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Pablo Neira Ayuso 20e1db19db netlink: fix possible spoofing from non-root processes
Non-root user-space processes can send Netlink messages to other
processes that are well-known for being subscribed to Netlink
asynchronous notifications. This allows ilegitimate non-root
process to send forged messages to Netlink subscribers.

The userspace process usually verifies the legitimate origin in
two ways:

a) Socket credentials. If UID != 0, then the message comes from
   some ilegitimate process and the message needs to be dropped.

b) Netlink portID. In general, portID == 0 means that the origin
   of the messages comes from the kernel. Thus, discarding any
   message not coming from the kernel.

However, ctnetlink sets the portID in event messages that has
been triggered by some user-space process, eg. conntrack utility.
So other processes subscribed to ctnetlink events, eg. conntrackd,
know that the event was triggered by some user-space action.

Neither of the two ways to discard ilegitimate messages coming
from non-root processes can help for ctnetlink.

This patch adds capability validation in case that dst_pid is set
in netlink_sendmsg(). This approach is aggressive since existing
applications using any Netlink bus to deliver messages between
two user-space processes will break. Note that the exception is
NETLINK_USERSOCK, since it is reserved for netlink-to-netlink
userspace communication.

Still, if anyone wants that his Netlink bus allows netlink-to-netlink
userspace, then they can set NL_NONROOT_SEND. However, by default,
I don't think it makes sense to allow to use NETLINK_ROUTE to
communicate two processes that are sending no matter what information
that is not related to link/neighbouring/routing. They should be using
NETLINK_USERSOCK instead for that.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-24 13:36:09 -04:00
Eric Dumazet e0e3cea46d af_netlink: force credentials passing [CVE-2012-3520]
Pablo Neira Ayuso discovered that avahi and
potentially NetworkManager accept spoofed Netlink messages because of a
kernel bug.  The kernel passes all-zero SCM_CREDENTIALS ancillary data
to the receiver if the sender did not provide such data, instead of not
including any such data at all or including the correct data from the
peer (as it is the case with AF_UNIX).

This bug was introduced in commit 16e5726269
(af_unix: dont send SCM_CREDENTIALS by default)

This patch forces passing credentials for netlink, as
before the regression.

Another fix would be to not add SCM_CREDENTIALS in
netlink messages if not provided by the sender, but it
might break some programs.

With help from Florian Weimer & Petr Matousek

This issue is designated as CVE-2012-3520

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-21 14:53:01 -07:00
WANG Cong 320f5ea0ce genetlink: define lockdep_genl_is_held() when CONFIG_LOCKDEP
lockdep_is_held() is defined when CONFIG_LOCKDEP, not CONFIG_PROVE_LOCKING.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jesse Gross <jesse@nicira.com>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-24 00:01:30 -07:00
Ben Hutchings 2c53040f01 net: Fix (nearly-)kernel-doc comments for various functions
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 23:13:45 -07:00
Pablo Neira Ayuso 03292745b0 netlink: add nlk->netlink_bind hook for module auto-loading
This patch adds a hook in the binding path of netlink.

This is used by ctnetlink to allow module autoloading for the case
in which one user executes:

 conntrack -E

So far, this resulted in nfnetlink loaded, but not
nf_conntrack_netlink.

I have received in the past many complains on this behaviour.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29 16:46:06 -07:00
Pablo Neira Ayuso a31f2d17b3 netlink: add netlink_kernel_cfg parameter to netlink_kernel_create
This patch adds the following structure:

struct netlink_kernel_cfg {
        unsigned int    groups;
        void            (*input)(struct sk_buff *skb);
        struct mutex    *cb_mutex;
};

That can be passed to netlink_kernel_create to set optional configurations
for netlink kernel sockets.

I've populated this structure by looking for NULL and zero parameters at the
existing code. The remaining parameters that always need to be set are still
left in the original interface.

That includes optional parameters for the netlink socket creation. This allows
easy extensibility of this interface in the future.

This patch also adapts all callers to use this new interface.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29 16:46:02 -07:00
Neil Horman e9412c3708 genetlink: Build a generic netlink family module alias
Generic netlink searches for -type- formatted aliases when requesting a module to
fulfill a protocol request (i.e. net-pf-16-proto-16-type-<x>, where x is a type
value).  However generic netlink protocols have no well defined type numbers,
they have string names.  Modify genl_ctrl_getfamily to request an alias in the
format net-pf-16-proto-16-family-<x> instead, where x is a generic string, and
add a macro that builds on the previously added MODULE_ALIAS_NET_PF_PROTO_NAME
macro to allow modules to specifify those generic strings.

Note, l2tp previously hacked together an net-pf-16-proto-16-type-l2tp alias
using the MODULE_ALIAS macro, with these updates we can convert that to use the
PROTO_NAME macro.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: James Chapman <jchapman@katalix.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-29 22:33:56 -04:00
Eric Dumazet bfb253c9b2 af_netlink: drop_monitor/dropwatch friendly
Need to consume_skb() instead of kfree_skb() in netlink_dump() and
netlink_unicast_kernel() to avoid false dropwatch positives.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-24 00:35:14 -04:00
Eric Dumazet 658cb354ed af_netlink: cleanups
netlink_destroy_callback() move to avoid forward reference

CodingStyle cleanups

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-24 00:35:14 -04:00
Eric Dumazet 8460c00f6e netlink: dont drop packet but consume it
When we need to clone skb, we dont drop a packet.
Call consume_skb() to not confuse dropwatch.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-19 14:23:55 -04:00
David S. Miller 06eb4eafbd Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-04-10 14:30:45 -04:00
Eric Dumazet 4a7e7c2ad5 netlink: fix races after skb queueing
As soon as an skb is queued into socket receive_queue, another thread
can consume it, so we are not allowed to reference skb anymore, or risk
use after free.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-06 04:21:06 -04:00
David S. Miller 444653f696 genetlink: Stop using NLA_PUT*().
These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-01 18:43:25 -04:00
Pablo Neira Ayuso 7175c88307 netlink: allow to pass data pointer to netlink_dump_start() callback
This patch allows you to pass a data pointer that can be
accessed from the dump callback.

Netfilter is going to use this patch to provide filtered dumps
to user-space. This is specifically interesting in ctnetlink that
may handle lots of conntrack entries. We can save precious
cycles by skipping the conversion to TLV format of conntrack
entries that are not interesting for user-space.

More specifically, ctnetlink will include one operation to allow
to filter the dumping of conntrack entries by ctmark values.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-26 14:10:44 -05:00
Pablo Neira Ayuso 80d326fab5 netlink: add netlink_dump_control structure for netlink_dump_start()
Davem considers that the argument list of this interface is getting
out of control. This patch tries to address this issue following
his proposal:

struct netlink_dump_control c = { .dump = dump, .done = done, ... };

netlink_dump_start(..., &c);

Suggested by David S. Miller.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-26 14:10:06 -05:00
Denys Vlasenko a46621a3a8 net: Deinline __nlmsg_put and genlmsg_put. -7k code on i386 defconfig.
text	   data	    bss	    dec	    hex	filename
8455963	 532732	1810804	10799499 a4c98b	vmlinux.o.before
8448899	 532732	1810804	10792435 a4adf3	vmlinux.o

This change also removes commented-out copy of __nlmsg_put
which was last touched in 2005 with "Enable once all users
have been converted" comment on top.

Changes in v2: rediffed against net-next.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-30 15:22:06 -05:00
Linus Torvalds c49c41a413 Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security
* 'for-linus' of git://selinuxproject.org/~jmorris/linux-security:
  capabilities: remove __cap_full_set definition
  security: remove the security_netlink_recv hook as it is equivalent to capable()
  ptrace: do not audit capability check when outputing /proc/pid/stat
  capabilities: remove task_ns_* functions
  capabitlies: ns_capable can use the cap helpers rather than lsm call
  capabilities: style only - move capable below ns_capable
  capabilites: introduce new has_ns_capabilities_noaudit
  capabilities: call has_ns_capability from has_capability
  capabilities: remove all _real_ interfaces
  capabilities: introduce security_capable_noaudit
  capabilities: reverse arguments to security_capable
  capabilities: remove the task from capable LSM hook entirely
  selinux: sparse fix: fix several warnings in the security server cod
  selinux: sparse fix: fix warnings in netlink code
  selinux: sparse fix: eliminate warnings for selinuxfs
  selinux: sparse fix: declare selinux_disable() in security.h
  selinux: sparse fix: move selinux_complete_init
  selinux: sparse fix: make selinux_secmark_refcount static
  SELinux: Fix RCU deref check warning in sel_netport_insert()

Manually fix up a semantic mis-merge wrt security_netlink_recv():

 - the interface was removed in commit fd77846152 ("security: remove
   the security_netlink_recv hook as it is equivalent to capable()")

 - a new user of it appeared in commit a38f7907b9 ("crypto: Add
   userspace configuration API")

causing no automatic merge conflict, but Eric Paris pointed out the
issue.
2012-01-14 18:36:33 -08:00
Eric Paris fd77846152 security: remove the security_netlink_recv hook as it is equivalent to capable()
Once upon a time netlink was not sync and we had to get the effective
capabilities from the skb that was being received.  Today we instead get
the capabilities from the current task.  This has rendered the entire
purpose of the hook moot as it is now functionally equivalent to the
capable() call.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-05 18:53:01 -05:00
Stephen Hemminger fa84309533 genetlink: add auto module loading
When testing L2TP support, I discovered that the l2tp module is not autoloaded
as are other netlink interfaces. There is because of lack of hook in genetlink to call
request_module and load the module.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-28 13:48:55 -05:00
David S. Miller 035c4c16be netlink: Undo const marker in netlink_is_kernel().
We can't do this without propagating the const to nlk_sk()
too, otherwise:

net/netlink/af_netlink.c: In function ‘netlink_is_kernel’:
net/netlink/af_netlink.c:103:2: warning: passing argument 1 of ‘nlk_sk’ discards ‘const’ qualifier from pointer target type [enabled by default]
net/netlink/af_netlink.c:96:36: note: expected ‘struct sock *’ but argument is of type ‘const struct sock *’

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-23 17:33:03 -05:00
stephen hemminger 2c64580046 netlink: wake up netlink listeners sooner (v2)
This patch changes it to yield sooner at halfway instead. Still not a cure-all
for listener overrun if listner is slow, but works much reliably.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-22 22:37:19 -05:00
stephen hemminger b57ef81ff8 netlink: af_netlink cleanup (v2)
Don't inline functions that cover several lines, and do inline
the trivial ones. Also make some arguments const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-22 22:37:19 -05:00
Pravin B Shelar 86b1309c7e genetlink: Add lockdep_genl_is_held().
Open vSwitch uses genl_mutex locking to protect datapath
data-structures like flow-table, flow-actions. Following patch adds
lockdep_genl_is_held() which is used for rcu annotation to prove
locking.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
2011-12-03 09:35:07 -08:00
Pravin B Shelar 263ba61d3b genetlink: Add genl_notify()
Open vSwitch uses Generic Netlink interface for communication
between userspace and kernel module. genl_notify() is used
for sending notification back to userspace.

genl_notify() is analogous to rtnl_notify() but uses genl_sock
instead of rtnl.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
2011-12-03 09:35:05 -08:00
Eric Dumazet 16e5726269 af_unix: dont send SCM_CREDENTIALS by default
Since commit 7361c36c52 (af_unix: Allow credentials to work across
user and pid namespaces) af_unix performance dropped a lot.

This is because we now take a reference on pid and cred in each write(),
and release them in read(), usually done from another process,
eventually from another cpu. This triggers false sharing.

# Events: 154K cycles
#
# Overhead  Command       Shared Object        Symbol
# ........  .......  ..................  .........................
#
    10.40%  hackbench  [kernel.kallsyms]   [k] put_pid
     8.60%  hackbench  [kernel.kallsyms]   [k] unix_stream_recvmsg
     7.87%  hackbench  [kernel.kallsyms]   [k] unix_stream_sendmsg
     6.11%  hackbench  [kernel.kallsyms]   [k] do_raw_spin_lock
     4.95%  hackbench  [kernel.kallsyms]   [k] unix_scm_to_skb
     4.87%  hackbench  [kernel.kallsyms]   [k] pid_nr_ns
     4.34%  hackbench  [kernel.kallsyms]   [k] cred_to_ucred
     2.39%  hackbench  [kernel.kallsyms]   [k] unix_destruct_scm
     2.24%  hackbench  [kernel.kallsyms]   [k] sub_preempt_count
     1.75%  hackbench  [kernel.kallsyms]   [k] fget_light
     1.51%  hackbench  [kernel.kallsyms]   [k]
__mutex_lock_interruptible_slowpath
     1.42%  hackbench  [kernel.kallsyms]   [k] sock_alloc_send_pskb

This patch includes SCM_CREDENTIALS information in a af_unix message/skb
only if requested by the sender, [man 7 unix for details how to include
ancillary data using sendmsg() system call]

Note: This might break buggy applications that expected SCM_CREDENTIAL
from an unaware write() system call, and receiver not using SO_PASSCRED
socket option.

If SOCK_PASSCRED is set on source or destination socket, we still
include credentials for mere write() syscalls.

Performance boost in hackbench : more than 50% gain on a 16 thread
machine (2 quad-core cpus, 2 threads per core)

hackbench 20 thread 2000

4.228 sec instead of 9.102 sec

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-28 13:29:50 -04:00
Eric Dumazet 33d480ce6d net: cleanup some rcu_dereference_raw
RCU api had been completed and rcu_access_pointer() or
rcu_dereference_protected() are better than generic
rcu_dereference_raw()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-12 02:55:28 -07:00
John W. Linville 36099365c7 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem
Conflicts:
	drivers/net/wireless/rtlwifi/pci.c
	include/linux/netlink.h
2011-06-24 15:25:51 -04:00
Johannes Berg 670dc2833d netlink: advertise incomplete dumps
Consider the following situation:
 * a dump that would show 8 entries, four in the first
   round, and four in the second
 * between the first and second rounds, 6 entries are
   removed
 * now the second round will not show any entry, and
   even if there is a sequence/generation counter the
   application will not know

To solve this problem, add a new flag NLM_F_DUMP_INTR
to the netlink header that indicates the dump wasn't
consistent, this flag can also be set on the MSG_DONE
message that terminates the dump, and as such above
situation can be detected.

To achieve this, add a sequence counter to the netlink
callback struct. Of course, netlink code still needs
to use this new functionality. The correct way to do
that is to always set cb->seq when a dumpit callback
is invoked and call nl_dump_check_consistent() for
each new message. The core code will also call this
function for the final MSG_DONE message.

To make it usable with generic netlink, a new function
genlmsg_nlhdr() is needed to obtain the netlink header
from the genetlink user header.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-06-22 16:09:45 -04:00
Dan Carpenter c63d6ea306 rtnetlink: unlock on error path in netlink_dump()
In c7ac8679be "rtnetlink: Compute and store minimum ifinfo dump
size", we moved the allocation under the lock so we need to unlock
on error path.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@conan.davemloft.net>
2011-06-16 23:51:35 -04:00
Greg Rose c7ac8679be rtnetlink: Compute and store minimum ifinfo dump size
The message size allocated for rtnl ifinfo dumps was limited to
a single page.  This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2011-06-09 20:38:07 -07:00
Dan Rosenberg 71338aa7d0 net: convert %p usage to %pK
The %pK format specifier is designed to hide exposed kernel pointers,
specifically via /proc interfaces.  Exposing these pointers provides an
easy target for kernel write vulnerabilities, since they reveal the
locations of writable structures containing easily triggerable function
pointers.  The behavior of %pK depends on the kptr_restrict sysctl.

If kptr_restrict is set to 0, no deviation from the standard %p behavior
occurs.  If kptr_restrict is set to 1, the default, if the current user
(intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG
(currently in the LSM tree), kernel pointers using %pK are printed as 0's.
 If kptr_restrict is set to 2, kernel pointers using %pK are printed as
0's regardless of privileges.  Replacing with 0's was chosen over the
default "(null)", which cannot be parsed by userland %p, which expects
"(nil)".

The supporting code for kptr_restrict and %pK are currently in the -mm
tree.  This patch converts users of %p in net/ to %pK.  Cases of printing
pointers to the syslog are not covered, since this would eliminate useful
information for postmortem debugging and the reading of the syslog is
already optionally protected by the dmesg_restrict sysctl.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: James Morris <jmorris@namei.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Thomas Graf <tgraf@infradead.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-24 01:13:12 -04:00
Lai Jiangshan 37b6b935e9 net,rcu: convert call_rcu(listeners_free_rcu) to kfree_rcu()
The rcu callback listeners_free_rcu() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(listeners_free_rcu).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-05-07 22:50:51 -07:00
David S. Miller 0a0e9ae1bd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/bnx2x/bnx2x.h
2011-03-03 21:27:42 -08:00
Patrick McHardy 01a16b21d6 netlink: kill eff_cap from struct netlink_skb_parms
Netlink message processing in the kernel is synchronous these days,
capabilities can be checked directly in security_netlink_recv() from
the current process.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Reviewed-by: James Morris <jmorris@namei.org>
[chrisw: update to include pohmelfs and uvesafb]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03 13:32:07 -08:00
Patrick McHardy c53fa1ed92 netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms
Netlink message processing in the kernel is synchronous these days, the
session information can be collected when needed.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03 10:55:40 -08:00
Andrey Vagin b44d211e16 netlink: handle errors from netlink_dump()
netlink_dump() may failed, but nobody handle its error.
It generates output data, when a previous portion has been returned to
user space. This mechanism works when all data isn't go in skb. If we
enter in netlink_recvmsg() and skb is absent in the recv queue, the
netlink_dump() will not been executed. So if netlink_dump() is failed
one time, the new data never appear and the reader will sleep forever.

netlink_dump() is called from two places:

1. from netlink_sendmsg->...->netlink_dump_start().
   In this place we can report error directly and it will be returned
   by sendmsg().

2. from netlink_recvmsg
   There we can't report error directly, because we have a portion of
   valid output data and call netlink_dump() for prepare the next portion.
   If netlink_dump() is failed, the socket will be mark as error and the
   next recvmsg will be failed.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-28 12:18:12 -08:00
David S. Miller b8f3ab4290 Revert "netlink: test for all flags of the NLM_F_DUMP composite"
This reverts commit 0ab03c2b14.

It breaks several things including the avahi daemon.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19 13:34:20 -08:00
Jan Engelhardt 0ab03c2b14 netlink: test for all flags of the NLM_F_DUMP composite
Due to NLM_F_DUMP is composed of two bits, NLM_F_ROOT | NLM_F_MATCH,
when doing "if (x & NLM_F_DUMP)", it tests for _either_ of the bits
being set. Because NLM_F_MATCH's value overlaps with NLM_F_EXCL,
non-dump requests with NLM_F_EXCL set are mistaken as dump requests.

Substitute the condition to test for _all_ bits being set.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-09 16:25:03 -08:00
Eric Dumazet 5c398dc8f5 netlink: fix netlink_change_ngroups()
commit 6c04bb18dd (netlink: use call_rcu for netlink_change_ngroups)
used a somewhat convoluted and racy way to perform call_rcu().

The old block of memory is freed after a grace period, but the rcu_head
used to track it is located in new block.

This can clash if we call two times or more netlink_change_ngroups(),
and a block is freed before another. call_rcu() called on different cpus
makes no guarantee in order of callbacks.

Fix this using a more standard way of handling this : Each block of
memory contains its own rcu_head, so that no 'use after free' can
happens.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Johannes Berg <johannes@sipsolutions.net>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-24 16:25:39 -07:00
John W. Linville e9a68707d7 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem
Conflicts:
	Documentation/feature-removal-schedule.txt
	drivers/net/wireless/ipw2x00/ipw2200.c
2010-10-08 15:39:28 -04:00
Johannes Berg ff4c92d85c genetlink: introduce pre_doit/post_doit hooks
Each family may have some amount of boilerplate
locking code that applies to most, or even all,
commands.

This allows a family to handle such things in
a more generic way, by allowing it to
 a) include private flags in each operation
 b) specify a pre_doit hook that is called,
    before an operation's doit() callback and
    may return an error directly,
 c) specify a post_doit hook that can undo
    locking or similar things done by pre_doit,
    and finally
 d) include two private pointers in each info
    struct passed between all these operations
    including doit(). (It's two because I'll
    need two in nl80211 -- can be extended.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-10-05 13:35:30 -04:00
David S. Miller b963ea89f0 netlink: Make NETLINK_USERSOCK work again.
Once we started enforcing the a nl_table[] entry exist for
a protocol, NETLINK_USERSOCK stopped working.  Add a dummy
table entry so that it works again.

Reported-by: Thomas Voegtle <tv@lio96.de>
Tested-by: Thomas Voegtle <tv@lio96.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-31 09:51:37 -07:00
Johannes Berg 68d6ac6d27 netlink: fix compat recvmsg
Since
commit 1dacc76d00
Author: Johannes Berg <johannes@sipsolutions.net>
Date:   Wed Jul 1 11:26:02 2009 +0000

    net/compat/wext: send different messages to compat tasks

we had a race condition when setting and then
restoring frag_list. Eric attempted to fix it,
but the fix created even worse problems.

However, the original motivation I had when I
added the code that turned out to be racy is
no longer clear to me, since we only copy up
to skb->len to userspace, which doesn't include
the frag_list length. As a result, not doing
any frag_list clearing and restoring avoids
the race condition, while not introducing any
other problems.

Additionally, while preparing this patch I found
that since none of the remaining netlink code is
really aware of the frag_list, we need to use the
original skb's information for packet information
and credentials. This fixes, for example, the
group information received by compat tasks.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@kernel.org [2.6.31+, for 2.6.35 revert 1235f504aa]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-18 23:35:58 -07:00
David S. Miller daa3766e70 Revert "netlink: netlink_recvmsg() fix"
This reverts commit 1235f504aa.

It causes regressions worse than the problem it was trying
to fix.  Eric will try to solve the problem another way.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-15 23:21:50 -07:00
Changli Gao 652c671746 genetlink: use genl_register_family_with_ops()
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-26 21:00:10 -07:00
Changli Gao 416c2f9cf5 genetlink: cleanup code according to CodingStyle
If the function is exported, the EXPORT* macro for it should follow immediately
after the closing function brace line.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
----
 net/netlink/genetlink.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-26 20:53:49 -07:00
Eric Dumazet 1235f504aa netlink: netlink_recvmsg() fix
commit 1dacc76d00
(net/compat/wext: send different messages to compat tasks)
introduced a race condition on netlink, in case MSG_PEEK is used.

An skb given by skb_recv_datagram() might be shared, we must copy it
before any modification, or risk fatal corruption.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-26 13:09:16 -07:00
Neil Horman 70d4bf6d46 drop_monitor: convert some kfree_skb call sites to consume_skb
Convert a few calls from kfree_skb to consume_skb

Noticed while I was working on dropwatch that I was detecting lots of internal
skb drops in several places.  While some are legitimate, several were not,
freeing skbs that were at the end of their life, rather than being discarded due
to an error.  This patch converts those calls sites from using kfree_skb to
consume_skb, which quiets the in-kernel drop_monitor code from detecting them as
drops.  Tested successfully by myself

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-20 13:28:05 -07:00
Eric W. Biederman b47030c71d af_netlink: Add needed scm_destroy after scm_send.
scm_send occasionally allocates state in the scm_cookie, so I have
modified netlink_sendmsg to guarantee that when scm_send succeeds
scm_destory will be called to free that state.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16 14:55:56 -07:00
Eric W. Biederman 910a7e905f netlink: Implment netlink_broadcast_filtered
When netlink sockets are used to convey data that is in a namespace
we need a way to select a subset of the listening sockets to deliver
the packet to.  For the network namespace we have been doing this
by only transmitting packets in the correct network namespace.

For data belonging to other namespaces netlink_bradcast_filtered
provides a mechanism that allows us to examine the destination
socket and to decide if we should transmit the specified packet
to it.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:32 -07:00