The dummy ruleset I used to test the original validation change was broken,
most rules were unreachable and were not tested by mark_source_chains().
In some cases rulesets that used to load in a few seconds now require
several minutes.
sample ruleset that shows the behaviour:
echo "*filter"
for i in $(seq 0 100000);do
printf ":chain_%06x - [0:0]\n" $i
done
for i in $(seq 0 100000);do
printf -- "-A INPUT -j chain_%06x\n" $i
printf -- "-A INPUT -j chain_%06x\n" $i
printf -- "-A INPUT -j chain_%06x\n" $i
done
echo COMMIT
[ pipe result into iptables-restore ]
This ruleset will be about 74mbyte in size, with ~500k searches
though all 500k[1] rule entries. iptables-restore will take forever
(gave up after 10 minutes)
Instead of always searching the entire blob for a match, fill an
array with the start offsets of every single ipt_entry struct,
then do a binary search to check if the jump target is present or not.
After this change ruleset restore times get again close to what one
gets when reverting 3647234101 (~3 seconds on my workstation).
[1] every user-defined rule gets an implicit RETURN, so we get
300k jumps + 100k userchains + 100k returns -> 500k rule entries
Fixes: 3647234101 ("netfilter: x_tables: validate targets of jumps")
Reported-by: Jeff Wu <wujiafu@gmail.com>
Tested-by: Jeff Wu <wujiafu@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter uses multiple FWINV #defines with identical form that hide a
specific structure variable and dereference it with a invflags member.
$ git grep "#define FWINV"
include/linux/netfilter_bridge/ebtables.h:#define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg))
net/bridge/netfilter/ebtables.c:#define FWINV2(bool, invflg) ((bool) ^ !!(e->invflags & invflg))
net/ipv4/netfilter/arp_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
net/ipv4/netfilter/ip_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
net/ipv6/netfilter/ip6_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(ip6info->invflags & (invflg)))
net/netfilter/xt_tcpudp.c:#define FWINVTCP(bool, invflg) ((bool) ^ !!(tcpinfo->invflags & (invflg)))
Consolidate these macros into a single NF_INVF macro.
Miscellanea:
o Neaten the alignment around these uses
o A few lines are > 80 columns for intelligibility
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is a forward-port of the original patch from Andrzej Hajda,
he said:
"IS_ERR_VALUE should be used only with unsigned long type.
Otherwise it can work incorrectly. To achieve this function
xt_percpu_counter_alloc is modified to return unsigned long,
and its result is assigned to temporary variable to perform
error checking, before assigning to .pcnt field.
The patch follows conclusion from discussion on LKML [1][2].
[1]: http://permalink.gmane.org/gmane.linux.kernel/2120927
[2]: http://permalink.gmane.org/gmane.linux.kernel/2150581"
Original patch from Andrzej is here:
http://patchwork.ozlabs.org/patch/582970/
This patch has clashed with input validation fixes for x_tables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for your net-next
tree, mostly from Florian Westphal to sort out the lack of sufficient
validation in x_tables and connlabel preparation patches to add
nf_tables support. They are:
1) Ensure we don't go over the ruleset blob boundaries in
mark_source_chains().
2) Validate that target jumps land on an existing xt_entry. This extra
sanitization comes with a performance penalty when loading the ruleset.
3) Introduce xt_check_entry_offsets() and use it from {arp,ip,ip6}tables.
4) Get rid of the smallish check_entry() functions in {arp,ip,ip6}tables.
5) Make sure the minimal possible target size in x_tables.
6) Similar to #3, add xt_compat_check_entry_offsets() for compat code.
7) Check that standard target size is valid.
8) More sanitization to ensure that the target_offset field is correct.
9) Add xt_check_entry_match() to validate that matches are well-formed.
10-12) Three patch to reduce the number of parameters in
translate_compat_table() for {arp,ip,ip6}tables by using a container
structure.
13) No need to return value from xt_compat_match_from_user(), so make
it void.
14) Consolidate translate_table() so it can be used by compat code too.
15) Remove obsolete check for compat code, so we keep consistent with
what was already removed in the native layout code (back in 2007).
16) Get rid of target jump validation from mark_source_chains(),
obsoleted by #2.
17) Introduce xt_copy_counters_from_user() to consolidate counter
copying, and use it from {arp,ip,ip6}tables.
18,22) Get rid of unnecessary explicit inlining in ctnetlink for dump
functions.
19) Move nf_connlabel_match() to xt_connlabel.
20) Skip event notification if connlabel did not change.
21) Update of nf_connlabels_get() to make the upcoming nft connlabel
support easier.
23) Remove spinlock to read protocol state field in conntrack.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
nla_data() is now aligned on a 64-bit area.
The temporary function nla_put_be64_32bit() is removed in this patch.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The three variants use same copy&pasted code, condense this into a
helper and use that.
Make sure info.name is 0-terminated.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We're currently asserting that targetoff + targetsize <= nextoff.
Extend it to also check that targetoff is >= sizeof(xt_entry).
Since this is generic code, add an argument pointing to the start of the
match/target, we can then derive the base structure size from the delta.
We also need the e->elems pointer in a followup change to validate matches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
32bit rulesets have different layout and alignment requirements, so once
more integrity checks get added to xt_check_entry_offsets it will reject
well-formed 32bit rulesets.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently arp/ip and ip6tables each implement a short helper to check that
the target offset is large enough to hold one xt_entry_target struct and
that t->u.target_size fits within the current rule.
Unfortunately these checks are not sufficient.
To avoid adding new tests to all of ip/ip6/arptables move the current
checks into a helper, then extend this helper in followup patches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This fix adds a new reference counter (ref_netlink) for the struct ip_set.
The other reference counter (ref) can be swapped out by ip_set_swap and we
need a separate counter to keep track of references for netlink events
like dump. Using the same ref counter for dump causes a race condition
which can be demonstrated by the following script:
ipset create hash_ip1 hash:ip family inet hashsize 1024 maxelem 500000 \
counters
ipset create hash_ip2 hash:ip family inet hashsize 300000 maxelem 500000 \
counters
ipset create hash_ip3 hash:ip family inet hashsize 1024 maxelem 500000 \
counters
ipset save &
ipset swap hash_ip3 hash_ip2
ipset destroy hash_ip3 /* will crash the machine */
Swap will exchange the values of ref so destroy will see ref = 0 instead of
ref = 1. With this fix in place swap will not succeed because ipset save
still has ref_netlink on the set (ip_set_swap doesn't swap ref_netlink).
Both delete and swap will error out if ref_netlink != 0 on the set.
Note: The changes to *_head functions is because previously we would
increment ref whenever we called these functions, we don't do that
anymore.
Reviewed-by: Joshua Hunt <johunt@akamai.com>
Signed-off-by: Vishwanath Pai <vpai@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
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>
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>
ip_ct_sctp is an internal structure, embedded by the union
nf_conntrack_proto to store sctp-specific information at conntrack
entries. It has no business with UAPI.
This patch moves it from UAPI to a saner place, together with similar
structs for other protocols.
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The data extensions in ipset lacked the proper memory alignment and
thus could lead to kernel crash on several architectures. Therefore
the structures have been reorganized and alignment attributes added
where needed. The patch was tested on armv7h by Gerhard Wiesinger and
on x86_64, sparc64 by Jozsef Kadlecsik.
Reported-by: Gerhard Wiesinger <lists@wiesinger.com>
Tested-by: Gerhard Wiesinger <lists@wiesinger.com>
Tested-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
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>
As xt_action_param lives on the stack this does not bloat any
persistent data structures.
This is a first step in making netfilter code that needs to know
which network namespace it is executing in simpler.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fengguang reported, that some randconfig generated the following linker
issue with nf_ct_zone_dflt object involved:
[...]
CC init/version.o
LD init/built-in.o
net/built-in.o: In function `ipv4_conntrack_defrag':
nf_defrag_ipv4.c:(.text+0x93e95): undefined reference to `nf_ct_zone_dflt'
net/built-in.o: In function `ipv6_defrag':
nf_defrag_ipv6_hooks.c:(.text+0xe3ffe): undefined reference to `nf_ct_zone_dflt'
make: *** [vmlinux] Error 1
Given that configurations exist where we have a built-in part, which is
accessing nf_ct_zone_dflt such as the two handlers nf_ct_defrag_user()
and nf_ct6_defrag_user(), and a part that configures nf_conntrack as a
module, we must move nf_ct_zone_dflt into a fixed, guaranteed built-in
area when netfilter is configured in general.
Therefore, split the more generic parts into a common header under
include/linux/netfilter/ and move nf_ct_zone_dflt into the built-in
section that already holds parts related to CONFIG_NF_CONNTRACK in the
netfilter core. This fixes the issue on my side.
Fixes: 308ac9143e ("netfilter: nf_conntrack: push zone object into functions")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
- Move the nfnl_acct_list into the network namespace, initialize
and destroy it per namespace
- Keep track of refcnt on nfacct objects, the old logic does not
longer work with a per namespace list
- Adjust xt_nfacct to pass the namespace when registring objects
Signed-off-by: Andreas Schultz <aschultz@tpip.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Don't bother testing if we need to switch to alternate stack
unless TEE target is used.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In most cases there is no reentrancy into ip/ip6tables.
For skbs sent by REJECT or SYNPROXY targets, there is one level
of reentrancy, but its not relevant as those targets issue an absolute
verdict, i.e. the jumpstack can be clobbered since its not used
after the target issues absolute verdict (ACCEPT, DROP, STOLEN, etc).
So the only special case where it is relevant is the TEE target, which
returns XT_CONTINUE.
This patch changes ip(6)_do_table to always use the jump stack starting
from 0.
When we detect we're operating on an skb sent via TEE (percpu
nf_skb_duplicated is 1) we switch to an alternate stack to leave
the original one alone.
Since there is no TEE support for arptables, it doesn't need to
test if tee is active.
The jump stack overflow tests are no longer needed as well --
since ->stacksize is the largest call depth we cannot exceed it.
A much better alternative to the external jumpstack would be to just
declare a jumps[32] stack on the local stack frame, but that would mean
we'd have to reject iptables rulesets that used to work before.
Another alternative would be to start rejecting rulesets with a larger
call depth, e.g. 1000 -- in this case it would be feasible to allocate the
entire stack in the percpu area which would avoid one dereference.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
