (ret) {
> +		__clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
>   		hfi1_rcd_put(fd->uctxt);
>   		fd->uctxt = NULL;
>   		spin_lock_irqsave(&fd->dd->uctxt_lock, flags);
> -		__clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
>   		spin_unlock_irqrestore(&fd->dd->uctxt_lock, flags);
>   	}
>   

Thanks!

Acked-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html