On Tue, Mar 14, 2023 at 10:58:23PM +0800, Simon Horman wrote:
>On Mon, Mar 13, 2023 at 05:03:46PM +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>
>> ---
>> net/bluetooth/6lowpan.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
>> index 4eb1b3ced0d2..bf42a0b03e20 100644
>> --- a/net/bluetooth/6lowpan.c
>> +++ b/net/bluetooth/6lowpan.c
>> @@ -477,6 +477,10 @@ 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) {
>> + rcu_read_unlock();
>> + return -ENOMEM;
>> + }
>
> Further down in this loop an error is handled as follows,
> I wonder if that pattern is appropriate here too.
>
> ret = send_pkt(pentry->chan, local_skb, netdev);
> if (ret < 0)
> err = ret;
>
I think it should be better to return error here in order to avoid the
error being overwritten.
I will submit a v2 to modify the error handling here.
Thanks,
Jiang
