On Wed, Mar 22, 2017 at 10:15:02AM +0800, gfree.w...@foxmail.com wrote: > From: Gao Feng <f...@ikuai8.com> > > Because these two functions return the nf_ct_helper_expectfn pointer > which should be protected by rcu lock. So it should makes sure the > caller should hold the rcu lock, not inside these functions. > > Signed-off-by: Gao Feng <f...@ikuai8.com> > --- > v2: Shorter subject, per Pablo > v1: Initial version > > net/netfilter/nf_conntrack_helper.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/net/netfilter/nf_conntrack_helper.c > b/net/netfilter/nf_conntrack_helper.c > index 6dc44d9..bce3d1f 100644 > --- a/net/netfilter/nf_conntrack_helper.c > +++ b/net/netfilter/nf_conntrack_helper.c > @@ -311,38 +311,36 @@ void nf_ct_helper_expectfn_unregister(struct > nf_ct_helper_expectfn *n) > } > EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister); > > +/* Caller should hold the rcu lock */ > struct nf_ct_helper_expectfn * > nf_ct_helper_expectfn_find_by_name(const char *name) > { > struct nf_ct_helper_expectfn *cur; > bool found = false; > > - rcu_read_lock(); > list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) { > if (!strcmp(cur->name, name)) { > found = true; > break; > } > } > - rcu_read_unlock(); > return found ? cur : NULL; > } > EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_name);
nf_ct_helper_expectfn_find_by_name() is called from ctnetlink, via ctnetlink_create_expect() and rcu read side lock is not held there. -- 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