linux-stable.git/drivers/net/vxlan.c, branch v5.8

vxlan: fix memleak of fdb

2020-08-01T18:49:18+00:00

When vxlan interface is deleted, all fdbs are deleted by vxlan_flush().
vxlan_flush() flushes fdbs but it doesn't delete fdb, which contains
all-zeros-mac because it is deleted by vxlan_uninit().
But vxlan_uninit() deletes only the fdb, which contains both all-zeros-mac
and default vni.
So, the fdb, which contains both all-zeros-mac and non-default vni
will not be deleted.

Test commands:
    ip link add vxlan0 type vxlan dstport 4789 external
    ip link set vxlan0 up
    bridge fdb add to 00:00:00:00:00:00 dst 172.0.0.1 dev vxlan0 via lo \
	    src_vni 10000 self permanent
    ip link del vxlan0

kmemleak reports as follows:
unreferenced object 0xffff9486b25ced88 (size 96):
  comm "bridge", pid 2151, jiffies 4294701712 (age 35506.901s)
  hex dump (first 32 bytes):
    02 00 00 00 ac 00 00 01 40 00 09 b1 86 94 ff ff  ........@.......
    46 02 00 00 00 00 00 00 a7 03 00 00 12 b5 6a 6b  F.............jk
  backtrace:
    [<00000000c10cf651>] vxlan_fdb_append.part.51+0x3c/0xf0 [vxlan]
    [<000000006b31a8d9>] vxlan_fdb_create+0x184/0x1a0 [vxlan]
    [<0000000049399045>] vxlan_fdb_update+0x12f/0x220 [vxlan]
    [<0000000090b1ef00>] vxlan_fdb_add+0x12a/0x1b0 [vxlan]
    [<0000000056633c2c>] rtnl_fdb_add+0x187/0x270
    [<00000000dd5dfb6b>] rtnetlink_rcv_msg+0x264/0x490
    [<00000000fc44dd54>] netlink_rcv_skb+0x4a/0x110
    [<00000000dff433e7>] netlink_unicast+0x18e/0x250
    [<00000000b87fb421>] netlink_sendmsg+0x2e9/0x400
    [<000000002ed55153>] ____sys_sendmsg+0x237/0x260
    [<00000000faa51c66>] ___sys_sendmsg+0x88/0xd0
    [<000000006c3982f1>] __sys_sendmsg+0x4e/0x80
    [<00000000a8f875d2>] do_syscall_64+0x56/0xe0
    [<000000003610eefa>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
unreferenced object 0xffff9486b1c40080 (size 128):
  comm "bridge", pid 2157, jiffies 4294701754 (age 35506.866s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 f8 dc 42 b2 86 94 ff ff  ..........B.....
    6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
  backtrace:
    [<00000000a2981b60>] vxlan_fdb_create+0x67/0x1a0 [vxlan]
    [<0000000049399045>] vxlan_fdb_update+0x12f/0x220 [vxlan]
    [<0000000090b1ef00>] vxlan_fdb_add+0x12a/0x1b0 [vxlan]
    [<0000000056633c2c>] rtnl_fdb_add+0x187/0x270
    [<00000000dd5dfb6b>] rtnetlink_rcv_msg+0x264/0x490
    [<00000000fc44dd54>] netlink_rcv_skb+0x4a/0x110
    [<00000000dff433e7>] netlink_unicast+0x18e/0x250
    [<00000000b87fb421>] netlink_sendmsg+0x2e9/0x400
    [<000000002ed55153>] ____sys_sendmsg+0x237/0x260
    [<00000000faa51c66>] ___sys_sendmsg+0x88/0xd0
    [<000000006c3982f1>] __sys_sendmsg+0x4e/0x80
    [<00000000a8f875d2>] do_syscall_64+0x56/0xe0
    [<000000003610eefa>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 3ad7a4b141eb ("vxlan: support fdb and learning in COLLECT_METADATA mode")
Signed-off-by: Taehee Yoo 
Acked-by: Roopa Prabhu 
Signed-off-by: David S. Miller

vxlan: Ensure FDB dump is performed under RCU

2020-07-29T19:04:54+00:00

The commit cited below removed the RCU read-side critical section from
rtnl_fdb_dump() which means that the ndo_fdb_dump() callback is invoked
without RCU protection.

This results in the following warning [1] in the VXLAN driver, which
relied on the callback being invoked from an RCU read-side critical
section.

Fix this by calling rcu_read_lock() in the VXLAN driver, as already done
in the bridge driver.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01521-g481007553ce6 #29 Not tainted
-----------------------------
drivers/net/vxlan.c:1379 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by bridge/166:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xea/0x1090

stack backtrace:
CPU: 1 PID: 166 Comm: bridge Not tainted 5.8.0-rc4-custom-01521-g481007553ce6 #29
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 vxlan_fdb_dump+0x51e/0x6d0
 rtnl_fdb_dump+0x4dc/0xad0
 netlink_dump+0x540/0x1090
 __netlink_dump_start+0x695/0x950
 rtnetlink_rcv_msg+0x802/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 __sys_sendto+0x279/0x3b0
 __x64_sys_sendto+0xe6/0x1a0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fe14fa2ade0
Code: Bad RIP value.
RSP: 002b:00007fff75bb5b88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00005614b1ba0020 RCX: 00007fe14fa2ade0
RDX: 000000000000011c RSI: 00007fff75bb5b90 RDI: 0000000000000003
RBP: 00007fff75bb5b90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00005614b1b89160
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Fixes: 5e6d24358799 ("bridge: netlink dump interface at par with brctl")
Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

vxlan: fix last fdb index during dump of fdb with nhid

2020-06-25T23:12:34+00:00

This patch fixes last saved fdb index in fdb dump handler when
handling fdb's with nhid.

Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries")
Signed-off-by: Roopa Prabhu 
Signed-off-by: David S. Miller

vxlan: Remove access to nexthop group struct

2020-06-10T20:20:20+00:00

vxlan driver should be using helpers to access nexthop struct
internals. Remove open check if whether nexthop is multipath in
favor of the existing nexthop_is_multipath helper. Add a new
helper, nexthop_has_v4, to cover the need to check has_v4 in
a group.

Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries")
Cc: Roopa Prabhu 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

nexthop: Fix fdb labeling for groups

2020-06-10T20:18:40+00:00

fdb nexthops are marked with a flag. For standalone nexthops, a flag was
added to the nh_info struct. For groups that flag was added to struct
nexthop when it should have been added to the group information. Fix
by removing the flag from the nexthop struct and adding a flag to nh_group
that mirrors nh_info and is really only a caching of the individual types.
Add a helper, nexthop_is_fdb, for use by the vxlan code and fixup the
internal code to use the flag from either nh_info or nh_group.

v2
- propagate fdb_nh in remove_nh_grp_entry

Fixes: 38428d68719c ("nexthop: support for fdb ecmp nexthops")
Cc: Roopa Prabhu 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: change addr_list_lock back to static key

2020-06-09T19:59:45+00:00

The dynamic key update for addr_list_lock still causes troubles,
for example the following race condition still exists:

CPU 0:				CPU 1:
(RCU read lock)			(RTNL lock)
dev_mc_seq_show()		netdev_update_lockdep_key()
				  -> lockdep_unregister_key()
 -> netif_addr_lock_bh()

because lockdep doesn't provide an API to update it atomically.
Therefore, we have to move it back to static keys and use subclass
for nest locking like before.

In commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key
changes"), I already reverted most parts of commit ab92d68fc22f
("net: core: add generic lockdep keys").

This patch reverts the rest and also part of commit f3b0a18bb6cb
("net: remove unnecessary variables and callback"). After this
patch, addr_list_lock changes back to using static keys and
subclasses to satisfy lockdep. Thanks to dev->lower_level, we do
not have to change back to ->ndo_get_lock_subclass().

And hopefully this reduces some syzbot lockdep noises too.

Reported-by: syzbot+f3a0e80c34b3fc28ac5e@syzkaller.appspotmail.com
Cc: Taehee Yoo 
Cc: Dmitry Vyukov 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

vxlan: fix dereference of nexthop group in nexthop update path

2020-06-01T19:06:26+00:00

fix dereference of nexthop group in fdb nexthop group
update validation path.

Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries")
Reported-by: Ido Schimmel 
Suggested-by: Ido Schimmel 
Signed-off-by: Roopa Prabhu 
Signed-off-by: David S. Miller

vxlan: Avoid infinite loop when suppressing NS messages with invalid options

2020-06-01T18:08:41+00:00

When proxy mode is enabled the vxlan device might reply to Neighbor
Solicitation (NS) messages on behalf of remote hosts.

In case the NS message includes the "Source link-layer address" option
[1], the vxlan device will use the specified address as the link-layer
destination address in its reply.

To avoid an infinite loop, break out of the options parsing loop when
encountering an option with length zero and disregard the NS message.

This is consistent with the IPv6 ndisc code and RFC 4886 which states
that "Nodes MUST silently discard an ND packet that contains an option
with length zero" [2].

[1] https://tools.ietf.org/html/rfc4861#section-4.3
[2] https://tools.ietf.org/html/rfc4861#section-4.6

Fixes: 4b29dba9c085 ("vxlan: fix nonfunctional neigh_reduce()")
Signed-off-by: Ido Schimmel 
Acked-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

vxlan: few locking fixes in nexthop event handler

2020-05-31T04:47:08+00:00

- remove fdb from nh_list before the rcu grace period
- protect fdb->vdev with rcu
- hold spin lock before destroying fdb

Fixes: c7cdbe2efc40 ("vxlan: support for nexthop notifiers")
Signed-off-by: Roopa Prabhu 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

vxlan: add check to prevent use of remote ip attributes with NDA_NH_ID

2020-05-31T04:47:08+00:00

NDA_NH_ID represents a remote ip or a group of remote ips.
It allows use of nexthop groups in lieu of a remote ip or a
list of remote ips supported by the fdb api.

Current code ignores the other remote ip attrs when NDA_NH_ID is
specified. In the spirit of strict checking, This commit adds a
check to explicitly return an error on incorrect usage.

Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries")
Signed-off-by: Roopa Prabhu 
Signed-off-by: David S. Miller