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| author | Michal Kubeček <mkubecek@suse.cz> | 2016-12-02 09:33:41 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-30 05:49:28 +0200 |
| commit | 65d30f7545ffdddcf10a59f3e54b032c5ade2e9d (patch) | |
| tree | 2291f7cb2726778a8648f413662156478a73a73d /net/tipc/bearer.c | |
| parent | 9540baadb61ba5ed08832bb2a4cbfd876db37ff4 (diff) | |
| download | linux-stable-65d30f7545ffdddcf10a59f3e54b032c5ade2e9d.tar.gz linux-stable-65d30f7545ffdddcf10a59f3e54b032c5ade2e9d.tar.bz2 linux-stable-65d30f7545ffdddcf10a59f3e54b032c5ade2e9d.zip | |
tipc: check minimum bearer MTU
commit 3de81b758853f0b29c61e246679d20b513c4cfec upstream.
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 <mkubecek@suse.cz>
Reported-by: Qian Zhang (张谦) <zhangqian-c@360.cn>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.4:
- Adjust context
- NETDEV_GOING_DOWN and NETDEV_CHANGEMTU cases in net notifier were combined]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/tipc/bearer.c')
| -rw-r--r-- | net/tipc/bearer.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index 648f2a67f314..cb1381513c82 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -381,6 +381,10 @@ int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b, dev = dev_get_by_name(net, driver_name); if (!dev) return -ENODEV; + if (tipc_mtu_bad(dev, 0)) { + dev_put(dev); + return -EINVAL; + } /* Associate TIPC bearer with L2 bearer */ rcu_assign_pointer(b->media_ptr, dev); @@ -570,14 +574,19 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt, if (!b_ptr) return NOTIFY_DONE; - b_ptr->mtu = dev->mtu; - switch (evt) { case NETDEV_CHANGE: if (netif_carrier_ok(dev)) break; case NETDEV_GOING_DOWN: + tipc_reset_bearer(net, b_ptr); + break; case NETDEV_CHANGEMTU: + if (tipc_mtu_bad(dev, 0)) { + bearer_disable(net, b_ptr); + break; + } + b_ptr->mtu = dev->mtu; tipc_reset_bearer(net, b_ptr); break; case NETDEV_CHANGEADDR: |