Davide Caratti <dcara...@redhat.com> writes:
> when the following command
>
> # tc actions replace action vlan pop index 100
>
> is run for the first time, and tcf_vlan_init() fails allocating struct
> tcf_vlan_params, tcf_vlan_cleanup() calls kfree_rcu(NULL, ...). This causes
> the following error:
>
[...]
> fix this in tcf_vlan_cleanup(), ensuring that kfree_rcu(p, ...) is called
> only when p is not NULL.
>
> Fixes: 4c5b9d9642c8 ("act_vlan: VLAN action rewrite to use RCU lock/unlock
> and update")
> Signed-off-by: Davide Caratti <dcara...@redhat.com>
> ---
> net/sched/act_vlan.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
> index e1a1b3f3983a..c2914e9a4a6f 100644
> --- a/net/sched/act_vlan.c
> +++ b/net/sched/act_vlan.c
> @@ -225,7 +225,8 @@ static void tcf_vlan_cleanup(struct tc_action *a)
> struct tcf_vlan_params *p;
>
> p = rcu_dereference_protected(v->vlan_p, 1);
> - kfree_rcu(p, rcu);
> + if (p)
> + kfree_rcu(p, rcu);
> }
>
> static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
Good catch. I think you can propagate the fix on the other actions
->cleanup(), where private parameters structure may not be present at
cleanup time, e.g. csum, ife.
