Mon, May 14, 2018 at 04:27:10PM CEST, vla...@mellanox.com wrote: >Return from action init function with reference to action taken, >even when overwriting existing action. > >Action init API initializes its fourth argument (pointer to pointer to >tc action) to either existing action with same index or newly created >action. In case of existing index(and bind argument is zero), init >function returns without incrementing action reference counter. Caller >of action init then proceeds working with action without actually >holding reference to it. This means that action could be deleted >concurrently. To prevent such scenario this patch changes action init
Be imperative to the codebase in the patch description. >behavior to always take reference to action before returning >successfully. Where's the balance? Who does the release instead? I'm probably missing something. > >Signed-off-by: Vlad Buslov <vla...@mellanox.com> >--- > net/sched/act_bpf.c | 8 ++++---- > net/sched/act_connmark.c | 5 +++-- > net/sched/act_csum.c | 8 ++++---- > net/sched/act_gact.c | 5 +++-- > net/sched/act_ife.c | 12 +++++------- > net/sched/act_ipt.c | 5 +++-- > net/sched/act_mirred.c | 5 ++--- > net/sched/act_nat.c | 5 +++-- > net/sched/act_pedit.c | 5 +++-- > net/sched/act_police.c | 8 +++----- > net/sched/act_sample.c | 8 +++----- > net/sched/act_simple.c | 5 +++-- > net/sched/act_skbedit.c | 5 +++-- > net/sched/act_skbmod.c | 8 +++----- > net/sched/act_tunnel_key.c | 8 +++----- > net/sched/act_vlan.c | 8 +++----- > 16 files changed, 51 insertions(+), 57 deletions(-) > >diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c >index 5d95c43..5554bf7 100644 >--- a/net/sched/act_bpf.c >+++ b/net/sched/act_bpf.c >@@ -311,9 +311,10 @@ static int tcf_bpf_init(struct net *net, struct nlattr >*nla, > if (bind) > return 0; > >- tcf_idr_release(*act, bind); >- if (!replace) >+ if (!replace) { >+ tcf_idr_release(*act, bind); > return -EEXIST; >+ } > } > > is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS]; [...] -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html