On Wed, Mar 15, 2023 at 03:06:21PM +0800, Jiasheng Jiang wrote:
> Add the check for the return value of skb_clone since it may return NULL
> pointer and cause NULL pointer dereference in send_pkt.
>
> Fixes: 18722c247023 ("Bluetooth: Enable 6LoWPAN support for BT LE devices")
> Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
> ---
> Changelog:
>
> v1 -> v2:
>
> 1. Modify the error handling in the loop.
I think that at a minimum this needs to be included in the patch description.
Or better, in it's own patch with it's own fixes tag.
It seems like a fundamental change to the error handling to me.
> ---
> net/bluetooth/6lowpan.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
> index 4eb1b3ced0d2..55ae2ff40efb 100644
> --- a/net/bluetooth/6lowpan.c
> +++ b/net/bluetooth/6lowpan.c
> @@ -477,19 +477,25 @@ static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
> int ret;
>
> local_skb = skb_clone(skb, GFP_ATOMIC);
> + if (!local_skb) {
> + err = -ENOMEM;
> + goto out;
> + }
>
> BT_DBG("xmit %s to %pMR type %u IP %pI6c chan %p",
> netdev->name,
> &pentry->chan->dst, pentry->chan->dst_type,
> &pentry->peer_addr, pentry->chan);
> ret = send_pkt(pentry->chan, local_skb, netdev);
> - if (ret < 0)
> - err = ret;
> -
> kfree_skb(local_skb);
> + if (ret < 0) {
> + err = ret;
> + goto out;
> + }
> }
> }
>
> +out:
> rcu_read_unlock();
>
> return err;
> --
> 2.25.1
>
