Re: [PATCH 1/1] iw_cxgb4: check return value of alloc_skb

[Leon Romanovsky <leon@kernel.org>]

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On Sun, Apr 23, 2017 at 05:09:11PM +0800, Pan Bian wrote:
> Function alloc_skb() will return a NULL pointer when there is no enough
> memory. However, the return value of alloc_skb() is directly used
> without validation in function send_fw_pass_open_req(). This patches
> checks the return value of alloc_skb() against NULL.
>
> Signed-off-by: Pan Bian <bianpan2016@163.com>
> ---
>  drivers/infiniband/hw/cxgb4/cm.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
> index 03a1b0e..196969c 100644
> --- a/drivers/infiniband/hw/cxgb4/cm.c
> +++ b/drivers/infiniband/hw/cxgb4/cm.c
> @@ -3800,6 +3800,8 @@ static void send_fw_pass_open_req(struct c4iw_dev *dev, struct sk_buff *skb,
>  	int ret;
>
>  	req_skb = alloc_skb(sizeof(struct fw_ofld_connection_wr), GFP_KERNEL);
> +	if (!req_skb)
> +		return;

The check is right, but the outcome is unpredictable. The function
send_fw_pass_open_req() doesn't return any error and caller doesn't check
it.

>  	req = (struct fw_ofld_connection_wr *)__skb_put(req_skb, sizeof(*req));
>  	memset(req, 0, sizeof(*req));
>  	req->op_compl = htonl(WR_OP_V(FW_OFLD_CONNECTION_WR) | FW_WR_COMPL_F);
> --
> 1.9.1
>
>

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