linux-stable.git/net/tipc/link.c, branch linux-4.14.y

tipc: Fix potential OOB in tipc_link_proto_rcv()

2022-12-14T10:26:15+00:00

[ Upstream commit 743117a997bbd4840e827295c07e59bcd7f7caa3 ]

Fix the potential risk of OOB if skb_linearize() fails in
tipc_link_proto_rcv().

Fixes: 5cbb28a4bf65 ("tipc: linearize arriving NAME_DISTR and LINK_PROTO buffers")
Signed-off-by: YueHaibing 
Link: https://lore.kernel.org/r/20221203094635.29024-1-yuehaibing@huawei.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

tipc: improve size validations for received domain records

2022-02-11T07:43:36+00:00

commit 9aa422ad326634b76309e8ff342c246800621216 upstream.

The function tipc_mon_rcv() allows a node to receive and process
domain_record structs from peer nodes to track their views of the
network topology.

This patch verifies that the number of members in a received domain
record does not exceed the limit defined by MAX_MON_DOMAIN, something
that may otherwise lead to a stack overflow.

tipc_mon_rcv() is called from the function tipc_link_proto_rcv(), where
we are reading a 32 bit message data length field into a uint16.  To
avert any risk of bit overflow, we add an extra sanity check for this in
that function.  We cannot see that happen with the current code, but
future designers being unaware of this risk, may introduce it by
allowing delivery of very large (> 64k) sk buffers from the bearer
layer.  This potential problem was identified by Eric Dumazet.

This fixes CVE-2022-0435

Reported-by: Samuel Page 
Reported-by: Eric Dumazet 
Fixes: 35c55c9877f8 ("tipc: add neighbor monitoring framework")
Signed-off-by: Jon Maloy 
Reviewed-by: Xin Long 
Reviewed-by: Samuel Page 
Reviewed-by: Eric Dumazet 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

tipc: fix NULL deref in tipc_link_xmit()

2021-01-23T14:48:47+00:00

[ Upstream commit b77413446408fdd256599daf00d5be72b5f3e7c6 ]

The buffer list can have zero skb as following path:
tipc_named_node_up()->tipc_node_xmit()->tipc_link_xmit(), so
we need to check the list before casting an &sk_buff.

Fault report:
 [] tipc: Bulk publication failure
 [] general protection fault, probably for non-canonical [#1] PREEMPT [...]
 [] KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf]
 [] CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 5.10.0-rc4+ #2
 [] Hardware name: Bochs ..., BIOS Bochs 01/01/2011
 [] RIP: 0010:tipc_link_xmit+0xc1/0x2180
 [] Code: 24 b8 00 00 00 00 4d 39 ec 4c 0f 44 e8 e8 d7 0a 10 f9 48 [...]
 [] RSP: 0018:ffffc90000006ea0 EFLAGS: 00010202
 [] RAX: dffffc0000000000 RBX: ffff8880224da000 RCX: 1ffff11003d3cc0d
 [] RDX: 0000000000000019 RSI: ffffffff886007b9 RDI: 00000000000000c8
 [] RBP: ffffc90000007018 R08: 0000000000000001 R09: fffff52000000ded
 [] R10: 0000000000000003 R11: fffff52000000dec R12: ffffc90000007148
 [] R13: 0000000000000000 R14: 0000000000000000 R15: ffffc90000007018
 [] FS:  0000000000000000(0000) GS:ffff888037400000(0000) knlGS:000[...]
 [] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [] CR2: 00007fffd2db5000 CR3: 000000002b08f000 CR4: 00000000000006f0

Fixes: af9b028e270fd ("tipc: make media xmit call outside node spinlock context")
Acked-by: Jon Maloy 
Signed-off-by: Hoang Le 
Link: https://lore.kernel.org/r/20210108071337.3598-1-hoang.h.le@dektech.com.au
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

tipc: reduce risk of wakeup queue starvation

2020-01-27T13:46:41+00:00

[ Upstream commit 7c5b42055964f587e55bd87ef334c3a27e95d144 ]

In commit 365ad353c256 ("tipc: reduce risk of user starvation during
link congestion") we allowed senders to add exactly one list of extra
buffers to the link backlog queues during link congestion (aka
"oversubscription"). However, the criteria for when to stop adding
wakeup messages to the input queue when the overload abates is
inaccurate, and may cause starvation problems during very high load.

Currently, we stop adding wakeup messages after 10 total failed attempts
where we find that there is no space left in the backlog queue for a
certain importance level. The counter for this is accumulated across all
levels, which may lead the algorithm to leave the loop prematurely,
although there may still be plenty of space available at some levels.
The result is sometimes that messages near the wakeup queue tail are not
added to the input queue as they should be.

We now introduce a more exact algorithm, where we keep adding wakeup
messages to a level as long as the backlog queue has free slots for
the corresponding level, and stop at the moment there are no more such
slots or when there are no more wakeup messages to dequeue.

Fixes: 365ad35 ("tipc: reduce risk of user starvation during link congestion")
Reported-by: Tung Nguyen 
Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tipc: fix skb may be leaky in tipc_link_input

2019-12-05T14:37:57+00:00

[ Upstream commit 7384b538d3aed2ed49d3575483d17aeee790fb06 ]

When we free skb at tipc_data_input, we return a 'false' boolean.
Then, skb passed to subcalling tipc_link_input in tipc_link_rcv,


1303 int tipc_link_rcv:
...
1354    if (!tipc_data_input(l, skb, l->inputq))
1355        rc |= tipc_link_input(l, skb, l->inputq);


Fix it by simple changing to a 'true' boolean when skb is being free-ed.
Then, tipc_link_rcv will bypassed to subcalling tipc_link_input as above
condition.

Acked-by: Ying Xue 
Acked-by: Jon Maloy 
Signed-off-by: Hoang Le 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tipc: fix unlimited bundling of small messages

2019-10-07T16:55:20+00:00

[ Upstream commit e95584a889e1902fdf1ded9712e2c3c3083baf96 ]

We have identified a problem with the "oversubscription" policy in the
link transmission code.

When small messages are transmitted, and the sending link has reached
the transmit window limit, those messages will be bundled and put into
the link backlog queue. However, bundles of data messages are counted
at the 'CRITICAL' level, so that the counter for that level, instead of
the counter for the real, bundled message's level is the one being
increased.
Subsequent, to-be-bundled data messages at non-CRITICAL levels continue
to be tested against the unchanged counter for their own level, while
contributing to an unrestrained increase at the CRITICAL backlog level.

This leaves a gap in congestion control algorithm for small messages
that can result in starvation for other users or a "real" CRITICAL
user. Even that eventually can lead to buffer exhaustion & link reset.

We fix this by keeping a 'target_bskb' buffer pointer at each levels,
then when bundling, we only bundle messages at the same importance
level only. This way, we know exactly how many slots a certain level
have occupied in the queue, so can manage level congestion accurately.

By bundling messages at the same level, we even have more benefits. Let
consider this:
- One socket sends 64-byte messages at the 'CRITICAL' level;
- Another sends 4096-byte messages at the 'LOW' level;

When a 64-byte message comes and is bundled the first time, we put the
overhead of message bundle to it (+ 40-byte header, data copy, etc.)
for later use, but the next message can be a 4096-byte one that cannot
be bundled to the previous one. This means the last bundle carries only
one payload message which is totally inefficient, as for the receiver
also! Later on, another 64-byte message comes, now we make a new bundle
and the same story repeats...

With the new bundling algorithm, this will not happen, the 64-byte
messages will be bundled together even when the 4096-byte message(s)
comes in between. However, if the 4096-byte messages are sent at the
same level i.e. 'CRITICAL', the bundling algorithm will again cause the
same overhead.

Also, the same will happen even with only one socket sending small
messages at a rate close to the link transmit's one, so that, when one
message is bundled, it's transmitted shortly. Then, another message
comes, a new bundle is created and so on...

We will solve this issue radically by another patch.

Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion")
Reported-by: Hoang Le 
Acked-by: Jon Maloy 
Signed-off-by: Tuong Lien 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: don't reset stale broadcast send link

2017-08-21T20:37:45+00:00

When the broadcast send link after 100 attempts has failed to
transfer a packet to all peers, we consider it stale, and reset
it. Thereafter it needs to re-synchronize with the peers, something
currently done by just resetting and re-establishing all links to
all peers. This has turned out to be overkill, with potentially
unwanted consequences for the remaining cluster.

A closer analysis reveals that this can be done much simpler. When
this kind of failure happens, for reasons that may lie outside the
TIPC protocol, it is typically only one peer which is failing to
receive and acknowledge packets. It is hence sufficient to identify
and reset the links only to that peer to resolve the situation, without
having to reset the broadcast link at all. This solution entails a much
lower risk of negative consequences for the own node as well as for
the overall cluster.

We implement this change in this commit.

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

netlink: pass extended ACK struct to parsing functions

2017-04-13T17:58:22+00:00

Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

tipc: make replicast a user selectable option

2017-01-20T17:10:17+00:00

If the bearer carrying multicast messages supports broadcast, those
messages will be sent to all cluster nodes, irrespective of whether
these nodes host any actual destinations socket or not. This is clearly
wasteful if the cluster is large and there are only a few real
destinations for the message being sent.

In this commit we extend the eligibility of the newly introduced
"replicast" transmit option. We now make it possible for a user to
select which method he wants to be used, either as a mandatory setting
via setsockopt(), or as a relative setting where we let the broadcast
layer decide which method to use based on the ratio between cluster
size and the message's actual number of destination nodes.

In the latter case, a sending socket must stick to a previously
selected method until it enters an idle period of at least 5 seconds.
This eliminates the risk of message reordering caused by method change,
i.e., when changes to cluster size or number of destinations would
otherwise mandate a new method to be used.

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

tipc: introduce replicast as transport option for multicast

2017-01-20T17:10:17+00:00

TIPC multicast messages are currently carried over a reliable
'broadcast link', making use of the underlying media's ability to
transport packets as L2 broadcast or IP multicast to all nodes in
the cluster.

When the used bearer is lacking that ability, we can instead emulate
the broadcast service by replicating and sending the packets over as
many unicast links as needed to reach all identified destinations.
We now introduce a new TIPC link-level 'replicast' service that does
this.

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