linux-stable.git/net/bridge, branch v3.16.45

net: bridge: fix old ioctl unlocked net device walk

2017-03-16T02:27:17+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: Ben Hutchings

bridge: multicast: restore perm router ports on multicast enable

2017-02-23T03:54:17+00:00

commit 7cb3f9214dfa443c1ccc2be637dcc6344cc203f0 upstream.

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: Ben Hutchings

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

2016-08-22T21:38:31+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: Ben Hutchings

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

2016-08-22T21:38:31+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: Ben Hutchings

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

2016-08-22T21:38:23+00:00

commit 0888d5f3c0f183ea6177355752ada433d370ac89 upstream.

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: Ben Hutchings

bridge: fix lockdep addr_list_lock false positive splat

2016-02-02T23:47:24+00:00

commit c6894dec8ea9ae05747124dce98b3b5c2e69b168 upstream.

After promisc mode management was introduced a bridge device could do
dev_set_promiscuity from its ndo_change_rx_flags() callback which in
turn can be called after the bridge's addr_list_lock has been taken
(e.g. by dev_uc_add). This causes a false positive lockdep splat because
the port interfaces' addr_list_lock is taken when br_manage_promisc()
runs after the bridge's addr list lock was already taken.
To remove the false positive introduce a custom bridge addr_list_lock
class and set it on bridge init.
A simple way to reproduce this is with the following:
$ brctl addbr br0
$ ip l add l br0 br0.100 type vlan id 100
$ ip l set br0 up
$ ip l set br0.100 up
$ echo 1 > /sys/class/net/br0/bridge/vlan_filtering
$ brctl addif br0 eth0
Splat:
[   43.684325] =============================================
[   43.684485] [ INFO: possible recursive locking detected ]
[   43.684636] 4.4.0-rc8+ #54 Not tainted
[   43.684755] ---------------------------------------------
[   43.684906] brctl/1187 is trying to acquire lock:
[   43.685047]  (_xmit_ETHER){+.....}, at: [] dev_set_rx_mode+0x1e/0x40
[   43.685460]  but task is already holding lock:
[   43.685618]  (_xmit_ETHER){+.....}, at: [] dev_uc_add+0x27/0x80
[   43.686015]  other info that might help us debug this:
[   43.686316]  Possible unsafe locking scenario:

[   43.686743]        CPU0
[   43.686967]        ----
[   43.687197]   lock(_xmit_ETHER);
[   43.687544]   lock(_xmit_ETHER);
[   43.687886] *** DEADLOCK ***

[   43.688438]  May be due to missing lock nesting notation

[   43.688882] 2 locks held by brctl/1187:
[   43.689134]  #0:  (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20
[   43.689852]  #1:  (_xmit_ETHER){+.....}, at: [] dev_uc_add+0x27/0x80
[   43.690575] stack backtrace:
[   43.690970] CPU: 0 PID: 1187 Comm: brctl Not tainted 4.4.0-rc8+ #54
[   43.691270] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
[   43.691770]  ffffffff826a25c0 ffff8800369fb8e0 ffffffff81360ceb ffffffff826a25c0
[   43.692425]  ffff8800369fb9b8 ffffffff810d0466 ffff8800369fb968 ffffffff81537139
[   43.693071]  ffff88003a08c880 0000000000000000 00000000ffffffff 0000000002080020
[   43.693709] Call Trace:
[   43.693931]  [] dump_stack+0x4b/0x70
[   43.694199]  [] __lock_acquire+0x1e46/0x1e90
[   43.694483]  [] ? netlink_broadcast_filtered+0x139/0x3e0
[   43.694789]  [] ? nlmsg_notify+0x5a/0xc0
[   43.695064]  [] lock_acquire+0xe5/0x1f0
[   43.695340]  [] ? dev_set_rx_mode+0x1e/0x40
[   43.695623]  [] _raw_spin_lock_bh+0x45/0x80
[   43.695901]  [] ? dev_set_rx_mode+0x1e/0x40
[   43.696180]  [] dev_set_rx_mode+0x1e/0x40
[   43.696460]  [] dev_set_promiscuity+0x3c/0x50
[   43.696750]  [] br_port_set_promisc+0x25/0x50 [bridge]
[   43.697052]  [] br_manage_promisc+0x8a/0xe0 [bridge]
[   43.697348]  [] br_dev_change_rx_flags+0x1e/0x20 [bridge]
[   43.697655]  [] __dev_set_promiscuity+0x132/0x1f0
[   43.697943]  [] __dev_set_rx_mode+0x82/0x90
[   43.698223]  [] dev_uc_add+0x5e/0x80
[   43.698498]  [] vlan_device_event+0x542/0x650 [8021q]
[   43.698798]  [] notifier_call_chain+0x5d/0x80
[   43.699083]  [] raw_notifier_call_chain+0x16/0x20
[   43.699374]  [] call_netdevice_notifiers_info+0x6e/0x80
[   43.699678]  [] call_netdevice_notifiers+0x16/0x20
[   43.699973]  [] br_add_if+0x47e/0x4c0 [bridge]
[   43.700259]  [] add_del_if+0x6e/0x80 [bridge]
[   43.700548]  [] br_dev_ioctl+0xaf/0xc0 [bridge]
[   43.700836]  [] dev_ifsioc+0x30c/0x3c0
[   43.701106]  [] dev_ioctl+0xf9/0x6f0
[   43.701379]  [] ? mntput_no_expire+0x5/0x450
[   43.701665]  [] ? mntput_no_expire+0xae/0x450
[   43.701947]  [] sock_do_ioctl+0x42/0x50
[   43.702219]  [] sock_ioctl+0x1e5/0x290
[   43.702500]  [] do_vfs_ioctl+0x2cb/0x5c0
[   43.702771]  [] SyS_ioctl+0x79/0x90
[   43.703033]  [] entry_SYSCALL_64_fastpath+0x16/0x7a

CC: Vlad Yasevich 
CC: Stephen Hemminger 
CC: Bridge list 
CC: Andy Gospodarek 
CC: Roopa Prabhu 
Fixes: 2796d0c648c9 ("bridge: Automatically manage port promiscuous mode.")
Reported-by: Andy Gospodarek 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques

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

2016-01-28T10:27:12+00:00

commit ff62198553e43cdffa9d539f6165d3e83f8a42bc upstream.

[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: Luis Henriques

bridge: mdb: fix delmdb state in the notification

2015-08-25T09:13:53+00:00

commit 7ae90a4f96486e3e20274afa1b8329802f5e1981 upstream.

Since mdb states were introduced when deleting an entry the state was
left as it was set in the delete request from the user which leads to
the following output when doing a monitor (for example):
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 temp
^^^
Note the "temp" state in the delete notification which is wrong since
the entry was permanent, the state in a delete is always reported as
"temp" regardless of the real state of the entry.

After this patch:
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent

There's one important note to make here that the state is actually not
matched when doing a delete, so one can delete a permanent entry by
stating "temp" in the end of the command, I've chosen this fix in order
not to break user-space tools which rely on this (incorrect) behaviour.

So to give an example after this patch and using the wrong state:
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 temp
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent

Note the state of the entry that got deleted is correct in the
notification.

Signed-off-by: Nikolay Aleksandrov 
Fixes: ccb1c31a7a87 ("bridge: add flags to distinguish permanent mdb entires")
Signed-off-by: David S. Miller 
Signed-off-by: Luis Henriques

bridge: mdb: fix double add notification

2015-08-12T08:48:29+00:00

commit 5ebc784625ea68a9570d1f70557e7932988cd1b4 upstream.

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: Luis Henriques

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

2015-08-10T16:10:18+00:00

commit f1158b74e54f2e2462ba5e2f45a118246d9d5b43 upstream.

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: Luis Henriques