linux-toradex.git/net/bridge, branch v3.14.3

bridge: Fix crash with vlan filtering and tcpdump

2014-03-28T21:14:02+00:00

When the vlan filtering is enabled on the bridge, but
the filter is not configured on the bridge device itself,
running tcpdump on the bridge device will result in a
an Oops with NULL pointer dereference.  The reason
is that br_pass_frame_up() will bypass the vlan
check because promisc flag is set.  It will then try
to get the table pointer and process the packet based
on the table.  Since the table pointer is NULL, we oops.
Catch this special condition in br_handle_vlan().

Reported-by: Toshiaki Makita 
CC: Toshiaki Makita 
Signed-off-by: Vlad Yasevich 
Acked-by: Toshiaki Makita 
Signed-off-by: David S. Miller

bridge: Fix handling stacked vlan tags

2014-03-28T20:33:09+00:00

If a bridge with vlan_filtering enabled receives frames with stacked
vlan tags, i.e., they have two vlan tags, br_vlan_untag() strips not
only the outer tag but also the inner tag.

br_vlan_untag() is called only from br_handle_vlan(), and in this case,
it is enough to set skb->vlan_tci to 0 here, because vlan_tci has already
been set before calling br_handle_vlan().

Signed-off-by: Toshiaki Makita 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

bridge: Fix inabillity to retrieve vlan tags when tx offload is disabled

2014-03-28T20:33:09+00:00

Bridge vlan code (br_vlan_get_tag()) assumes that all frames have vlan_tci
if they are tagged, but if vlan tx offload is manually disabled on bridge
device and frames are sent from vlan device on the bridge device, the tags
are embedded in skb->data and they break this assumption.
Extract embedded vlan tags and move them to vlan_tci at ingress.

Signed-off-by: Toshiaki Makita 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

bridge: multicast: enable snooping on general queries only

2014-03-12T03:22:10+00:00

Without this check someone could easily create a denial of service
by injecting multicast-specific queries to enable the bridge
snooping part if no real querier issuing periodic general queries
is present on the link which would result in the bridge wrongly
shutting down ports for multicast traffic as the bridge did not learn
about these listeners.

With this patch the snooping code is enabled upon receiving valid,
general queries only.

Signed-off-by: Linus Lüssing 
Signed-off-by: David S. Miller

bridge: multicast: add sanity check for general query destination

2014-03-12T03:22:10+00:00

General IGMP and MLD queries are supposed to have the multicast
link-local all-nodes address as their destination according to RFC2236
section 9, RFC3376 section 4.1.12/9.1, RFC2710 section 8 and RFC3810
section 5.1.15.

Without this check, such malformed IGMP/MLD queries can result in a
denial of service: The queries are ignored by most IGMP/MLD listeners
therefore they will not respond with an IGMP/MLD report. However,
without this patch these malformed MLD queries would enable the
snooping part in the bridge code, potentially shutting down the
according ports towards these hosts for multicast traffic as the
bridge did not learn about these listeners.

Reported-by: Jan Stancek 
Signed-off-by: Linus Lüssing 
Signed-off-by: David S. Miller

bridge: multicast: add sanity check for query source addresses

2014-03-06T01:40:24+00:00

MLD queries are supposed to have an IPv6 link-local source address
according to RFC2710, section 4 and RFC3810, section 5.1.14. This patch
adds a sanity check to ignore such broken MLD queries.

Without this check, such malformed MLD queries can result in a
denial of service: The queries are ignored by any MLD listener
therefore they will not respond with an MLD report. However,
without this patch these malformed MLD queries would enable the
snooping part in the bridge code, potentially shutting down the
according ports towards these hosts for multicast traffic as the
bridge did not learn about these listeners.

Reported-by: Jan Stancek 
Signed-off-by: Linus Lüssing 
Reviewed-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

bridge: Prevent possible race condition in br_fdb_change_mac_address

2014-02-10T22:34:34+00:00

br_fdb_change_mac_address() calls fdb_insert()/fdb_delete() without
br->hash_lock.

These hash list updates are racy with br_fdb_update()/br_fdb_cleanup().

Signed-off-by: Toshiaki Makita 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

bridge: Properly check if local fdb entry can be deleted when deleting vlan

2014-02-10T22:34:34+00:00

Vlan codes unconditionally delete local fdb entries.
We should consider the possibility that other ports have the same
address and vlan.

Example of problematic case:
  ip link set eth0 address 12:34:56:78:90:ab
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab
  bridge vlan add dev eth0 vid 10
  bridge vlan add dev eth1 vid 10
  bridge vlan add dev br0 vid 10 self
We will have fdb entry such that f->dst == eth0, f->vlan_id == 10 and
f->addr == 12:34:56:78:90:ab at this time.
Next, delete eth0 vlan 10.
  bridge vlan del dev eth0 vid 10
In this case, we still need the entry for br0, but it will be deleted.

Note that br0 needs the entry even though its mac address is not set
manually. To delete the entry with proper condition checking,
fdb_delete_local() is suitable to use.

Signed-off-by: Toshiaki Makita 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

bridge: Properly check if local fdb entry can be deleted in br_fdb_delete_by_port

2014-02-10T22:34:34+00:00

br_fdb_delete_by_port() doesn't care about vlan and mac address of the
bridge device.

As the check is almost the same as mac address changing, slightly modify
fdb_delete_local() and use it.

Note that we can always set added_by_user to 0 in fdb_delete_local() because
- br_fdb_delete_by_port() calls fdb_delete_local() for local entries
  regardless of its added_by_user. In this case, we have to check if another
  port has the same address and vlan, and if found, we have to create the
  entry (by changing dst). This is kernel-added entry, not user-added.
- br_fdb_changeaddr() doesn't call fdb_delete_local() for user-added entry.

Signed-off-by: Toshiaki Makita 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

bridge: Properly check if local fdb entry can be deleted in br_fdb_change_mac_address

2014-02-10T22:34:33+00:00

br_fdb_change_mac_address() doesn't check if the local entry has the
same address as any of bridge ports.
Although I'm not sure when it is beneficial, current implementation allow
the bridge device to receive any mac address of its ports.
To preserve this behavior, we have to check if the mac address of the
entry being deleted is identical to that of any port.

As this check is almost the same as that in br_fdb_changeaddr(), create
a common function fdb_delete_local() and call it from
br_fdb_changeadddr() and br_fdb_change_mac_address().

Signed-off-by: Toshiaki Makita 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller