Adding fdb entries pointing to the bridge device uses fdb_insert(),
which lacks various checks and does not respect added_by_user flag.
As a result, some inconsistent behavior can happen:
* Adding temporary entries succeeds but results in permanent entries.
* Same goes for "dynamic" and "use".
* Changing mac address of the bridge device causes deletion of
user-added entries.
* Replacing existing entries looks successful from userspace but actually
not, regardless of NLM_F_EXCL flag.
Use the same logic as other entries and fix them.
Fixes: 3741873b4f73 ("bridge: allow adding of fdb entries pointing to the
bridge device")
Signed-off-by: Toshiaki Makita <makita.toshi...@lab.ntt.co.jp>
---
net/bridge/br_fdb.c | 52 +++++++++++++++++++++++++++-------------------------
1 file changed, 27 insertions(+), 25 deletions(-)
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index c18080a..cd620fa 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -267,7 +267,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const
u8 *newaddr)
/* If old entry was unassociated with any port, then delete it. */
f = __br_fdb_get(br, br->dev->dev_addr, 0);
- if (f && f->is_local && !f->dst)
+ if (f && f->is_local && !f->dst && !f->added_by_user)
fdb_delete_local(br, NULL, f);
fdb_insert(br, NULL, newaddr, 0);
@@ -282,7 +282,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const
u8 *newaddr)
if (!br_vlan_should_use(v))
continue;
f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
- if (f && f->is_local && !f->dst)
+ if (f && f->is_local && !f->dst && !f->added_by_user)
fdb_delete_local(br, NULL, f);
fdb_insert(br, NULL, newaddr, v->vid);
}
@@ -764,20 +764,25 @@ out:
}
/* Update (create or replace) forwarding database entry */
-static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
- __u16 state, __u16 flags, __u16 vid)
+static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
+ const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
{
- struct net_bridge *br = source->br;
struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
struct net_bridge_fdb_entry *fdb;
bool modified = false;
/* If the port cannot learn allow only local and static entries */
- if (!(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
+ if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
!(source->state == BR_STATE_LEARNING ||
source->state == BR_STATE_FORWARDING))
return -EPERM;
+ if (!source && !(state & NUD_PERMANENT)) {
+ pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
+ br->dev->name);
+ return -EINVAL;
+ }
+
fdb = fdb_find(head, addr, vid);
if (fdb == NULL) {
if (!(flags & NLM_F_CREATE))
@@ -832,22 +837,28 @@ static int fdb_add_entry(struct net_bridge_port *source,
const __u8 *addr,
return 0;
}
-static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
- const unsigned char *addr, u16 nlh_flags, u16 vid)
+static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
+ struct net_bridge_port *p, const unsigned char *addr,
+ u16 nlh_flags, u16 vid)
{
int err = 0;
if (ndm->ndm_flags & NTF_USE) {
+ if (!p) {
+ pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not
supported\n",
+ br->dev->name);
+ return -EINVAL;
+ }
local_bh_disable();
rcu_read_lock();
- br_fdb_update(p->br, p, addr, vid, true);
+ br_fdb_update(br, p, addr, vid, true);
rcu_read_unlock();
local_bh_enable();
} else {
- spin_lock_bh(&p->br->hash_lock);
- err = fdb_add_entry(p, addr, ndm->ndm_state,
+ spin_lock_bh(&br->hash_lock);
+ err = fdb_add_entry(br, p, addr, ndm->ndm_state,
nlh_flags, vid);
- spin_unlock_bh(&p->br->hash_lock);
+ spin_unlock_bh(&br->hash_lock);
}
return err;
@@ -884,6 +895,7 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
dev->name);
return -EINVAL;
}
+ br = p->br;
vg = nbp_vlan_group(p);
}
@@ -895,15 +907,9 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
}
/* VID was specified, so use it. */
- if (dev->priv_flags & IFF_EBRIDGE)
- err = br_fdb_insert(br, NULL, addr, vid);
- else
- err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
+ err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
} else {
- if (dev->priv_flags & IFF_EBRIDGE)
- err = br_fdb_insert(br, NULL, addr, 0);
- else
- err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
+ err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
if (err || !vg || !vg->num_vlans)
goto out;
@@ -914,11 +920,7 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
list_for_each_entry(v, &vg->vlan_list, vlist) {
if (!br_vlan_should_use(v))
continue;
- if (dev->priv_flags & IFF_EBRIDGE)
- err = br_fdb_insert(br, NULL, addr, v->vid);
- else
- err = __br_fdb_add(ndm, p, addr, nlh_flags,
- v->vid);
+ err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
if (err)
goto out;
}
--
1.8.3.1
