Commit Graph

134 Commits

Author SHA1 Message Date
Florian Westphal 1b0890cd60 netfilter: nfnetlink: avoid deadlock due to synchronous request_module
Thomas and Juliana report a deadlock when running:

(rmmod nf_conntrack_netlink/xfrm_user)

  conntrack -e NEW -E &
  modprobe -v xfrm_user

They provided following analysis:

conntrack -e NEW -E
    netlink_bind()
        netlink_lock_table() -> increases "nl_table_users"
            nfnetlink_bind()
            # does not unlock the table as it's locked by netlink_bind()
                __request_module()
                    call_usermodehelper_exec()

This triggers "modprobe nf_conntrack_netlink" from kernel, netlink_bind()
won't return until modprobe process is done.

"modprobe xfrm_user":
    xfrm_user_init()
        register_pernet_subsys()
            -> grab pernet_ops_rwsem
                ..
                netlink_table_grab()
                    calls schedule() as "nl_table_users" is non-zero

so modprobe is blocked because netlink_bind() increased
nl_table_users while also holding pernet_ops_rwsem.

"modprobe nf_conntrack_netlink" runs and inits nf_conntrack_netlink:
    ctnetlink_init()
        register_pernet_subsys()
            -> blocks on "pernet_ops_rwsem" thanks to xfrm_user module

both modprobe processes wait on one another -- neither can make
progress.

Switch netlink_bind() to "nowait" modprobe -- this releases the netlink
table lock, which then allows both modprobe instances to complete.

Reported-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Reported-by: Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-07-15 07:56:58 +02:00
Johannes Berg 8cb081746c netlink: make validation more configurable for future strictness
We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type >= max) & NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs > max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -> nla_parse_deprecated
 * nla_parse_strict    -> nla_parse_deprecated_strict
 * nlmsg_parse         -> nlmsg_parse_deprecated
 * nlmsg_parse_strict  -> nlmsg_parse_deprecated_strict
 * nla_parse_nested    -> nla_parse_nested_deprecated
 * nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:07:21 -04:00
Florian Westphal f102d66b33 netfilter: nf_tables: use dedicated mutex to guard transactions
Continue to use nftnl subsys mutex to protect (un)registration of hook types,
expressions and so on, but force batch operations to do their own
locking.

This allows distinct net namespaces to perform transactions in parallel.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-18 11:26:48 +02:00
Florian Westphal be2ab5b4d5 netfilter: nf_tables: take module reference when starting a batch
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-18 11:26:46 +02:00
Florian Westphal ca2f18be79 netfilter: nf_tables: make valid_genid callback mandatory
always call this function, followup patch can use this to
aquire a per-netns transaction log to guard the entire batch
instead of using the nfnl susbsys mutex (which is shared among all
namespaces).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-18 11:26:45 +02:00
Florian Westphal 71ad00c50d netfilter: nf_tables: fix module unload race
We must first remove the nfnetlink protocol handler when nf_tables module
is unloaded -- we don't want userspace to submit new change requests once
we've started to tear down nft state.

Furthermore, nfnetlink must not call any subsystem function after
call_batch returned -EAGAIN.

EAGAIN means the subsys mutex was dropped, so its unlikely but possible that
nf_tables subsystem was removed due to 'rmmod nf_tables' on another cpu.

Therefore, we must abort batch completely and not move on to next part of
the batch.

Last, we can't invoke ->abort unless we've checked that the subsystem is
still registered.

Change netns exit path of nf_tables to make sure any incompleted
transaction gets removed on exit.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-06-12 19:28:18 +02:00
Kees Cook 7b7744e2aa netfilter: nfnetlink: Remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this
allocates the maximum size expected for all possible attrs and adds
sanity-checks at both registration and usage to make sure nothing
gets out of sync.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-06-01 09:47:42 +02:00
Pablo Neira Ayuso a654de8fdc netfilter: nf_tables: fix chain dependency validation
The following ruleset:

 add table ip filter
 add chain ip filter input { type filter hook input priority 4; }
 add chain ip filter ap
 add rule ip filter input jump ap
 add rule ip filter ap masquerade

results in a panic, because the masquerade extension should be rejected
from the filter chain. The existing validation is missing a chain
dependency check when the rule is added to the non-base chain.

This patch fixes the problem by walking down the rules from the
basechains, searching for either immediate or lookup expressions, then
jumping to non-base chains and again walking down the rules to perform
the expression validation, so we make sure the full ruleset graph is
validated. This is done only once from the commit phase, in case of
problem, we abort the transaction and perform fine grain validation for
error reporting. This patch requires 003087911a ("netfilter:
nfnetlink: allow commit to fail") to achieve this behaviour.

This patch also adds a cleanup callback to nfnl batch interface to reset
the validate state from the exit path.

As a result of this patch, nf_tables_check_loops() doesn't use
->validate to check for loops, instead it just checks for immediate
expressions.

Reported-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-06-01 09:46:22 +02:00
Florian Westphal 8a3d4c3612 netfilter: nf_tables: fail batch if fatal signal is pending
abort batch processing and return so task can exit faster.
Otherwise even SIGKILL has no immediate effect.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-05-29 14:50:28 +02:00
Florian Westphal 003087911a netfilter: nfnetlink: allow commit to fail
->commit() cannot fail at the moment.

Followup-patch adds kmalloc calls in the commit phase, so we'll need
to be able to handle errors.

Make it so that -EGAIN causes a full replay, and make other errors
cause the transaction to fail.

Failing is ok from a consistency point of view as long as we
perform all actions that could return an error before
we increment the generation counter and the base seq.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-05-29 00:27:26 +02:00
Pablo Neira Ayuso e553116652 netfilter: remove messages print and boot/module load time
Several reasons for this:

* Several modules maintain internal version numbers, that they print at
  boot/module load time, that are not exposed to userspace, as a
  primitive mechanism to make revision number control from the earlier
  days of Netfilter.

* IPset shows the protocol version at boot/module load time, instead
  display this via module description, as Jozsef suggested.

* Remove copyright notice at boot/module load time in two spots, the
  Netfilter codebase is a collective development effort, if we would
  have to display copyrights for each contributor at boot/module load
  time for each extensions we have, we would probably fill up logs with
  lots of useless information - from a technical standpoint.

So let's be consistent and remove them all.

Acked-by: Florian Westphal <fw@strlen.de>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-19 18:39:49 +01:00
Mateusz Jurczyk f55ce7b024 netfilter: nfnetlink: Improve input length sanitization in nfnetlink_rcv
Verify that the length of the socket buffer is sufficient to cover the
nlmsghdr structure before accessing the nlh->nlmsg_len field for further
input sanitization. If the client only supplies 1-3 bytes of data in
sk_buff, then nlh->nlmsg_len remains partially uninitialized and
contains leftover memory from the corresponding kernel allocation.
Operating on such data may result in indeterminate evaluation of the
nlmsg_len < NLMSG_HDRLEN expression.

The bug was discovered by a runtime instrumentation designed to detect
use of uninitialized memory in the kernel. The patch prevents this and
other similar tools (e.g. KMSAN) from flagging this behavior in the future.

Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-17 13:27:46 +02:00
Pablo Neira Ayuso 04ba724b65 netfilter: nfnetlink: extended ACK reporting
Pass down struct netlink_ext_ack as parameter to all of our nfnetlink
subsystem callbacks, so we can work on follow up patches to provide
finer grain error reporting using the new infrastructure that
2d4bc93368 ("netlink: extended ACK reporting") provides.

No functional change, just pass down this new object to callbacks.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-06-19 19:38:24 +02:00
David S. Miller a01aa920b8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter updates for your net-next
tree. A large bunch of code cleanups, simplify the conntrack extension
codebase, get rid of the fake conntrack object, speed up netns by
selective synchronize_net() calls. More specifically, they are:

1) Check for ct->status bit instead of using nfct_nat() from IPVS and
   Netfilter codebase, patch from Florian Westphal.

2) Use kcalloc() wherever possible in the IPVS code, from Varsha Rao.

3) Simplify FTP IPVS helper module registration path, from Arushi Singhal.

4) Introduce nft_is_base_chain() helper function.

5) Enforce expectation limit from userspace conntrack helper,
   from Gao Feng.

6) Add nf_ct_remove_expect() helper function, from Gao Feng.

7) NAT mangle helper function return boolean, from Gao Feng.

8) ctnetlink_alloc_expect() should only work for conntrack with
   helpers, from Gao Feng.

9) Add nfnl_msg_type() helper function to nfnetlink to build the
   netlink message type.

10) Get rid of unnecessary cast on void, from simran singhal.

11) Use seq_puts()/seq_putc() instead of seq_printf() where possible,
    also from simran singhal.

12) Use list_prev_entry() from nf_tables, from simran signhal.

13) Remove unnecessary & on pointer function in the Netfilter and IPVS
    code.

14) Remove obsolete comment on set of rules per CPU in ip6_tables,
    no longer true. From Arushi Singhal.

15) Remove duplicated nf_conntrack_l4proto_udplite4, from Gao Feng.

16) Remove unnecessary nested rcu_read_lock() in
    __nf_nat_decode_session(). Code running from hooks are already
    guaranteed to run under RCU read side.

17) Remove deadcode in nf_tables_getobj(), from Aaron Conole.

18) Remove double assignment in nf_ct_l4proto_pernet_unregister_one(),
    also from Aaron.

19) Get rid of unsed __ip_set_get_netlink(), from Aaron Conole.

20) Don't propagate NF_DROP error to userspace via ctnetlink in
    __nf_nat_alloc_null_binding() function, from Gao Feng.

21) Revisit nf_ct_deliver_cached_events() to remove unnecessary checks,
    from Gao Feng.

22) Kill the fake untracked conntrack objects, use ctinfo instead to
    annotate a conntrack object is untracked, from Florian Westphal.

23) Remove nf_ct_is_untracked(), now obsolete since we have no
    conntrack template anymore, from Florian.

24) Add event mask support to nft_ct, also from Florian.

25) Move nf_conn_help structure to
    include/net/netfilter/nf_conntrack_helper.h.

26) Add a fixed 32 bytes scratchpad area for conntrack helpers.
    Thus, we don't deal with variable conntrack extensions anymore.
    Make sure userspace conntrack helper doesn't go over that size.
    Remove variable size ct extension infrastructure now this code
    got no more clients. From Florian Westphal.

27) Restore offset and length of nf_ct_ext structure to 8 bytes now
    that wraparound is not possible any longer, also from Florian.

28) Allow to get rid of unassured flows under stress in conntrack,
    this applies to DCCP, SCTP and TCP protocols, from Florian.

29) Shrink size of nf_conntrack_ecache structure, from Florian.

30) Use TCP_MAX_WSCALE instead of hardcoded 14 in TCP tracker,
    from Gao Feng.

31) Register SYNPROXY hooks on demand, from Florian Westphal.

32) Use pernet hook whenever possible, instead of global hook
    registration, from Florian Westphal.

33) Pass hook structure to ebt_register_table() to consolidate some
    infrastructure code, from Florian Westphal.

34) Use consume_skb() and return NF_STOLEN, instead of NF_DROP in the
    SYNPROXY code, to make sure device stats are not fooled, patch
    from Gao Feng.

35) Remove NF_CT_EXT_F_PREALLOC this kills quite some code that we
    don't need anymore if we just select a fixed size instead of
    expensive runtime time calculation of this. From Florian.

36) Constify nf_ct_extend_register() and nf_ct_extend_unregister(),
    from Florian.

37) Simplify nf_ct_ext_add(), this kills nf_ct_ext_create(), from
    Florian.

38) Attach NAT extension on-demand from masquerade and pptp helper
    path, from Florian.

39) Get rid of useless ip_vs_set_state_timeout(), from Aaron Conole.

40) Speed up netns by selective calls of synchronize_net(), from
    Florian Westphal.

41) Silence stack size warning gcc in 32-bit arch in snmp helper,
    from Florian.

42) Inconditionally call nf_ct_ext_destroy(), even if we have no
    extensions, to deal with the NF_NAT_MANIP_SRC case. Patch from
    Liping Zhang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-01 10:47:53 -04:00
Johannes Berg fe52145f91 netlink: pass extended ACK struct where available
This is an add-on to the previous patch that passes the extended ACK
structure where it's already available by existing genl_info or extack
function arguments.

This was done with this spatch (with some manual adjustment of
indentation):

@@
expression A, B, C, D, E;
identifier fn, info;
@@
fn(..., struct genl_info *info, ...) {
...
-nlmsg_parse(A, B, C, D, E, NULL)
+nlmsg_parse(A, B, C, D, E, info->extack)
...
}

@@
expression A, B, C, D, E;
identifier fn, info;
@@
fn(..., struct genl_info *info, ...) {
<...
-nla_parse_nested(A, B, C, D, NULL)
+nla_parse_nested(A, B, C, D, info->extack)
...>
}

@@
expression A, B, C, D, E;
identifier fn, extack;
@@
fn(..., struct netlink_ext_ack *extack, ...) {
<...
-nlmsg_parse(A, B, C, D, E, NULL)
+nlmsg_parse(A, B, C, D, E, extack)
...>
}

@@
expression A, B, C, D, E;
identifier fn, extack;
@@
fn(..., struct netlink_ext_ack *extack, ...) {
<...
-nla_parse(A, B, C, D, E, NULL)
+nla_parse(A, B, C, D, E, extack)
...>
}

@@
expression A, B, C, D, E;
identifier fn, extack;
@@
fn(..., struct netlink_ext_ack *extack, ...) {
...
-nlmsg_parse(A, B, C, D, E, NULL)
+nlmsg_parse(A, B, C, D, E, extack)
...
}

@@
expression A, B, C, D;
identifier fn, extack;
@@
fn(..., struct netlink_ext_ack *extack, ...) {
<...
-nla_parse_nested(A, B, C, D, NULL)
+nla_parse_nested(A, B, C, D, extack)
...>
}

@@
expression A, B, C, D;
identifier fn, extack;
@@
fn(..., struct netlink_ext_ack *extack, ...) {
<...
-nlmsg_validate(A, B, C, D, NULL)
+nlmsg_validate(A, B, C, D, extack)
...>
}

@@
expression A, B, C, D;
identifier fn, extack;
@@
fn(..., struct netlink_ext_ack *extack, ...) {
<...
-nla_validate(A, B, C, D, NULL)
+nla_validate(A, B, C, D, extack)
...>
}

@@
expression A, B, C;
identifier fn, extack;
@@
fn(..., struct netlink_ext_ack *extack, ...) {
<...
-nla_validate_nested(A, B, C, NULL)
+nla_validate_nested(A, B, C, extack)
...>
}

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:22 -04:00
Johannes Berg fceb6435e8 netlink: pass extended ACK struct to parsing functions
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:22 -04:00
Johannes Berg 2d4bc93368 netlink: extended ACK reporting
Add the base infrastructure and UAPI for netlink extended ACK
reporting. All "manual" calls to netlink_ack() pass NULL for now and
thus don't get extended ACK reporting.

Big thanks goes to Pablo Neira Ayuso for not only bringing up the
whole topic at netconf (again) but also coming up with the nlattr
passing trick and various other ideas.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:20 -04:00
Arushi Singhal d4ef383541 netfilter: Remove exceptional & on function name
Remove & from function pointers to conform to the style found elsewhere
in the file. Done using the following semantic patch

// <smpl>
@r@
identifier f;
@@

f(...) { ... }
@@
identifier r.f;
@@

- &f
+ f
// </smpl>

Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-07 18:24:47 +02:00
David S. Miller ccaba0621a Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Revisit warning logic when not applying default helper assignment.
   Jiri Kosina considers we are breaking existing setups and not warning
   our users accordinly now that automatic helper assignment has been
   turned off by default. So let's make him happy by spotting the warning
   by when we find a helper but we cannot attach, instead of warning on the
   former deprecated behaviour. Patch from Jiri Kosina.

2) Two patches to fix regression in ctnetlink interfaces with
   nfnetlink_queue. Specifically, perform more relaxed in CTA_STATUS
   and do not bail out if CTA_HELP indicates the same helper that we
   already have. Patches from Kevin Cernekee.

3) A couple of bugfixes for ipset via Jozsef Kadlecsik. Due to wrong
   index logic in hash set types and null pointer exception in the
   list:set type.

4) hashlimit bails out with correct userspace parameters due to wrong
   arithmetics in the code that avoids "divide by zero" when
   transforming the userspace timing in milliseconds to token credits.
   Patch from Alban Browaeys.

5) Fix incorrect NFQA_VLAN_MAX definition, patch from
   Ken-ichirou MATSUZAWA.

6) Don't not declare nfnetlink batch error list as static, since this
   may be used by several subsystems at the same time. Patch from
   Liping Zhang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-23 10:59:15 -05:00
Liping Zhang 4eba8b78e1 netfilter: nfnetlink: remove static declaration from err_list
Otherwise, different subsys will race to access the err_list, with holding
the different nfnl_lock(subsys_id).

But this will not happen now, since ->call_batch is only implemented by
nftables, so the err_list is protected by nfnl_lock(NFNL_SUBSYS_NFTABLES).

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-21 13:45:47 +01:00
Pablo Neira Ayuso 8c4d4e8b56 netfilter: nfnetlink: allow to check for generation ID
This patch allows userspace to specify the generation ID that has been
used to build an incremental batch update.

If userspace specifies the generation ID in the batch message as
attribute, then nfnetlink compares it to the current generation ID so
you make sure that you work against the right baseline. Otherwise, bail
out with ERESTART so userspace knows that its changeset is stale and
needs to respin. Userspace can do this transparently at the cost of
taking slightly more time to refresh caches and rework the changeset.

This check is optional, if there is no NFNL_BATCH_GENID attribute in the
batch begin message, then no check is performed.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-12 14:45:11 +01:00
Pablo Neira Ayuso 48656835c0 netfilter: nfnetlink: add nfnetlink_rcv_skb_batch()
Add new nfnetlink_rcv_skb_batch() to wrap initial nfnetlink batch
handling.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-12 14:45:10 +01:00
Pablo Neira Ayuso b745d0358d netfilter: nfnetlink: get rid of u_intX_t types
Use uX types instead.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-12 14:45:09 +01:00
Linus Torvalds 7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
David S. Miller b633353115 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/phy/bcm7xxx.c
	drivers/net/phy/marvell.c
	drivers/net/vxlan.c

All three conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23 00:09:14 -05:00
Florian Westphal 905f0a739a nfnetlink: remove nfnetlink_alloc_skb
Following mmapped netlink removal this code can be simplified by
removing the alloc wrapper.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18 11:42:19 -05:00
Phil Turnbull c58d6c9368 netfilter: nfnetlink: correctly validate length of batch messages
If nlh->nlmsg_len is zero then an infinite loop is triggered because
'skb_pull(skb, msglen);' pulls zero bytes.

The calculation in nlmsg_len() underflows if 'nlh->nlmsg_len <
NLMSG_HDRLEN' which bypasses the length validation and will later
trigger an out-of-bound read.

If the length validation does fail then the malformed batch message is
copied back to userspace. However, we cannot do this because the
nlh->nlmsg_len can be invalid. This leads to an out-of-bounds read in
netlink_ack:

    [   41.455421] ==================================================================
    [   41.456431] BUG: KASAN: slab-out-of-bounds in memcpy+0x1d/0x40 at addr ffff880119e79340
    [   41.456431] Read of size 4294967280 by task a.out/987
    [   41.456431] =============================================================================
    [   41.456431] BUG kmalloc-512 (Not tainted): kasan: bad access detected
    [   41.456431] -----------------------------------------------------------------------------
    ...
    [   41.456431] Bytes b4 ffff880119e79310: 00 00 00 00 d5 03 00 00 b0 fb fe ff 00 00 00 00  ................
    [   41.456431] Object ffff880119e79320: 20 00 00 00 10 00 05 00 00 00 00 00 00 00 00 00   ...............
    [   41.456431] Object ffff880119e79330: 14 00 0a 00 01 03 fc 40 45 56 11 22 33 10 00 05  .......@EV."3...
    [   41.456431] Object ffff880119e79340: f0 ff ff ff 88 99 aa bb 00 14 00 0a 00 06 fe fb  ................
                                            ^^ start of batch nlmsg with
                                               nlmsg_len=4294967280
    ...
    [   41.456431] Memory state around the buggy address:
    [   41.456431]  ffff880119e79400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    [   41.456431]  ffff880119e79480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    [   41.456431] >ffff880119e79500: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
    [   41.456431]                                ^
    [   41.456431]  ffff880119e79580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
    [   41.456431]  ffff880119e79600: fc fc fc fc fc fc fc fc fc fc fb fb fb fb fb fb
    [   41.456431] ==================================================================

Fix this with better validation of nlh->nlmsg_len and by setting
NFNL_BATCH_FAILURE if any batch message fails length validation.

CAP_NET_ADMIN is required to trigger the bugs.

Fixes: 9ea2aa8b7d ("netfilter: nfnetlink: validate nfnetlink header from batch")
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-08 12:56:54 +01:00
Pablo Neira Ayuso 7c7bdf3599 netfilter: nfnetlink: use original skbuff when acking batches
Since bd678e09dc ("netfilter: nfnetlink: fix splat due to incorrect
socket memory accounting in skbuff clones"), we don't manually attach
the sk to the skbuff clone anymore, so we have to use the original
skbuff from netlink_ack() which needs to access the sk pointer.

Fixes: bd678e09dc ("netfilter: nfnetlink: fix splat due to incorrect socket memory accounting in skbuff clones")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-01 00:15:27 +01:00
Pablo Neira Ayuso 5913beaf0d netfilter: nfnetlink: pass down netns pointer to commit() and abort() callbacks
Adapt callsites to avoid recurrent lookup of the netns pointer.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-28 18:43:15 +01:00
Pablo Neira Ayuso 7b8002a151 netfilter: nfnetlink: pass down netns pointer to call() and call_rcu()
Adapt callsites to avoid recurrent lookup of the netns pointer.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-28 18:41:41 +01:00
David S. Miller 59ce9670ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains the first batch of Netfilter updates for
the upcoming 4.5 kernel. This batch contains userspace netfilter header
compilation fixes, support for packet mangling in nf_tables, the new
tracing infrastructure for nf_tables and cgroup2 support for iptables.
More specifically, they are:

1) Two patches to include dependencies in our netfilter userspace
   headers to resolve compilation problems, from Mikko Rapeli.

2) Four comestic cleanup patches for the ebtables codebase, from Ian Morris.

3) Remove duplicate include in the netfilter reject infrastructure,
   from Stephen Hemminger.

4) Two patches to simplify the netfilter defragmentation code for IPv6,
   patch from Florian Westphal.

5) Fix root ownership of /proc/net netfilter for unpriviledged net
   namespaces, from Philip Whineray.

6) Get rid of unused fields in struct nft_pktinfo, from Florian Westphal.

7) Add mangling support to our nf_tables payload expression, from
   Patrick McHardy.

8) Introduce a new netlink-based tracing infrastructure for nf_tables,
   from Florian Westphal.

9) Change setter functions in nfnetlink_log to be void, from
    Rami Rosen.

10) Add netns support to the cttimeout infrastructure.

11) Add cgroup2 support to iptables, from Tejun Heo.

12) Introduce nfnl_dereference_protected() in nfnetlink, from Florian.

13) Add support for mangling pkttype in the nf_tables meta expression,
    also from Florian.

BTW, I need that you pull net into net-next, I have another batch that
requires changes that I don't yet see in net.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-18 15:37:42 -05:00
Florian Westphal 9c55d3b545 nfnetlink: add nfnl_dereference_protected helper
to avoid overly long line in followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-15 15:14:04 +01:00
Pablo Neira Ayuso bd678e09dc netfilter: nfnetlink: fix splat due to incorrect socket memory accounting in skbuff clones
If we attach the sk to the skb from nfnetlink_rcv_batch(), then
netlink_skb_destructor() will underflow the socket receive memory
counter and we get warning splat when releasing the socket.

$ cat /proc/net/netlink
sk       Eth Pid    Groups   Rmem     Wmem     Dump     Locks     Drops     Inode
ffff8800ca903000 12  0      00000000 -54144   0        0 2        0        17942
                                     ^^^^^^

Rmem above shows an underflow.

And here below the warning splat:

[ 1363.815976] WARNING: CPU: 2 PID: 1356 at net/netlink/af_netlink.c:958 netlink_sock_destruct+0x80/0xb9()
[...]
[ 1363.816152] CPU: 2 PID: 1356 Comm: kworker/u16:1 Tainted: G        W       4.4.0-rc1+ #153
[ 1363.816155] Hardware name: LENOVO 23259H1/23259H1, BIOS G2ET32WW (1.12 ) 05/30/2012
[ 1363.816160] Workqueue: netns cleanup_net
[ 1363.816163]  0000000000000000 ffff880119203dd0 ffffffff81240204 0000000000000000
[ 1363.816169]  ffff880119203e08 ffffffff8104db4b ffffffff813d49a1 ffff8800ca771000
[ 1363.816174]  ffffffff81a42b00 0000000000000000 ffff8800c0afe1e0 ffff880119203e18
[ 1363.816179] Call Trace:
[ 1363.816181]  <IRQ>  [<ffffffff81240204>] dump_stack+0x4e/0x79
[ 1363.816193]  [<ffffffff8104db4b>] warn_slowpath_common+0x9a/0xb3
[ 1363.816197]  [<ffffffff813d49a1>] ? netlink_sock_destruct+0x80/0xb9

skb->sk was only needed to lookup for the netns, however we don't need
this anymore since 633c9a840d ("netfilter: nfnetlink: avoid recurrent
netns lookups in call_batch") so this patch removes this manual socket
assignment to resolve this problem.

Reported-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Tested-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
2015-12-10 18:16:29 +01:00
Pablo Neira Ayuso 633c9a840d netfilter: nfnetlink: avoid recurrent netns lookups in call_batch
Pass the net pointer to the call_batch callback functions so we can skip
recurrent lookups.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Tested-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
2015-12-10 13:49:24 +01:00
Florian Westphal 33d5a7b14b netfilter: nf_tables: extend tracing infrastructure
nft monitor mode can then decode and display this trace data.

Parts of LL/Network/Transport headers are provided as separate
attributes.

Otherwise, printing IP address data becomes virtually impossible
for userspace since in the case of the netdev family we really don't
want userspace to have to know all the possible link layer types
and/or sizes just to display/print an ip address.

We also don't want userspace to have to follow ipv6 header chains
to get the s/dport info, the kernel already did this work for us.

To avoid bloating nft_do_chain all data required for tracing is
encapsulated in nft_traceinfo.

The structure is initialized unconditionally(!) for each nft_do_chain
invocation.

This unconditionall call will be moved under a static key in a
followup patch.

With lots of help from Patrick McHardy and Pablo Neira.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-09 13:18:37 +01:00
David S. Miller d9c7dbc11a Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Conflicts:
	net/netfilter/xt_TEE.c

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Fix crash when TEE target is used with no --oif, from Eric Dumazet.

2) Oneliner to fix a crash on the redirect traffic to localhost
   infrastructure when interface has not yet an address, from
   Munehisa Kamata.

3) Oneliner not to request module all the time from nfnetlink due to
   wrong type value, from Florian Westphal.

I'll make sure these patches 1 and 2 hit -stable.
====================

The conflict in net/netfilter/xt_TEE.c was minor, a change
to the 'oif' selection overlapping a function signature
change for the nf_dup_ipv{4,6}() routines.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-04 20:47:50 -05:00
Florian Westphal dbc3617f4c netfilter: nfnetlink: don't probe module if it exists
nfnetlink_bind request_module()s all the time as nfnetlink_get_subsys()
shifts the argument by 8 to obtain the subsys id.

So using type instead of type << 8 always returns NULL.

Fixes: 03292745b0 ("netlink: add nlk->netlink_bind hook for module auto-loading")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-28 03:40:50 +01:00
Yaowei Bai 875e082949 net/nfnetlink: lockdep_nfnl_is_held can be boolean
This patch makes lockdep_nfnl_is_held return bool to improve
readability due to this particular function only using either
one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-09 07:49:00 -07:00
Pablo Neira Ayuso a9de9777d6 netfilter: nfnetlink: work around wrong endianess in res_id field
The convention in nfnetlink is to use network byte order in every header field
as well as in the attribute payload. The initial version of the batching
infrastructure assumes that res_id comes in host byte order though.

The only client of the batching infrastructure is nf_tables, so let's add a
workaround to address this inconsistency. We currently have 11 nfnetlink
subsystems according to NFNL_SUBSYS_COUNT, so we can assume that the subsystem
2560, ie. htons(10), will not be allocated anytime soon, so it can be an alias
of nf_tables from the nfnetlink batching path when interpreting the res_id
field.

Based on original patch from Florian Westphal.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-29 01:02:35 +02:00
Pablo Neira Ayuso 6742b9e310 netfilter: nfnetlink: keep going batch handling on missing modules
After a fresh boot with no modules in place at all and a large rulesets, the
existing nfnetlink_rcv_batch() funcion can take long time to commit the ruleset
due to the many abort path. This is specifically a problem for the existing
client of this code, ie. nf_tables, since it results in several
synchronize_rcu() call in a row.

This patch changes the policy to keep full batch processing on missing modules
errors so we abort only once.

Reported-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-02 17:59:33 +02:00
David S. Miller 4e7a84b1a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
netfilter updates for net-next

The following patchset contains netfilter updates for net-next, just a
bunch of cleanups and small enhancement to selectively flush conntracks
in ctnetlink, more specifically the patches are:

1) Rise default number of buckets in conntrack from 16384 to 65536 in
   systems with >= 4GBytes, patch from Marcelo Leitner.

2) Small refactor to save one level on indentation in xt_osf, from
   Joe Perches.

3) Remove unnecessary sizeof(char) in nf_log, from Fabian Frederick.

4) Another small cleanup to remove redundant variable in nfnetlink,
   from Duan Jiong.

5) Fix compilation warning in nfnetlink_cthelper on parisc, from
   Chen Gang.

6) Fix wrong format in debugging for ctseqadj, from Gao feng.

7) Selective conntrack flushing through the mark for ctnetlink, patch
   from Kristian Evensen.

8) Remove nf_ct_conntrack_flush_report() exported symbol now that is
   not required anymore after the selective flushing patch, again from
   Kristian.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-15 01:50:25 -05:00
David S. Miller 2bd8221804 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
netfilter/ipvs fixes for net

The following patchset contains netfilter/ipvs fixes, they are:

1) Small fix for the FTP helper in IPVS, a diff variable may be left
   unset when CONFIG_IP_VS_IPV6 is set. Patch from Dan Carpenter.

2) Fix nf_tables port NAT in little endian archs, patch from leroy
   christophe.

3) Fix race condition between conntrack confirmation and flush from
   userspace. This is the second reincarnation to resolve this problem.

4) Make sure inner messages in the batch come with the nfnetlink header.

5) Relax strict check from nfnetlink_bind() that may break old userspace
   applications using all 1s group mask.

6) Schedule removal of chains once no sets and rules refer to them in
   the new nf_tables ruleset flush command. Reported by Asbjoern Sloth
   Toennesen.

Note that this batch comes later than usual because of the short
winter holidays.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12 00:14:49 -05:00
Pablo Neira Ayuso 62924af247 netfilter: nfnetlink: relax strict multicast group check from netlink_bind
Relax the checking that was introduced in 97840cb ("netfilter:
nfnetlink: fix insufficient validation in nfnetlink_bind") when the
subscription bitmask is used. Existing userspace code code may request
to listen to all of the existing netlink groups by setting an all to one
subscription group bitmask. Netlink already validates subscription via
setsockopt() for us.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-01-06 22:27:47 +01:00
Pablo Neira Ayuso 9ea2aa8b7d netfilter: nfnetlink: validate nfnetlink header from batch
Make sure there is enough room for the nfnetlink header in the
netlink messages that are part of the batch. There is a similar
check in netlink_rcv_skb().

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-01-06 22:27:46 +01:00
Duan Jiong 0f8162326f netfilter: nfnetlink: remove redundant variable nskb
Actually after netlink_skb_clone() is called, the nskb and
skb will point to the same thing, but they are used just like
they are different, sometimes this is confusing, so i think
there is no necessary to keep nskb anymore.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@soleta.eu>
2015-01-05 12:10:49 +01:00
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
Pablo Neira Ayuso 97840cb67f netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind
Make sure the netlink group exists, otherwise you can trigger an out
of bound array memory access from the netlink_bind() path. This splat
can only be triggered only by superuser.

[  180.203600] UBSan: Undefined behaviour in ../net/netfilter/nfnetlink.c:467:28
[  180.204249] index 9 is out of range for type 'int [9]'
[  180.204697] CPU: 0 PID: 1771 Comm: trinity-main Not tainted 3.18.0-rc4-mm1+ #122
[  180.205365] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org
+04/01/2014
[  180.206498]  0000000000000018 0000000000000000 0000000000000009 ffff88007bdf7da8
[  180.207220]  ffffffff82b0ef5f 0000000000000092 ffffffff845ae2e0 ffff88007bdf7db8
[  180.207887]  ffffffff8199e489 ffff88007bdf7e18 ffffffff8199ea22 0000003900000000
[  180.208639] Call Trace:
[  180.208857] dump_stack (lib/dump_stack.c:52)
[  180.209370] ubsan_epilogue (lib/ubsan.c:174)
[  180.209849] __ubsan_handle_out_of_bounds (lib/ubsan.c:400)
[  180.210512] nfnetlink_bind (net/netfilter/nfnetlink.c:467)
[  180.210986] netlink_bind (net/netlink/af_netlink.c:1483)
[  180.211495] SYSC_bind (net/socket.c:1541)

Moreover, define the missing nf_tables and nf_acct multicast groups too.

Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-11-17 12:01:13 +01:00
David S. Miller 739e4a758e Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/usb/r8152.c
	net/netfilter/nfnetlink.c

Both r8152 and nfnetlink conflicts were simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-02 11:25:43 -07:00
Pablo Neira Ayuso fc04733a1a netfilter: nfnetlink: use original skbuff when committing/aborting
This allows us to access the original content of the batch from
the commit and the abort paths.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-19 11:14:42 +02:00
Pablo Neira Ayuso cbb8125eb4 netfilter: nfnetlink: deliver netlink errors on batch completion
We have to wait until the full batch has been processed to deliver the
netlink error messages to userspace. Otherwise, we may deliver
duplicated errors to userspace in case that we need to abort and replay
the transaction if any of the required modules needs to be autoloaded.

A simple way to reproduce this (assumming nft_meta is not loaded) with
the following test file:

 add table filter
 add chain filter test
 add chain bad test                 # intentional wrong unexistent table
 add rule filter test meta mark 0

Then, when trying to load the batch:

 # nft -f test
 test:4:1-19: Error: Could not process rule: No such file or directory
 add chain bad test
 ^^^^^^^^^^^^^^^^^^^
 test:4:1-19: Error: Could not process rule: No such file or directory
 add chain bad test
 ^^^^^^^^^^^^^^^^^^^

The error is reported twice, once when the batch is aborted due to
missing nft_meta and another when it is fully processed.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-03 16:56:23 +02:00