This nfnl subsystem allows to dump the list of all active netfiler hooks,
e.g. defrag, conntrack, nf/ip/arp/ip6tables and so on.
This helps to see what kind of features are currently enabled in
the network stack.
Sample output from nft tool using this infra:
$ nft list hook ip input
family ip hook input {
+0000000010 nft_do_chain_inet [nf_tables] # nft table firewalld INPUT
+0000000100 nf_nat_ipv4_local_in [nf_nat]
+2147483647 ipv4_confirm [nf_conntrack]
}
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Update the nfnl_info structure to add a pointer to the nfnetlink header.
This simplifies the existing codebase since this header is usually
accessed. Update existing clients to use this new field.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Update batch callbacks to use the nfnl_info structure. Rename one
clashing info variable to expr_info.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new structure to reduce callback footprint and to facilite
extensions of the nfnetlink callback interface in the future.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
No need to place it in struct net, nfnetlink is a module and usage
doesn't occur in fastpath.
Also remove rcu usage:
Not a single reader of net->nfnl uses rcu accessors.
When exit_batch callbacks are executed the net namespace is already dead
so no calls to these functions are possible anymore (else we'd get NULL
deref crash too).
If the module is removed, then modules that call any of those functions
have been removed too so no calls to nfnl functions are possible either.
The nfnl and nfl_stash pointers in struct net are no longer used, they
will be removed in a followup patch to minimize changes to struct net
(causes rebuild for entire network stack).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This removes the only reference of net->nfnl outside of the nfnetlink
module. This allows to move net->nfnl to net_generic infra.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If userspace does not include the trailing end of batch message, then
nfnetlink aborts the transaction. This allows to check that ruleset
updates trigger no errors.
After this patch, invoking this command from the prerouting chain:
# nft -c add rule x y fib saddr . oif type local
fails since oif is not supported there.
This patch fixes the lack of rule validation from the abort/check path
to catch configuration errors such as the one above.
Fixes: a654de8fdc ("netfilter: nf_tables: fix chain dependency validation")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
From time to time there are lockdep reports similar to this one:
WARNING: possible circular locking dependency detected
------------------------------------------------------
000000004f61aa56 (&table[i].mutex){+.+.}, at: nfnl_lock [nfnetlink]
but task is already holding lock:
[..] (&net->nft.commit_mutex){+.+.}, at: nf_tables_valid_genid [nf_tables]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&net->nft.commit_mutex){+.+.}:
[..]
nf_tables_valid_genid+0x18/0x60 [nf_tables]
nfnetlink_rcv_batch+0x24c/0x620 [nfnetlink]
nfnetlink_rcv+0x110/0x140 [nfnetlink]
netlink_unicast+0x12c/0x1e0
[..]
sys_sendmsg+0x18/0x40
linux_sparc_syscall+0x34/0x44
-> #0 (&table[i].mutex){+.+.}:
[..]
nfnl_lock+0x24/0x40 [nfnetlink]
ip_set_nfnl_get_byindex+0x19c/0x280 [ip_set]
set_match_v1_checkentry+0x14/0xc0 [xt_set]
xt_check_match+0x238/0x260 [x_tables]
__nft_match_init+0x160/0x180 [nft_compat]
[..]
sys_sendmsg+0x18/0x40
linux_sparc_syscall+0x34/0x44
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&net->nft.commit_mutex);
lock(&table[i].mutex);
lock(&net->nft.commit_mutex);
lock(&table[i].mutex);
Lockdep considers this an ABBA deadlock because the different nfnl subsys
mutexes reside in the same lockdep class, but this is a false positive.
CPU1 table[i] refers to the nftables subsys mutex, whereas CPU1 locks
the ipset subsys mutex.
Yi Che reported a similar lockdep splat, this time between ipset and
ctnetlink subsys mutexes.
Time to place them in distinct classes to avoid these warnings.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Frontend callback reports EAGAIN to nfnetlink to retry a command, this
is used to signal that module autoloading is required. Unfortunately,
nlmsg_unicast() reports EAGAIN in case the receiver socket buffer gets
full, so it enters a busy-loop.
This patch updates nfnetlink_unicast() to turn EAGAIN into ENOBUFS and
to use nlmsg_unicast(). Remove the flags field in nfnetlink_unicast()
since this is always MSG_DONTWAIT in the existing code which is exactly
what nlmsg_unicast() passes to netlink_unicast() as parameter.
Fixes: 96518518cc ("netfilter: add nftables")
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The user tool modinfo is used to get information on kernel modules, including a
description where it is available.
This patch adds a brief MODULE_DESCRIPTION to netfilter kernel modules
(descriptions taken from Kconfig file or code comments)
Signed-off-by: Rob Gill <rrobgill@protonmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch introduces a list of pending module requests. This new module
list is composed of nft_module_request objects that contain the module
name and one status field that tells if the module has been already
loaded (the 'done' field).
In the first pass, from the preparation phase, the netlink command finds
that a module is missing on this list. Then, a module request is
allocated and added to this list and nft_request_module() returns
-EAGAIN. This triggers the abort path with the autoload parameter set on
from nfnetlink, request_module() is called and the module request enters
the 'done' state. Since the mutex is released when loading modules from
the abort phase, the module list is zapped so this is iteration occurs
over a local list. Therefore, the request_module() calls happen when
object lists are in consistent state (after fulling aborting the
transaction) and the commit list is empty.
On the second pass, the netlink command will find that it already tried
to load the module, so it does not request it again and
nft_request_module() returns 0. Then, there is a look up to find the
object that the command was missing. If the module was successfully
loaded, the command proceeds normally since it finds the missing object
in place, otherwise -ENOENT is reported to userspace.
This patch also updates nfnetlink to include the reason to enter the
abort phase, which is required for this new autoload module rationale.
Fixes: ec7470b834 ("netfilter: nf_tables: store transaction list locally while requesting module")
Reported-by: syzbot+29125d208b3dae9a7019@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
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>
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>
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>
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>
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>
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>
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>
->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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Florian Westphal
Pablo Neira Ayuso
Eric Dumazet
Rob Gill
Johannes Berg
Kees Cook
Mateusz Jurczyk
David S. Miller
Arushi Singhal
Liping Zhang
Linus Torvalds
Phil Turnbull