linux/net/tipc, branch v4.9

tipc: check minimum bearer MTU

2016-12-02T19:03:20Z

Qian Zhang (张谦) reported a potential socket buffer overflow in tipc_msg_build() which is also known as CVE-2016-8632: due to insufficient checks, a buffer overflow can occur if MTU is too short for even tipc headers. As anyone can set device MTU in a user/net namespace, this issue can be abused by a regular user. As agreed in the discussion on Ben Hutchings' original patch, we should check the MTU at the moment a bearer is attached rather than for each processed packet. We also need to repeat the check when bearer MTU is adjusted to new device MTU. UDP case also needs a check to avoid overflow when calculating bearer MTU. Fixes: b97bf3fd8f6a ("[TIPC] Initial merge") Signed-off-by: Michal Kubecek Reported-by: Qian Zhang (张谦) Acked-by: Ying Xue Signed-off-by: David S. Miller

tipc: fix link statistics counter errors

2016-11-28T01:35:55Z

In commit e4bf4f76962b ("tipc: simplify packet sequence number handling") we changed the internal representation of the packet sequence number counters from u32 to u16, reflecting what is really sent over the wire. Since then some link statistics counters have been displaying incorrect values, partially because the counters meant to be used as sequence number snapshots are now used as direct counters, stored as u32, and partially because some counter updates are just missing in the code. In this commit we correct this in two ways. First, we base the displayed packet sent/received values on direct counters instead of as previously a calculated difference between current sequence number and a snapshot. Second, we add the missing updates of the counters. This change is compatible with the current netlink API, and requires no changes to the user space tools. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: resolve connection flow control compatibility problem

2016-11-26T02:38:16Z

In commit 10724cc7bb78 ("tipc: redesign connection-level flow control") we replaced the previous message based flow control with one based on 1k blocks. In order to ensure backwards compatibility the mechanism falls back to using message as base unit when it senses that the peer doesn't support the new algorithm. The default flow control window, i.e., how many units can be sent before the sender blocks and waits for an acknowledge (aka advertisement) is 512. This was tested against the previous version, which uses an acknowledge frequency of on ack per 256 received message, and found to work fine. However, we missed the fact that versions older than Linux 3.15 use an acknowledge frequency of 512, which is exactly the limit where a 4.6+ sender will stop and wait for acknowledge. This would also work fine if it weren't for the fact that if the first sent message on a 4.6+ server side is an empty SYNACK, this one is also is counted as a sent message, while it is not counted as a received message on a legacy 3.15-receiver. This leads to the sender always being one step ahead of the receiver, a scenario causing the sender to block after 512 sent messages, while the receiver only has registered 511 read messages. Hence, the legacy receiver is not trigged to send an acknowledge, with a permanently blocked sender as result. We solve this deadlock by simply allowing the sender to send one more message before it blocks, i.e., by a making minimal change to the condition used for determining connection congestion. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: improve sanity check for received domain records

2016-11-26T01:06:18Z

In commit 35c55c9877f8 ("tipc: add neighbor monitoring framework") we added a data area to the link monitor STATE messages under the assumption that previous versions did not use any such data area. For versions older than Linux 4.3 this assumption is not correct. In those version, all STATE messages sent out from a node inadvertently contain a 16 byte data area containing a string; -a leftover from previous RESET messages which were using this during the setup phase. This string serves no purpose in STATE messages, and should no be there. Unfortunately, this data area is delivered to the link monitor framework, where a sanity check catches that it is not a correct domain record, and drops it. It also issues a rate limited warning about the event. Since such events occur much more frequently than anticipated, we now choose to remove the warning in order to not fill the kernel log with useless contents. We also make the sanity check stricter, to further reduce the risk that such data is inavertently admitted. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix compatibility bug in link monitoring

2016-11-26T01:06:18Z

commit 817298102b0b ("tipc: fix link priority propagation") introduced a compatibility problem between TIPC versions newer than Linux 4.6 and those older than Linux 4.4. In versions later than 4.4, link STATE messages only contain a non-zero link priority value when the sender wants the receiver to change its priority. This has the effect that the receiver resets itself in order to apply the new priority. This works well, and is consistent with the said commit. However, in versions older than 4.4 a valid link priority is present in all sent link STATE messages, leading to cyclic link establishment and reset on the 4.6+ node. We fix this by adding a test that the received value should not only be valid, but also differ from the current value in order to cause the receiving link endpoint to reset. Reported-by: Amar Nv Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: eliminate obsolete socket locking policy description

2016-11-20T03:15:41Z

The comment block in socket.c describing the locking policy is obsolete, and does not reflect current reality. We remove it in this commit. Since the current locking policy is much simpler and follows a mainstream approach, we see no need to add a new description. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix broadcast link synchronization problem

2016-10-29T21:21:09Z

In commit 2d18ac4ba745 ("tipc: extend broadcast link initialization criteria") we tried to fix a problem with the initial synchronization of broadcast link acknowledge values. Unfortunately that solution is not sufficient to solve the issue. We have seen it happen that LINK_PROTOCOL/STATE packets with a valid non-zero unicast acknowledge number may bypass BCAST_PROTOCOL initialization, NAME_DISTRIBUTOR and other STATE packets with invalid broadcast acknowledge numbers, leading to premature opening of the broadcast link. When the bypassed packets finally arrive, they are inadvertently accepted, and the already correctly initialized acknowledge number in the broadcast receive link is overwritten by the invalid (zero) value of the said packets. After this the broadcast link goes stale. We now fix this by marking the packets where we know the acknowledge value is or may be invalid, and then ignoring the acks from those. To this purpose, we claim an unused bit in the header to indicate that the value is invalid. We set the bit to 1 in the initial BCAST_PROTOCOL synchronization packet and all initial ("bulk") NAME_DISTRIBUTOR packets, plus those LINK_PROTOCOL packets sent out before the broadcast links are fully synchronized. This minor protocol update is fully backwards compatible. Reported-by: John Thompson Tested-by: John Thompson Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: info leak in __tipc_nl_add_udp_addr()

2016-10-13T16:10:01Z

We should clear out the padding and unused struct members so that we don't expose stack information to userspace. Fixes: fdb3accc2c15 ('tipc: add the ability to get UDP options via netlink') Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller

tipc: fix possible memory leak in tipc_udp_enable()

2016-09-13T15:28:32Z

'ub' is malloced in tipc_udp_enable() and should be freed before leaving from the error handling cases, otherwise it will cause memory leak. Fixes: ba5aa84a2d22 ("tipc: split UDP nl address parsing") Signed-off-by: Wei Yongjun Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-09-12T22:52:44Z

Conflicts: drivers/net/ethernet/mediatek/mtk_eth_soc.c drivers/net/ethernet/qlogic/qed/qed_dcbx.c drivers/net/phy/Kconfig All conflicts were cases of overlapping commits. Signed-off-by: David S. Miller