linux-stable.git/net/tipc/core.c, branch linux-4.9.y

tipc: fix use-after-free in tipc_bcast_get_mode

2020-11-10T09:24:01+00:00

commit fdeba99b1e58ecd18c2940c453e19e4ef20ff591 upstream.

Syzbot has reported those issues as:

==================================================================
BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850

CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work

Thread 1's call trace:
[...]
  kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing
  tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721
  tipc_exit_net+0x24/0x270 net/tipc/core.c:112
[...]

Thread 2's call trace:
[...]
  tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase
has already been freed by Thread 1

  tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744
  tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752
  tipc_net_finalize net/tipc/net.c:141 [inline]
  tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131
  tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150
[...]

==================================================================
BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628
CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1f0/0x31e lib/dump_stack.c:118
 print_address_description+0x66/0x5a0 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344
 tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138
 tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
[...]
Freed by task 14058:
 save_stack mm/kasan/common.c:48 [inline]
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x220 mm/slab.c:3757
 tipc_exit_net+0x29/0x50 net/tipc/core.c:113
 ops_exit_list net/core/net_namespace.c:186 [inline]
 cleanup_net+0x708/0xba0 net/core/net_namespace.c:603
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Fix it by calling flush_scheduled_work() to make sure the
tipc_net_finalize_work() stopped before releasing bcbase object.

Reported-by: syzbot+6ea1f7a8df64596ef4d7@syzkaller.appspotmail.com
Reported-by: syzbot+e9cc557752ab126c1b99@syzkaller.appspotmail.com
Acked-by: Jon Maloy 
Signed-off-by: Hoang Huu Le 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: fix ordering of tipc module init and exit routine

2019-12-21T09:42:24+00:00

[ Upstream commit 9cf1cd8ee3ee09ef2859017df2058e2f53c5347f ]

In order to set/get/dump, the tipc uses the generic netlink
infrastructure. So, when tipc module is inserted, init function
calls genl_register_family().
After genl_register_family(), set/get/dump commands are immediately
allowed and these callbacks internally use the net_generic.
net_generic is allocated by register_pernet_device() but this
is called after genl_register_family() in the __init function.
So, these callbacks would use un-initialized net_generic.

Test commands:
    #SHELL1
    while :
    do
        modprobe tipc
        modprobe -rv tipc
    done

    #SHELL2
    while :
    do
        tipc link list
    done

Splat looks like:
[   59.616322][ T2788] kasan: CONFIG_KASAN_INLINE enabled
[   59.617234][ T2788] kasan: GPF could be caused by NULL-ptr deref or user memory access
[   59.618398][ T2788] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[   59.619389][ T2788] CPU: 3 PID: 2788 Comm: tipc Not tainted 5.4.0+ #194
[   59.620231][ T2788] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   59.621428][ T2788] RIP: 0010:tipc_bcast_get_broadcast_mode+0x131/0x310 [tipc]
[   59.622379][ T2788] Code: c7 c6 ef 8b 38 c0 65 ff 0d 84 83 c9 3f e8 d7 a5 f2 e3 48 8d bb 38 11 00 00 48 b8 00 00 00 00
[   59.622550][ T2780] NET: Registered protocol family 30
[   59.624627][ T2788] RSP: 0018:ffff88804b09f578 EFLAGS: 00010202
[   59.624630][ T2788] RAX: dffffc0000000000 RBX: 0000000000000011 RCX: 000000008bc66907
[   59.624631][ T2788] RDX: 0000000000000229 RSI: 000000004b3cf4cc RDI: 0000000000001149
[   59.624633][ T2788] RBP: ffff88804b09f588 R08: 0000000000000003 R09: fffffbfff4fb3df1
[   59.624635][ T2788] R10: fffffbfff50318f8 R11: ffff888066cadc18 R12: ffffffffa6cc2f40
[   59.624637][ T2788] R13: 1ffff11009613eba R14: ffff8880662e9328 R15: ffff8880662e9328
[   59.624639][ T2788] FS:  00007f57d8f7b740(0000) GS:ffff88806cc00000(0000) knlGS:0000000000000000
[   59.624645][ T2788] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   59.625875][ T2780] tipc: Started in single node mode
[   59.626128][ T2788] CR2: 00007f57d887a8c0 CR3: 000000004b140002 CR4: 00000000000606e0
[   59.633991][ T2788] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   59.635195][ T2788] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   59.636478][ T2788] Call Trace:
[   59.637025][ T2788]  tipc_nl_add_bc_link+0x179/0x1470 [tipc]
[   59.638219][ T2788]  ? lock_downgrade+0x6e0/0x6e0
[   59.638923][ T2788]  ? __tipc_nl_add_link+0xf90/0xf90 [tipc]
[   59.639533][ T2788]  ? tipc_nl_node_dump_link+0x318/0xa50 [tipc]
[   59.640160][ T2788]  ? mutex_lock_io_nested+0x1380/0x1380
[   59.640746][ T2788]  tipc_nl_node_dump_link+0x4fd/0xa50 [tipc]
[   59.641356][ T2788]  ? tipc_nl_node_reset_link_stats+0x340/0x340 [tipc]
[   59.642088][ T2788]  ? __skb_ext_del+0x270/0x270
[   59.642594][ T2788]  genl_lock_dumpit+0x85/0xb0
[   59.643050][ T2788]  netlink_dump+0x49c/0xed0
[   59.643529][ T2788]  ? __netlink_sendskb+0xc0/0xc0
[   59.644044][ T2788]  ? __netlink_dump_start+0x190/0x800
[   59.644617][ T2788]  ? __mutex_unlock_slowpath+0xd0/0x670
[   59.645177][ T2788]  __netlink_dump_start+0x5a0/0x800
[   59.645692][ T2788]  genl_rcv_msg+0xa75/0xe90
[   59.646144][ T2788]  ? __lock_acquire+0xdfe/0x3de0
[   59.646692][ T2788]  ? genl_family_rcv_msg_attrs_parse+0x320/0x320
[   59.647340][ T2788]  ? genl_lock_dumpit+0xb0/0xb0
[   59.647821][ T2788]  ? genl_unlock+0x20/0x20
[   59.648290][ T2788]  ? genl_parallel_done+0xe0/0xe0
[   59.648787][ T2788]  ? find_held_lock+0x39/0x1d0
[   59.649276][ T2788]  ? genl_rcv+0x15/0x40
[   59.649722][ T2788]  ? lock_contended+0xcd0/0xcd0
[   59.650296][ T2788]  netlink_rcv_skb+0x121/0x350
[   59.650828][ T2788]  ? genl_family_rcv_msg_attrs_parse+0x320/0x320
[   59.651491][ T2788]  ? netlink_ack+0x940/0x940
[   59.651953][ T2788]  ? lock_acquire+0x164/0x3b0
[   59.652449][ T2788]  genl_rcv+0x24/0x40
[   59.652841][ T2788]  netlink_unicast+0x421/0x600
[ ... ]

Fixes: 7e4369057806 ("tipc: fix a slab object leak")
Fixes: a62fbccecd62 ("tipc: make subscriber server support net namespace")
Signed-off-by: Taehee Yoo 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: change to use register_pernet_device

2019-07-10T07:55:40+00:00

[ Upstream commit c492d4c74dd3f87559883ffa0f94a8f1ae3fe5f5 ]

This patch is to fix a dst defcnt leak, which can be reproduced by doing:

  # ip net a c; ip net a s; modprobe tipc
  # ip net e s ip l a n eth1 type veth peer n eth1 netns c
  # ip net e c ip l s lo up; ip net e c ip l s eth1 up
  # ip net e s ip l s lo up; ip net e s ip l s eth1 up
  # ip net e c ip a a 1.1.1.2/8 dev eth1
  # ip net e s ip a a 1.1.1.1/8 dev eth1
  # ip net e c tipc b e m udp n u1 localip 1.1.1.2
  # ip net e s tipc b e m udp n u1 localip 1.1.1.1
  # ip net d c; ip net d s; rmmod tipc

and it will get stuck and keep logging the error:

  unregister_netdevice: waiting for lo to become free. Usage count = 1

The cause is that a dst is held by the udp sock's sk_rx_dst set on udp rx
path with udp_early_demux == 1, and this dst (eventually holding lo dev)
can't be released as bearer's removal in tipc pernet .exit happens after
lo dev's removal, default_device pernet .exit.

 "There are two distinct types of pernet_operations recognized: subsys and
  device.  At creation all subsys init functions are called before device
  init functions, and at destruction all device exit functions are called
  before subsys exit function."

So by calling register_pernet_device instead to register tipc_net_ops, the
pernet .exit() will be invoked earlier than loopback dev's removal when a
netns is being destroyed, as fou/gue does.

Note that vxlan and geneve udp tunnels don't have this issue, as the udp
sock is released in their device ndo_stop().

This fix is also necessary for tipc dst_cache, which will hold dsts on tx
path and I will introduce in my next patch.

Reported-by: Li Shuang 
Signed-off-by: Xin Long 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: fix modprobe tipc failed after switch order of device registration

2019-06-11T10:22:36+00:00

commit 526f5b851a96566803ee4bee60d0a34df56c77f8 upstream.

Error message printed:
modprobe: ERROR: could not insert 'tipc': Address family not
supported by protocol.
when modprobe tipc after the following patch: switch order of
device registration, commit 7e27e8d6130c
("tipc: switch order of device registration to fix a crash")

Because sock_create_kern(net, AF_TIPC, ...) called by
tipc_topsrv_create_listener() in the initialization process
of tipc_init_net(), so tipc_socket_init() must be execute before that.
Meanwhile, tipc_net_id need to be initialized when sock_create()
called, and tipc_socket_init() is no need to be called for each namespace.

I add a variable tipc_topsrv_net_ops, and split the
register_pernet_subsys() of tipc into two parts, and split
tipc_socket_init() with initialization of pernet params.

By the way, I fixed resources rollback error when tipc_bcast_init()
failed in tipc_init_net().

Fixes: 7e27e8d6130c ("tipc: switch order of device registration to fix a crash")
Signed-off-by: Junwei Hu 
Reported-by: Wang Wang 
Reported-by: syzbot+1e8114b61079bfe9cbc5@syzkaller.appspotmail.com
Reviewed-by: Kang Zhou 
Reviewed-by: Suanming Mou 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Revert "tipc: fix modprobe tipc failed after switch order of device registration"

2019-06-11T10:22:35+00:00

commit 5593530e56943182ebb6d81eca8a3be6db6dbba4 upstream.

This reverts commit 532b0f7ece4cb2ffd24dc723ddf55242d1188e5e.

More revisions coming up.

Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: fix modprobe tipc failed after switch order of device registration

2019-05-25T16:26:44+00:00

[ Upstream commit 532b0f7ece4cb2ffd24dc723ddf55242d1188e5e ]

Error message printed:
modprobe: ERROR: could not insert 'tipc': Address family not
supported by protocol.
when modprobe tipc after the following patch: switch order of
device registration, commit 7e27e8d6130c
("tipc: switch order of device registration to fix a crash")

Because sock_create_kern(net, AF_TIPC, ...) is called by
tipc_topsrv_create_listener() in the initialization process
of tipc_net_ops, tipc_socket_init() must be execute before that.

I move tipc_socket_init() into function tipc_init_net().

Fixes: 7e27e8d6130c
("tipc: switch order of device registration to fix a crash")
Signed-off-by: Junwei Hu 
Reported-by: Wang Wang 
Reviewed-by: Kang Zhou 
Reviewed-by: Suanming Mou 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: switch order of device registration to fix a crash

2019-05-25T16:26:44+00:00

[ Upstream commit 7e27e8d6130c5e88fac9ddec4249f7f2337fe7f8 ]

When tipc is loaded while many processes try to create a TIPC socket,
a crash occurs:
 PANIC: Unable to handle kernel paging request at virtual
 address "dfff20000000021d"
 pc : tipc_sk_create+0x374/0x1180 [tipc]
 lr : tipc_sk_create+0x374/0x1180 [tipc]
   Exception class = DABT (current EL), IL = 32 bits
 Call trace:
  tipc_sk_create+0x374/0x1180 [tipc]
  __sock_create+0x1cc/0x408
  __sys_socket+0xec/0x1f0
  __arm64_sys_socket+0x74/0xa8
 ...

This is due to race between sock_create and unfinished
register_pernet_device. tipc_sk_insert tries to do
"net_generic(net, tipc_net_id)".
but tipc_net_id is not initialized yet.

So switch the order of the two to close the race.

This can be reproduced with multiple processes doing socket(AF_TIPC, ...)
and one process doing module removal.

Fixes: a62fbccecd62 ("tipc: make subscriber server support net namespace")
Signed-off-by: Junwei Hu 
Reported-by: Wang Wang 
Reviewed-by: Xiaogang Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: add neighbor monitoring framework

2016-06-15T21:06:28+00:00

TIPC based clusters are by default set up with full-mesh link
connectivity between all nodes. Those links are expected to provide
a short failure detection time, by default set to 1500 ms. Because
of this, the background load for neighbor monitoring in an N-node
cluster increases with a factor N on each node, while the overall
monitoring traffic through the network infrastructure increases at
a ~(N * (N - 1)) rate. Experience has shown that such clusters don't
scale well beyond ~100 nodes unless we significantly increase failure
discovery tolerance.

This commit introduces a framework and an algorithm that drastically
reduces this background load, while basically maintaining the original
failure detection times across the whole cluster. Using this algorithm,
background load will now grow at a rate of ~(2 * sqrt(N)) per node, and
at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will
now have to actively monitor 38 neighbors in a 400-node cluster, instead
of as before 399.

This "Overlapping Ring Supervision Algorithm" is completely distributed
and employs no centralized or coordinated state. It goes as follows:

- Each node makes up a linearly ascending, circular list of all its N
  known neighbors, based on their TIPC node identity. This algorithm
  must be the same on all nodes.

- The node then selects the next M = sqrt(N) - 1 nodes downstream from
  itself in the list, and chooses to actively monitor those. This is
  called its "local monitoring domain".

- It creates a domain record describing the monitoring domain, and
  piggy-backs this in the data area of all neighbor monitoring messages
  (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in
  the cluster eventually (default within 400 ms) will learn about
  its monitoring domain.

- Whenever a node discovers a change in its local domain, e.g., a node
  has been added or has gone down, it creates and sends out a new
  version of its node record to inform all neighbors about the change.

- A node receiving a domain record from anybody outside its local domain
  matches this against its own list (which may not look the same), and
  chooses to not actively monitor those members of the received domain
  record that are also present in its own list. Instead, it relies on
  indications from the direct monitoring nodes if an indirectly
  monitored node has gone up or down. If a node is indicated lost, the
  receiving node temporarily activates its own direct monitoring towards
  that node in order to confirm, or not, that it is actually gone.

- Since each node is actively monitoring sqrt(N) downstream neighbors,
  each node is also actively monitored by the same number of upstream
  neighbors. This means that all non-direct monitoring nodes normally
  will receive sqrt(N) indications that a node is gone.

- A major drawback with ring monitoring is how it handles failures that
  cause massive network partitionings. If both a lost node and all its
  direct monitoring neighbors are inside the lost partition, the nodes in
  the remaining partition will never receive indications about the loss.
  To overcome this, each node also chooses to actively monitor some
  nodes outside its local domain. Those nodes are called remote domain
  "heads", and are selected in such a way that no node in the cluster
  will be more than two direct monitoring hops away. Because of this,
  each node, apart from monitoring the member of its local domain, will
  also typically monitor sqrt(N) remote head nodes.

- As an optimization, local list status, domain status and domain
  records are marked with a generation number. This saves senders from
  unnecessarily conveying  unaltered domain records, and receivers from
  performing unneeded re-adaptations of their node monitoring list, such
  as re-assigning domain heads.

- As a measure of caution we have added the possibility to disable the
  new algorithm through configuration. We do this by keeping a threshold
  value for the cluster size; a cluster that grows beyond this value
  will switch from full-mesh to ring monitoring, and vice versa when
  it shrinks below the value. This means that if the threshold is set to
  a value larger than any anticipated cluster size (default size is 32)
  the new algorithm is effectively disabled. A patch set for altering the
  threshold value and for listing the table contents will follow shortly.

- This change is fully backwards compatible.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: redesign connection-level flow control

2016-05-03T19:51:16+00:00

There are two flow control mechanisms in TIPC; one at link level that
handles network congestion, burst control, and retransmission, and one
at connection level which' only remaining task is to prevent overflow
in the receiving socket buffer. In TIPC, the latter task has to be
solved end-to-end because messages can not be thrown away once they
have been accepted and delivered upwards from the link layer, i.e, we
can never permit the receive buffer to overflow.

Currently, this algorithm is message based. A counter in the receiving
socket keeps track of number of consumed messages, and sends a dedicated
acknowledge message back to the sender for each 256 consumed message.
A counter at the sending end keeps track of the sent, not yet
acknowledged messages, and blocks the sender if this number ever reaches
512 unacknowledged messages. When the missing acknowledge arrives, the
socket is then woken up for renewed transmission. This works well for
keeping the message flow running, as it almost never happens that a
sender socket is blocked this way.

A problem with the current mechanism is that it potentially is very
memory consuming. Since we don't distinguish between small and large
messages, we have to dimension the socket receive buffer according
to a worst-case of both. I.e., the window size must be chosen large
enough to sustain a reasonable throughput even for the smallest
messages, while we must still consider a scenario where all messages
are of maximum size. Hence, the current fix window size of 512 messages
and a maximum message size of 66k results in a receive buffer of 66 MB
when truesize(66k) = 131k is taken into account. It is possible to do
much better.

This commit introduces an algorithm where we instead use 1024-byte
blocks as base unit. This unit, always rounded upwards from the
actual message size, is used when we advertise windows as well as when
we count and acknowledge transmitted data. The advertised window is
based on the configured receive buffer size in such a way that even
the worst-case truesize/msgsize ratio always is covered. Since the
smallest possible message size (from a flow control viewpoint) now is
1024 bytes, we can safely assume this ratio to be less than four, which
is the value we are now using.

This way, we have been able to reduce the default receive buffer size
from 66 MB to 2 MB with maintained performance.

In order to keep this solution backwards compatible, we introduce a
new capability bit in the discovery protocol, and use this throughout
the message sending/reception path to always select the right unit.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: make dist queue pernet

2016-04-11T19:22:20+00:00

Nametable updates received from the network that cannot be applied
immediately are placed on a defer queue. This queue is global to the
TIPC module, which might cause problems when using TIPC in containers.
To prevent nametable updates from escaping into the wrong namespace,
we make the queue pernet instead.

Signed-off-by: Erik Hugne 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller