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Johannes Berg ee1c244219 genetlink: synchronize socket closing and family removal
In addition to the problem Jeff Layton reported, I looked at the code
and reproduced the same warning by subscribing and removing the genl
family with a socket still open. This is a fairly tricky race which
originates in the fact that generic netlink allows the family to go
away while sockets are still open - unlike regular netlink which has
a module refcount for every open socket so in general this cannot be
triggered.

Trying to resolve this issue by the obvious locking isn't possible as
it will result in deadlocks between unregistration and group unbind
notification (which incidentally lockdep doesn't find due to the home
grown locking in the netlink table.)

To really resolve this, introduce a "closing socket" reference counter
(for generic netlink only, as it's the only affected family) in the
core netlink code and use that in generic netlink to wait for all the
sockets that are being closed at the same time as a generic netlink
family is removed.

This fixes the race that when a socket is closed, it will should call
the unbind, but if the family is removed at the same time the unbind
will not find it, leading to the warning. The real problem though is
that in this case the unbind could actually find a new family that is
registered to have a multicast group with the same ID, and call its
mcast_unbind() leading to confusing.

Also remove the warning since it would still trigger, but is now no
longer a problem.

This also moves the code in af_netlink.c to before unreferencing the
module to avoid having the same problem in the normal non-genl case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-16 17:04:25 -05:00
Johannes Berg 5ad6300524 genetlink: disallow subscribing to unknown mcast groups
Jeff Layton reported that he could trigger the multicast unbind warning
in generic netlink using trinity. I originally thought it was a race
condition between unregistering the generic netlink family and closing
the socket, but there's a far simpler explanation: genetlink currently
allows subscribing to groups that don't (yet) exist, and the warning is
triggered when unsubscribing again while the group still doesn't exist.

Originally, I had a warning in the subscribe case and accepted it out of
userspace API concerns, but the warning was of course wrong and removed
later.

However, I now think that allowing userspace to subscribe to groups that
don't exist is wrong and could possibly become a security problem:
Consider a (new) genetlink family implementing a permission check in
the mcast_bind() function similar to the like the audit code does today;
it would be possible to bypass the permission check by guessing the ID
and subscribing to the group it exists. This is only possible in case a
family like that would be dynamically loaded, but it doesn't seem like a
huge stretch, for example wireless may be loaded when you plug in a USB
device.

To avoid this reject such subscription attempts.

If this ends up causing userspace issues we may need to add a workaround
in af_netlink to deny such requests but not return an error.

Reported-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-16 17:04:24 -05:00
David S. Miller dc97a1a947 genetlink: A genl_bind() to an out-of-range multicast group should not WARN().
Users can request to bind to arbitrary multicast groups, so warning
when the requested group number is out of range is not appropriate.

And with the warning removed, and the 'err' variable properly given
an initial value, we can remove 'found' altogether.

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-29 16:31:49 -05:00
Johannes Berg 023e2cfa36 netlink/genetlink: pass network namespace to bind/unbind
Netlink families can exist in multiple namespaces, and for the most
part multicast subscriptions are per network namespace. Thus it only
makes sense to have bind/unbind notifications per network namespace.

To achieve this, pass the network namespace of a given client socket
to the bind/unbind functions.

Also do this in generic netlink, and there also make sure that any
bind for multicast groups that only exist in init_net is rejected.
This isn't really a problem if it is accepted since a client in a
different namespace will never receive any notifications from such
a group, but it can confuse the family if not rejected (it's also
possible to silently (without telling the family) accept it, but it
would also have to be ignored on unbind so families that take any
kind of action on bind/unbind won't do unnecessary work for invalid
clients like that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-27 03:07:50 -05:00
Johannes Berg c380d9a7af genetlink: pass multicast bind/unbind to families
In order to make the newly fixed multicast bind/unbind
functionality in generic netlink, pass them down to the
appropriate family.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-27 02:20:23 -05:00
Johannes Berg 7d68536bed netlink: call unbind when releasing socket
Currently, netlink_unbind() is only called when the socket
explicitly unbinds, which limits its usefulness (luckily
there are no users of it yet anyway.)

Call netlink_unbind() also when a socket is released, so it
becomes possible to track listeners with this callback and
without also implementing a netlink notifier (and checking
netlink_has_listeners() in there.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-27 02:20:23 -05:00
Johannes Berg b10dcb3b94 netlink: update listeners directly when removing socket
The code is now confusing to read - first in one function down
(netlink_remove) any group subscriptions are implicitly removed
by calling __sk_del_bind_node(), but the subscriber database is
only updated far later by calling netlink_update_listeners().

Move the latter call to just after removal from the list so it
is easier to follow the code.

This also enables moving the locking inside the kernel-socket
conditional, which improves the normal socket destruction path.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-27 02:20:23 -05:00
Johannes Berg 02c81ab95d netlink: rename netlink_unbind() to netlink_undo_bind()
The new name is more expressive - this isn't a generic unbind
function but rather only a little undo helper for use only in
netlink_bind().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-27 02:20:23 -05:00
Thomas Graf a18e6a186f netlink: Don't reorder loads/stores before marking mmap netlink frame as available
Each mmap Netlink frame contains a status field which indicates
whether the frame is unused, reserved, contains data or needs to
be skipped. Both loads and stores may not be reordeded and must
complete before the status field is changed and another CPU might
pick up the frame for use. Use an smp_mb() to cover needs of both
types of callers to netlink_set_status(), callers which have been
reading data frame from the frame, and callers which have been
filling or releasing and thus writing to the frame.

- Example code path requiring a smp_rmb():
  memcpy(skb->data, (void *)hdr + NL_MMAP_HDRLEN, hdr->nm_len);
  netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED);

- Example code path requiring a smp_wmb():
  hdr->nm_uid	= from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid);
  hdr->nm_gid	= from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid);
  netlink_frame_flush_dcache(hdr);
  netlink_set_status(hdr, NL_MMAP_STATUS_VALID);

Fixes: f9c228 ("netlink: implement memory mapped recvmsg()")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18 12:35:55 -05:00
David Miller 4682a03586 netlink: Always copy on mmap TX.
Checking the file f_count and the nlk->mapped count is not completely
sufficient to prevent the mmap'd area contents from changing from
under us during netlink mmap sendmsg() operations.

Be careful to sample the header's length field only once, because this
could change from under us as well.

Fixes: 5fd96123ee ("netlink: implement memory mapped sendmsg()")
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
2014-12-18 12:35:23 -05:00
Daniel Borkmann 7f19fc5e0b netlink: use jhash as hashfn for rhashtable
For netlink, we shouldn't be using arch_fast_hash() as a hashing
discipline, but rather jhash() instead.

Since netlink sockets can be opened by any user, a local attacker
would be able to easily create collisions with the DPDK-derived
arch_fast_hash(), which trades off performance for security by
using crc32 CPU instructions on x86_64.

While it might have a legimite use case in other places, it should
be avoided in netlink context, though. As rhashtable's API is very
flexible, we could later on still decide on other hashing disciplines,
if legitimate.

Reference: http://thread.gmane.org/gmane.linux.kernel/1844123
Fixes: e341694e3e ("netlink: Convert netlink_lookup() to use RCU protected hash table")
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-10 15:17:45 -05:00
Al Viro c0371da604 put iov_iter into msghdr
Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09 16:29:03 -05:00
Al Viro 6ce8e9ce59 new helper: memcpy_from_msg()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-24 04:28:48 -05:00
Markus Elfring fcd4d35ecc netlink: Deletion of an unnecessary check before the function call "__module_get"
The __module_get() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-19 15:27:40 -05:00
David S. Miller 076ce44825 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/chelsio/cxgb4vf/sge.c
	drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c

sge.c was overlapping two changes, one to use the new
__dev_alloc_page() in net-next, and one to use s->fl_pg_order in net.

ixgbe_phy.c was a set of overlapping whitespace changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-14 01:01:12 -05:00
Thomas Graf 6eba82248e rhashtable: Drop gfp_flags arg in insert/remove functions
Reallocation is only required for shrinking and expanding and both rely
on a mutex for synchronization and callers of rhashtable_init() are in
non atomic context. Therefore, no reason to continue passing allocation
hints through the API.

Instead, use GFP_KERNEL and add __GFP_NOWARN | __GFP_NORETRY to allow
for silent fall back to vzalloc() without the OOM killer jumping in as
pointed out by Eric Dumazet and Eric W. Biederman.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13 15:18:40 -05:00
Herbert Xu 7b4ce23534 rhashtable: Add parent argument to mutex_is_held
Currently mutex_is_held can only test locks in the that are global
since it takes no arguments.  This prevents rhashtable from being
used in places where locks are lock, e.g., per-namespace locks.

This patch adds a parent field to mutex_is_held and rhashtable_params
so that local locks can be used (and tested).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13 15:13:05 -05:00
Herbert Xu 9712756620 netlink: Move mutex_is_held under PROVE_LOCKING
The rhashtable function mutex_is_held is only used when PROVE_LOCKING
is enabled.  This patch modifies netlink so that we can rhashtable.h
itself can later make mutex_is_held optional depending on PROVE_LOCKING.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13 15:13:05 -05:00
Hiroaki SHIMODA 6251edd932 netlink: Properly unbind in error conditions.
Even if netlink_kernel_cfg::unbind is implemented the unbind() method is
not called, because cfg->unbind is omitted in __netlink_kernel_create().
And fix wrong argument of test_bit() and off by one problem.

At this point, no unbind() method is implemented, so there is no real
issue.

Fixes: 4f52090052 ("netlink: have netlink per-protocol bind function return an error code.")
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-12 15:12:06 -05:00
David S. Miller 51f3d02b98 net: Add and use skb_copy_datagram_msg() helper.
This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".

When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.

Having a helper like this means there will be less places to touch
during that transformation.

Based upon descriptions and patch from Al Viro.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-05 16:46:40 -05:00
Thomas Graf 78fd1d0ab0 netlink: Re-add locking to netlink_lookup() and seq walker
The synchronize_rcu() in netlink_release() introduces unacceptable
latency. Reintroduce minimal lookup so we can drop the
synchronize_rcu() until socket destruction has been RCUfied.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Reported-and-tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-21 21:34:49 -04:00
Al Viro 24dff96a37 fix misuses of f_count() in ppp and netlink
we used to check for "nobody else could start doing anything with
that opened file" by checking that refcount was 2 or less - one
for descriptor table and one we'd acquired in fget() on the way to
wherever we are.  That was race-prone (somebody else might have
had a reference to descriptor table and do fget() just as we'd
been checking) and it had become flat-out incorrect back when
we switched to fget_light() on those codepaths - unlike fget(),
it doesn't grab an extra reference unless the descriptor table
is shared.  The same change allowed a race-free check, though -
we are safe exactly when refcount is less than 2.

It was a long time ago; pre-2.6.12 for ioctl() (the codepath leading
to ppp one) and 2.6.17 for sendmsg() (netlink one).  OTOH,
netlink hadn't grown that check until 3.9 and ppp used to live
in drivers/net, not drivers/net/ppp until 3.1.  The bug existed
well before that, though, and the same fix used to apply in old
location of file.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:17 -04:00
Thomas Graf 9ce12eb16f netlink: Annotate RCU locking for seq_file walker
Silences the following sparse warnings:
net/netlink/af_netlink.c:2926:21: warning: context imbalance in 'netlink_seq_start' - wrong count at exit
net/netlink/af_netlink.c:2972:13: warning: context imbalance in 'netlink_seq_stop' - unexpected unlock

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-14 15:13:40 -07:00
Daniel Borkmann 4e48ed883c netlink: reset network header before passing to taps
netlink doesn't set any network header offset thus when the skb is
being passed to tap devices via dev_queue_xmit_nit(), it emits klog
false positives due to it being unset like:

  ...
  [  124.990397] protocol 0000 is buggy, dev nlmon0
  [  124.990411] protocol 0000 is buggy, dev nlmon0
  ...

So just reset the network header before passing to the device; for
packet sockets that just means nothing will change - mac and net
offset hold the same value just as before.

Reported-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-07 16:02:58 -07:00
Thomas Graf 6c8f7e7083 netlink: hold nl_sock_hash_lock during diag dump
Although RCU protection would be possible during diag dump, doing
so allows for concurrent table mutations which can render the
in-table offset between individual Netlink messages invalid and
thus cause legitimate sockets to be skipped in the dump.

Since the diag dump is relatively low volume and consistency is
more important than performance, the table mutex is held during
dump.

Reported-by: Andrey Wagin <avagin@gmail.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Fixes: e341694e3e ("netlink: Convert netlink_lookup() to use RCU protected hash table")
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-06 19:17:44 -07:00
Eric Dumazet 67a24ac18b netlink: fix lockdep splats
With netlink_lookup() conversion to RCU, we need to use appropriate
rcu dereference in netlink_seq_socket_idx() & netlink_seq_next()

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: e341694e3e ("netlink: Convert netlink_lookup() to use RCU protected hash table")
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-04 22:58:06 -07:00
Thomas Graf e341694e3e netlink: Convert netlink_lookup() to use RCU protected hash table
Heavy Netlink users such as Open vSwitch spend a considerable amount of
time in netlink_lookup() due to the read-lock on nl_table_lock. Use of
RCU relieves the lock contention.

Makes use of the new resizable hash table to avoid locking on the
lookup.

The hash table will grow if entries exceeds 75% of table size up to a
total table size of 64K. It will automatically shrink if usage falls
below 30%.

Also splits nl_table_lock into a separate mutex to protect hash table
mutations and allow synchronize_rcu() to sleep while waiting for readers
during expansion and shrinking.

Before:
   9.16%  kpktgend_0  [openvswitch]      [k] masked_flow_lookup
   6.42%  kpktgend_0  [pktgen]           [k] mod_cur_headers
   6.26%  kpktgend_0  [pktgen]           [k] pktgen_thread_worker
   6.23%  kpktgend_0  [kernel.kallsyms]  [k] memset
   4.79%  kpktgend_0  [kernel.kallsyms]  [k] netlink_lookup
   4.37%  kpktgend_0  [kernel.kallsyms]  [k] memcpy
   3.60%  kpktgend_0  [openvswitch]      [k] ovs_flow_extract
   2.69%  kpktgend_0  [kernel.kallsyms]  [k] jhash2

After:
  15.26%  kpktgend_0  [openvswitch]      [k] masked_flow_lookup
   8.12%  kpktgend_0  [pktgen]           [k] pktgen_thread_worker
   7.92%  kpktgend_0  [pktgen]           [k] mod_cur_headers
   5.11%  kpktgend_0  [kernel.kallsyms]  [k] memset
   4.11%  kpktgend_0  [openvswitch]      [k] ovs_flow_extract
   4.06%  kpktgend_0  [kernel.kallsyms]  [k] _raw_spin_lock
   3.90%  kpktgend_0  [kernel.kallsyms]  [k] jhash2
   [...]
   0.67%  kpktgend_0  [kernel.kallsyms]  [k] netlink_lookup

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-02 19:49:38 -07:00
Tobias Klauser 74e83b23f2 netlink: Use PAGE_ALIGNED macro
Use PAGE_ALIGNED(...) instead of IS_ALIGNED(..., PAGE_SIZE).

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-31 22:05:28 -07:00
Varka Bhadram 498044bb2b netlink: remove bool varible
This patch removes the bool variable 'pass'.
If the swith case exist return true or return false.

Signed-off-by: Varka Bhadram <varkab@cdac.in>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-16 23:15:00 -07:00
David S. Miller 1a98c69af1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-16 14:09:34 -07:00
Ben Pfaff ac30ef832e netlink: Fix handling of error from netlink_dump().
netlink_dump() returns a negative errno value on error.  Until now,
netlink_recvmsg() directly recorded that negative value in sk->sk_err, but
that's wrong since sk_err takes positive errno values.  (This manifests as
userspace receiving a positive return value from the recv() system call,
falsely indicating success.) This bug was introduced in the commit that
started checking the netlink_dump() return value, commit b44d211 (netlink:
handle errors from netlink_dump()).

Multithreaded Netlink dumps are one way to trigger this behavior in
practice, as described in the commit message for the userspace workaround
posted here:
    http://openvswitch.org/pipermail/dev/2014-June/042339.html

This commit also fixes the same bug in netlink_poll(), introduced in commit
cd1df525d (netlink: add flow control for memory mapped I/O).

Signed-off-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-09 14:33:47 -07:00
Rami Rosen 46c9521fc2 netlink: Fix do_one_broadcast() prototype.
This patch changes the prototype of the do_one_broadcast() method so that it will return void.

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-07 20:52:49 -07:00
David S. Miller c99f7abf0e Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	include/net/inetpeer.h
	net/ipv6/output_core.c

Changes in net were fixing bugs in code removed in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-03 23:32:12 -07:00
Eric W. Biederman 2d7a85f4b0 netlink: Only check file credentials for implicit destinations
It was possible to get a setuid root or setcap executable to write to
it's stdout or stderr (which has been set made a netlink socket) and
inadvertently reconfigure the networking stack.

To prevent this we check that both the creator of the socket and
the currentl applications has permission to reconfigure the network
stack.

Unfortunately this breaks Zebra which always uses sendto/sendmsg
and creates it's socket without any privileges.

To keep Zebra working don't bother checking if the creator of the
socket has privilege when a destination address is specified.  Instead
rely exclusively on the privileges of the sender of the socket.

Note from Andy: This is exactly Eric's code except for some comment
clarifications and formatting fixes.  Neither I nor, I think, anyone
else is thrilled with this approach, but I'm hesitant to wait on a
better fix since 3.15 is almost here.

Note to stable maintainers: This is a mess.  An earlier series of
patches in 3.15 fix a rather serious security issue (CVE-2014-0181),
but they did so in a way that breaks Zebra.  The offending series
includes:

    commit aa4cf9452f
    Author: Eric W. Biederman <ebiederm@xmission.com>
    Date:   Wed Apr 23 14:28:03 2014 -0700

        net: Add variants of capable for use on netlink messages

If a given kernel version is missing that series of fixes, it's
probably worth backporting it and this patch.  if that series is
present, then this fix is critical if you care about Zebra.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-02 16:34:09 -07:00
Denis ChengRq 2f91abd451 genetlink: remove superfluous assignment
the local variable ops and n_ops were just read out from family,
and not changed, hence no need to assign back.

Validation functions should operate on const parameters and not
change anything.

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-02 10:36:18 -07:00
David S. Miller 5f013c9bc7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/altera/altera_sgdma.c
	net/netlink/af_netlink.c
	net/sched/cls_api.c
	net/sched/sch_api.c

The netlink conflict dealt with moving to netlink_capable() and
netlink_ns_capable() in the 'net' tree vs. supporting 'tc' operations
in non-init namespaces.  These were simple transformations from
netlink_capable to netlink_ns_capable.

The Altera driver conflict was simply code removal overlapping some
void pointer cast cleanups in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-12 13:19:14 -04:00
Eric W. Biederman 90f62cf30a net: Use netlink_ns_capable to verify the permisions of netlink messages
It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24 13:44:54 -04:00
Eric W. Biederman aa4cf9452f net: Add variants of capable for use on netlink messages
netlink_net_capable - The common case use, for operations that are safe on a network namespace
netlink_capable - For operations that are only known to be safe for the global root
netlink_ns_capable - The general case of capable used to handle special cases

__netlink_ns_capable - Same as netlink_ns_capable except taking a netlink_skb_parms instead of
		       the skbuff of a netlink message.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24 13:44:54 -04:00
Eric W. Biederman 5187cd055b netlink: Rename netlink_capable netlink_allowed
netlink_capable is a static internal function in af_netlink.c and we
have better uses for the name netlink_capable.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24 13:44:53 -04:00
Richard Guy Briggs 7774d5e03f netlink: implement unbind to netlink_setsockopt NETLINK_DROP_MEMBERSHIP
Call the per-protocol unbind function rather than bind function on
NETLINK_DROP_MEMBERSHIP in netlink_setsockopt().

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-22 21:42:26 -04:00
Richard Guy Briggs 4f52090052 netlink: have netlink per-protocol bind function return an error code.
Have the netlink per-protocol optional bind function return an int error code
rather than void to signal a failure.

This will enable netlink protocols to perform extra checks including
capabilities and permissions verifications when updating memberships in
multicast groups.

In netlink_bind() and netlink_setsockopt() the call to the per-protocol bind
function was moved above the multicast group update to prevent any access to
the multicast socket groups before checking with the per-protocol bind
function.  This will enable the per-protocol bind function to be used to check
permissions which could be denied before making them available, and to avoid
the messy job of undoing the addition should the per-protocol bind function
fail.

The netfilter subsystem seems to be the only one currently using the
per-protocol bind function.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-22 21:42:26 -04:00
David S. Miller 676d23690f net: Fix use after free by removing length arg from sk_data_ready callbacks.
Several spots in the kernel perform a sequence like:

	skb_queue_tail(&sk->s_receive_queue, skb);
	sk->sk_data_ready(sk, skb->len);

But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up.  So this skb->len access is potentially
to freed up memory.

Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.

And finally, no actual implementation of this callback actually uses
the length argument.  And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.

So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.

Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-11 16:15:36 -04:00
Eric Dumazet 9063e21fb0 netlink: autosize skb lengthes
One known problem with netlink is the fact that NLMSG_GOODSIZE is
really small on PAGE_SIZE==4096 architectures, and it is difficult
to know in advance what buffer size is used by the application.

This patch adds an automatic learning of the size.

First netlink message will still be limited to ~4K, but if user used
bigger buffers, then following messages will be able to use up to 16KB.

This speedups dump() operations by a large factor and should be safe
for legacy applications.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-10 13:56:26 -04:00
David S. Miller 67ddc87f16 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/wireless/ath/ath9k/recv.c
	drivers/net/wireless/mwifiex/pcie.c
	net/ipv6/sit.c

The SIT driver conflict consists of a bug fix being done by hand
in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper
was created (netdev_alloc_pcpu_stats()) which takes care of this.

The two wireless conflicts were overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-05 20:32:02 -05:00
Mike Pecovnik 46833a86f7 net: Fix permission check in netlink_connect()
netlink_sendmsg() was changed to prevent non-root processes from sending
messages with dst_pid != 0.
netlink_connect() however still only checks if nladdr->nl_groups is set.
This patch modifies netlink_connect() to check for the same condition.

Signed-off-by: Mike Pecovnik <mike.pecovnik@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-25 18:35:14 -05:00
Wang Yufen 23b4567291 netlink: fix checkpatch errors space and "foo *bar"
ERROR: spaces required and "(foo*)" should be "(foo *)"

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-17 16:57:28 -05:00
Steffen Hurrle 342dfc306f net: add build-time checks for msg->msg_name size
This is a follow-up patch to f3d3342602 ("net: rework recvmsg
handler msg_name and msg_namelen logic").

DECLARE_SOCKADDR validates that the structure we use for writing the
name information to is not larger than the buffer which is reserved
for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR
consistently in sendmsg code paths.

Signed-off-by: Steffen Hurrle <steffen@hurrle.net>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-18 23:04:16 -08:00
David S. Miller 39b6b2992f Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/jesse/openvswitch
Jesse Gross says:

====================
[GIT net-next] Open vSwitch

Open vSwitch changes for net-next/3.14. Highlights are:
 * Performance improvements in the mechanism to get packets to userspace
   using memory mapped netlink and skb zero copy where appropriate.
 * Per-cpu flow stats in situations where flows are likely to be shared
   across CPUs. Standard flow stats are used in other situations to save
   memory and allocation time.
 * A handful of code cleanups and rationalization.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-06 19:48:38 -05:00
Thomas Graf aae9f0e22c netlink: Avoid netlink mmap alloc if msg size exceeds frame size
An insufficent ring frame size configuration can lead to an
unnecessary skb allocation for every Netlink message. Check frame
size before taking the queue lock and allocating the skb and
re-check with lock to be safe.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
2014-01-06 15:52:06 -08:00
Thomas Graf bb9b18fb55 genl: Add genlmsg_new_unicast() for unicast message allocation
Allocates a new sk_buff large enough to cover the specified payload
plus required Netlink headers. Will check receiving socket for
memory mapped i/o capability and use it if enabled. Will fall back
to non-mapped skb if message size exceeds the frame size of the ring.

Signed-of-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
2014-01-06 15:51:53 -08:00