linux-stable.git/net/bridge, branch v3.12.72

bridge: multicast: restore perm router ports on multicast enable

2016-11-28T21:22:29+00:00

[ Upstream commit 7cb3f9214dfa443c1ccc2be637dcc6344cc203f0 ]

Satish reported a problem with the perm multicast router ports not getting
reenabled after some series of events, in particular if it happens that the
multicast snooping has been disabled and the port goes to disabled state
then it will be deleted from the router port list, but if it moves into
non-disabled state it will not be re-added because the mcast snooping is
still disabled, and enabling snooping later does nothing.

Here are the steps to reproduce, setup br0 with snooping enabled and eth1
added as a perm router (multicast_router = 2):
1. $ echo 0 > /sys/class/net/br0/bridge/multicast_snooping
2. $ ip l set eth1 down
^ This step deletes the interface from the router list
3. $ ip l set eth1 up
^ This step does not add it again because mcast snooping is disabled
4. $ echo 1 > /sys/class/net/br0/bridge/multicast_snooping
5. $ bridge -d -s mdb show


At this point we have mcast enabled and eth1 as a perm router (value = 2)
but it is not in the router list which is incorrect.

After this change:
1. $ echo 0 > /sys/class/net/br0/bridge/multicast_snooping
2. $ ip l set eth1 down
^ This step deletes the interface from the router list
3. $ ip l set eth1 up
^ This step does not add it again because mcast snooping is disabled
4. $ echo 1 > /sys/class/net/br0/bridge/multicast_snooping
5. $ bridge -d -s mdb show
router ports on br0: eth1

Note: we can directly do br_multicast_enable_port for all because the
querier timer already has checks for the port state and will simply
expire if it's in blocking/disabled. See the comment added by
commit 9aa66382163e7 ("bridge: multicast: add a comment to
br_port_state_selection about blocking state")

Fixes: 561f1103a2b7 ("bridge: Add multicast_snooping sysfs toggle")
Reported-by: Satish Ashok 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

Bridge: Fix ipv6 mc snooping if bridge has no ipv6 address

2016-07-21T06:36:04+00:00

[ Upstream commit 0888d5f3c0f183ea6177355752ada433d370ac89 ]

The bridge is falsly dropping ipv6 mulitcast packets if there is:
 1. No ipv6 address assigned on the brigde.
 2. No external mld querier present.
 3. The internal querier enabled.

When the bridge fails to build mld queries, because it has no
ipv6 address, it slilently returns, but keeps the local querier enabled.
This specific case causes confusing packet loss.

Ipv6 multicast snooping can only work if:
 a) An external querier is present
 OR
 b) The bridge has an ipv6 address an is capable of sending own queries

Otherwise it has to forward/flood the ipv6 multicast traffic,
because snooping cannot work.

This patch fixes the issue by adding a flag to the bridge struct that
indicates that there is currently no ipv6 address assinged to the bridge
and returns a false state for the local querier in
__br_multicast_querier_exists().

Special thanks to Linus Lüssing.

Fixes: d1d81d4c3dd8 ("bridge: check return value of ipv6_dev_get_saddr()")
Signed-off-by: Daniel Danzberger 
Acked-by: Linus Lüssing 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

Revert "netfilter: ensure number of counters is >0 in do_replace()"

2016-07-21T06:35:48+00:00

commit d26e2c9ffa385dd1b646f43c1397ba12af9ed431 upstream.

This partially reverts commit 1086bbe97a07 ("netfilter: ensure number of
counters is >0 in do_replace()") in net/bridge/netfilter/ebtables.c.

Setting rules with ebtables does not work any more with 1086bbe97a07 place.

There is an error message and no rules set in the end.

e.g.

~# ebtables -t nat -A POSTROUTING --src 12:34:56:78:9a:bc -j DROP
Unable to update the kernel. Two possible causes:
1. Multiple ebtables programs were executing simultaneously. The ebtables
   userspace tool doesn't by default support multiple ebtables programs
running

Reverting the ebtables part of 1086bbe97a07 makes this work again.

Signed-off-by: Bernhard Thaler 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Jiri Slaby

netfilter: ensure number of counters is >0 in do_replace()

2016-07-21T06:35:47+00:00

commit 1086bbe97a074844188c6c988fa0b1a98c3ccbb9 upstream.

After improving setsockopt() coverage in trinity, I started triggering
vmalloc failures pretty reliably from this code path:

warn_alloc_failed+0xe9/0x140
__vmalloc_node_range+0x1be/0x270
vzalloc+0x4b/0x50
__do_replace+0x52/0x260 [ip_tables]
do_ipt_set_ctl+0x15d/0x1d0 [ip_tables]
nf_setsockopt+0x65/0x90
ip_setsockopt+0x61/0xa0
raw_setsockopt+0x16/0x60
sock_common_setsockopt+0x14/0x20
SyS_setsockopt+0x71/0xd0

It turns out we don't validate that the num_counters field in the
struct we pass in from userspace is initialized.

The same problem also exists in ebtables, arptables, ipv6, and the
compat variants.

Signed-off-by: Dave Jones 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Jiri Slaby

net: bridge: fix old ioctl unlocked net device walk

2016-05-19T09:00:12+00:00

[ Upstream commit 31ca0458a61a502adb7ed192bf9716c6d05791a5 ]

get_bridge_ifindices() is used from the old "deviceless" bridge ioctl
calls which aren't called with rtnl held. The comment above says that it is
called with rtnl but that is not really the case.
Here's a sample output from a test ASSERT_RTNL() which I put in
get_bridge_ifindices and executed "brctl show":
[  957.422726] RTNL: assertion failed at net/bridge//br_ioctl.c (30)
[  957.422925] CPU: 0 PID: 1862 Comm: brctl Tainted: G        W  O
4.6.0-rc4+ #157
[  957.423009] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.8.1-20150318_183358- 04/01/2014
[  957.423009]  0000000000000000 ffff880058adfdf0 ffffffff8138dec5
0000000000000400
[  957.423009]  ffffffff81ce8380 ffff880058adfe58 ffffffffa05ead32
0000000000000001
[  957.423009]  00007ffec1a444b0 0000000000000400 ffff880053c19130
0000000000008940
[  957.423009] Call Trace:
[  957.423009]  [] dump_stack+0x85/0xc0
[  957.423009]  []
br_ioctl_deviceless_stub+0x212/0x2e0 [bridge]
[  957.423009]  [] sock_ioctl+0x22b/0x290
[  957.423009]  [] do_vfs_ioctl+0x95/0x700
[  957.423009]  [] SyS_ioctl+0x79/0x90
[  957.423009]  [] entry_SYSCALL_64_fastpath+0x23/0xc1

Since it only reads bridge ifindices, we can use rcu to safely walk the net
device list. Also remove the wrong rtnl comment above.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

bridge: Only call /sbin/bridge-stp for the initial network namespace

2016-02-12T07:57:51+00:00

[ Upstream commit ff62198553e43cdffa9d539f6165d3e83f8a42bc ]

[I stole this patch from Eric Biederman. He wrote:]

> There is no defined mechanism to pass network namespace information
> into /sbin/bridge-stp therefore don't even try to invoke it except
> for bridge devices in the initial network namespace.
>
> It is possible for unprivileged users to cause /sbin/bridge-stp to be
> invoked for any network device name which if /sbin/bridge-stp does not
> guard against unreasonable arguments or being invoked twice on the
> same network device could cause problems.

[Hannes: changed patch using netns_eq]

Cc: Eric W. Biederman 
Signed-off-by: Eric W. Biederman 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

bridge: superfluous skb->nfct check in br_nf_dev_queue_xmit

2015-11-14T16:56:18+00:00

commit aff09ce303f83bd370772349238482ae422a2341 upstream.

Currently bridge can silently drop ipv4 fragments.
If node have loaded nf_defrag_ipv4 module but have no nf_conntrack_ipv4,
br_nf_pre_routing defragments incoming ipv4 fragments
but nfct check in br_nf_dev_queue_xmit does not allow re-fragment combined
packet back, and therefore it is dropped in br_dev_queue_push_xmit without
incrementing of any failcounters

It seems the only way to hit the ip_fragment code in the bridge xmit
path is to have a fragment list whose reassembled fragments go over
the mtu. This only happens if nf_defrag is enabled. Thanks to
Florian Westphal for providing feedback to clarify this.

Defragmentation ipv4 is required not only in conntracks but at least in
TPROXY target and socket match, therefore #ifdef is changed from
NF_CONNTRACK_IPV4 to NF_DEFRAG_IPV4

Signed-off-by: Vasily Averin 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Jiri Slaby

bridge: mdb: fix double add notification

2015-08-27T07:27:00+00:00

[ Upstream commit 5ebc784625ea68a9570d1f70557e7932988cd1b4 ]

Since the mdb add/del code was introduced there have been 2 br_mdb_notify
calls when doing br_mdb_add() resulting in 2 notifications on each add.

Example:
 Command: bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent
 Before patch:
 root@debian:~# bridge monitor all
 [MDB]dev br0 port eth1 grp 239.0.0.1 permanent
 [MDB]dev br0 port eth1 grp 239.0.0.1 permanent

 After patch:
 root@debian:~# bridge monitor all
 [MDB]dev br0 port eth1 grp 239.0.0.1 permanent

Signed-off-by: Nikolay Aleksandrov 
Fixes: cfd567543590 ("bridge: add support of adding and deleting mdb entries")
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

bridge: mdb: zero out the local br_ip variable before use

2015-08-27T07:26:57+00:00

[ Upstream commit f1158b74e54f2e2462ba5e2f45a118246d9d5b43 ]

Since commit b0e9a30dd669 ("bridge: Add vlan id to multicast groups")
there's a check in br_ip_equal() for a matching vlan id, but the mdb
functions were not modified to use (or at least zero it) so when an
entry was added it would have a garbage vlan id (from the local br_ip
variable in __br_mdb_add/del) and this would prevent it from being
matched and also deleted. So zero out the whole local ip var to protect
ourselves from future changes and also to fix the current bug, since
there's no vlan id support in the mdb uapi - use always vlan id 0.
Example before patch:
root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb
dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent
RTNETLINK answers: Invalid argument

After patch:
root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb
dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb

Signed-off-by: Nikolay Aleksandrov 
Fixes: b0e9a30dd669 ("bridge: Add vlan id to multicast groups")
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

bridge: fix br_stp_set_bridge_priority race conditions

2015-07-30T12:10:37+00:00

[ Upstream commit 2dab80a8b486f02222a69daca6859519e05781d9 ]

After the ->set() spinlocks were removed br_stp_set_bridge_priority
was left running without any protection when used via sysfs. It can
race with port add/del and could result in use-after-free cases and
corrupted lists. Tested by running port add/del in a loop with stp
enabled while setting priority in a loop, crashes are easily
reproducible.
The spinlocks around sysfs ->set() were removed in commit:
14f98f258f19 ("bridge: range check STP parameters")
There's also a race condition in the netlink priority support that is
fixed by this change, but it was introduced recently and the fixes tag
covers it, just in case it's needed the commit is:
af615762e972 ("bridge: add ageing_time, stp_state, priority over netlink")

Signed-off-by: Nikolay Aleksandrov 
Fixes: 14f98f258f19 ("bridge: range check STP parameters")
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby