linux-stable.git/include/net/net_namespace.h, branch linux-4.9.y

netns: provide pure entropy for net_hash_mix()

2019-04-17T06:36:46+00:00

[ Upstream commit 355b98553789b646ed97ad801a619ff898471b92 ]

net_hash_mix() currently uses kernel address of a struct net,
and is used in many places that could be used to reveal this
address to a patient attacker, thus defeating KASLR, for
the typical case (initial net namespace, &init_net is
not dynamically allocated)

I believe the original implementation tried to avoid spending
too many cycles in this function, but security comes first.

Also provide entropy regardless of CONFIG_NET_NS.

Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes")
Signed-off-by: Eric Dumazet 
Reported-by: Amit Klein 
Reported-by: Benny Pinkas 
Cc: Pavel Emelyanov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netfilter: ipv6: nf_defrag: reduce struct net memory waste

2018-08-24T11:12:26+00:00

[ Upstream commit 9ce7bc036ae4cfe3393232c86e9e1fea2153c237 ]

It is a waste of memory to use a full "struct netns_sysctl_ipv6"
while only one pointer is really used, considering netns_sysctl_ipv6
keeps growing.

Also, since "struct netns_frags" has cache line alignment,
it is better to move the frags_hdr pointer outside, otherwise
we spend a full cache line for this pointer.

This saves 192 bytes of memory per netns.

Fixes: c038a767cd69 ("ipv6: add a new namespace for nf_conntrack_reasm")
Signed-off-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

net: tcp: close sock if net namespace is exiting

2018-01-31T11:55:54+00:00

[ Upstream commit 4ee806d51176ba7b8ff1efd81f271d7252e03a1d ]

When a tcp socket is closed, if it detects that its net namespace is
exiting, close immediately and do not wait for FIN sequence.

For normal sockets, a reference is taken to their net namespace, so it will
never exit while the socket is open.  However, kernel sockets do not take a
reference to their net namespace, so it may begin exiting while the kernel
socket is still open.  In this case if the kernel socket is a tcp socket,
it will stay open trying to complete its close sequence.  The sock's dst(s)
hold a reference to their interface, which are all transferred to the
namespace's loopback interface when the real interfaces are taken down.
When the namespace tries to take down its loopback interface, it hangs
waiting for all references to the loopback interface to release, which
results in messages like:

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

These messages continue until the socket finally times out and closes.
Since the net namespace cleanup holds the net_mutex while calling its
registered pernet callbacks, any new net namespace initialization is
blocked until the current net namespace finishes exiting.

After this change, the tcp socket notices the exiting net namespace, and
closes immediately, releasing its dst(s) and their reference to the
loopback interface, which lets the net namespace continue exiting.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1711407
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=97811
Signed-off-by: Dan Streetman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netns: fix get_net_ns_by_fd(int pid) typo

2016-11-18T19:01:58+00:00

The argument to get_net_ns_by_fd() is a /proc/$PID/ns/net file
descriptor not a pid.  Fix the typo.

Signed-off-by: Stefan Hajnoczi 
Acked-by: Rami Rosen 
Signed-off-by: David S. Miller

netns: Add a limit on the number of net namespaces

2016-08-08T19:42:04+00:00

Acked-by: Kees Cook 
Signed-off-by: "Eric W. Biederman"

treewide: replace obsolete _refok by __ref

2016-08-02T21:31:41+00:00

There was only one use of __initdata_refok and __exit_refok

__init_refok was used 46 times against 82 for __ref.

Those definitions are obsolete since commit 312b1485fb50 ("Introduce new
section reference annotations tags: __ref, __refdata, __refconst")

This patch removes the following compatibility definitions and replaces
them treewide.

/* compatibility defines */
#define __init_refok     __ref
#define __initdata_refok __refdata
#define __exit_refok     __ref

I can also provide separate patches if necessary.
(One patch per tree and check in 1 month or 2 to remove old definitions)

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1466796271-3043-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick 
Cc: Ingo Molnar 
Cc: Sam Ravnborg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

netfilter: cttimeout: add netns support

2015-12-14T11:48:58+00:00

Add a per-netns list of timeout objects and adjust code to use it.

Signed-off-by: Pablo Neira Ayuso

netfilter: nfacct: per network namespace support

2015-08-07T09:50:56+00:00

- Move the nfnl_acct_list into the network namespace, initialize
  and destroy it per namespace
- Keep track of refcnt on nfacct objects, the old logic does not
  longer work with a per namespace list
- Adjust xt_nfacct to pass the namespace when registring objects

Signed-off-by: Andreas Schultz 
Signed-off-by: Pablo Neira Ayuso

net: include missing headers in net/net_namespace.h

2015-06-18T19:14:29+00:00

Include linux/idr.h and linux/skbuff.h since they are required by objects that
are declared in the net structure.

 struct net {
	...
	struct idr		netns_ids;
	...
	struct sk_buff_head	wext_nlevents;
	...

Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Eric W. Biederman

netns: make nsid_lock per net

2015-05-18T03:41:11+00:00

The spinlock is used to protect netns_ids which is per net,
so there is no need to use a global spinlock.

Cc: Nicolas Dichtel 
Signed-off-by: Cong Wang 
Acked-by: Nicolas Dichtel 
Signed-off-by: David S. Miller