Re: [v2] net: thunderx: nicvf_main: Fix potential NULL pointer dereferences

From: Vadim Lomovtsev
Date: Thu Apr 05 2018 - 08:38:28 EST


Hi guys,

Please give me couple days to workout solution for this.
I'll post patch for this as soon as I done with my testing.

WBR,
Vadim

On Tue, Apr 03, 2018 at 05:04:23PM -0500, Gustavo A. R. Silva wrote:
> Add null check on kmalloc() return value in order to prevent
> a null pointer dereference.
>
> Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Add a null check on a second kmalloc a few lines below. Thanks to
> Eric Dumazet for pointing this out.
>
> drivers/net/ethernet/cavium/thunder/nicvf_main.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> index 1e9a31f..f7b5ca5 100644
> --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> @@ -1999,10 +1999,14 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> struct xcast_addr *xaddr;
>
> mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> + if (unlikely(!mc_list))
> + return;
> INIT_LIST_HEAD(&mc_list->list);
> netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> xaddr = kmalloc(sizeof(*xaddr),
> GFP_ATOMIC);
> + if (unlikely(!xaddr))
> + return;
> xaddr->addr =
> ether_addr_to_u64(ha->addr);
> list_add_tail(&xaddr->list,