netdev - Re: [PATCH] sfc: Check null pointer of rx_queue->page

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <YcCQPA/EnHxYikYj@kroah.com>
Date:   Mon, 20 Dec 2021 15:16:28 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Jiasheng Jiang <jiasheng@...as.ac.cn>
Cc:     ecree.xilinx@...il.com, habetsm.xilinx@...il.com,
        davem@...emloft.net, kuba@...nel.org, ast@...nel.org,
        daniel@...earbox.net, hawk@...nel.org, john.fastabend@...il.com,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        bpf@...r.kernel.org
Subject: Re: [PATCH] sfc: Check null pointer of rx_queue->page_ring

On Mon, Dec 20, 2021 at 09:56:03PM +0800, Jiasheng Jiang wrote:
> Because of the possible failure of the kcalloc, it should be better to
> set rx_queue->page_ptr_mask to 0 when it happens in order to maintain
> the consistency.
> 
> Fixes: 5a6681e22c14 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver")
> Signed-off-by: Jiasheng Jiang <jiasheng@...as.ac.cn>
> ---
>  drivers/net/ethernet/sfc/rx_common.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c
> index 68fc7d317693..0983abc0cc5f 100644
> --- a/drivers/net/ethernet/sfc/rx_common.c
> +++ b/drivers/net/ethernet/sfc/rx_common.c
> @@ -150,7 +150,10 @@ static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
>  					    efx->rx_bufs_per_page);
>  	rx_queue->page_ring = kcalloc(page_ring_size,
>  				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
> -	rx_queue->page_ptr_mask = page_ring_size - 1;
> +	if (!rx_queue->page_ring)
> +		rx_queue->page_ptr_mask = 0;
> +	else
> +		rx_queue->page_ptr_mask = page_ring_size - 1;
>  }

Why not return an error?