A userspace listener may send (bogus) NF_STOLEN verdict, which causes skb leak.
This problem was previously fixed via
64507fdbc2 (netfilter:
nf_queue: fix NF_STOLEN skb leak) but this had to be reverted because
NF_STOLEN can also be returned by a netfilter hook when iterating the
rules in nf_reinject.
Reject userspace NF_STOLEN verdict, as suggested by Michal Miroslaw.
This is complementary to commit fad5444043
(netfilter: avoid double free in nf_reinject).
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.
MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)
Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation. So the periodic
regeneration and 8-bit counter have been removed. We compute and
use a full 32-bit sequence number.
For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.
Reported-by: Dan Kaminsky <dan@doxpara.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipq_build_packet_message() in net/ipv4/netfilter/ip_queue.c and
net/ipv6/netfilter/ip6_queue.c contain a small potential mem leak as
far as I can tell.
We allocate memory for 'skb' with alloc_skb() annd then call
nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
NLMSG_PUT is a macro
NLMSG_PUT(skb, pid, seq, type, len) \
NLMSG_NEW(skb, pid, seq, type, len, 0)
that expands to NLMSG_NEW, which is also a macro which expands to:
NLMSG_NEW(skb, pid, seq, type, len, flags) \
({ if (unlikely(skb_tailroom(skb) < (int)NLMSG_SPACE(len))) \
goto nlmsg_failure; \
__nlmsg_put(skb, pid, seq, type, len, flags); })
If we take the true branch of the 'if' statement and 'goto
nlmsg_failure', then we'll, at that point, return from
ipq_build_packet_message() without having assigned 'skb' to anything
and we'll leak the memory we allocated for it when it goes out of
scope.
Fix this by placing a 'kfree(skb)' at 'nlmsg_failure'.
I admit that I do not know how likely this to actually happen or even
if there's something that guarantees that it will never happen - I'm
not that familiar with this code, but if that is so, I've not been
able to spot it.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Make the case labels the same indent as the switch.
git diff -w shows miscellaneous 80 column wrapping,
comment reflowing and a comment for a useless gcc
warning for an otherwise unused default: case.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid creating input routes with ip_route_me_harder.
It does not work for locally generated packets. Instead,
restrict sockets to provide valid saddr for output route (or
unicast saddr for transparent proxy). For other traffic
allow saddr to be unicast or local but if callers forget
to check saddr type use 0 for the output route.
The resulting handling should be:
- REJECT TCP:
- in INPUT we can provide addr_type = RTN_LOCAL but
better allow rejecting traffic delivered with
local route (no IP address => use RTN_UNSPEC to
allow also RTN_UNICAST).
- FORWARD: RTN_UNSPEC => allow RTN_LOCAL/RTN_UNICAST
saddr, add fix to ignore RTN_BROADCAST and RTN_MULTICAST
- OUTPUT: RTN_UNSPEC
- NAT, mangle, ip_queue, nf_ip_reroute: RTN_UNSPEC in LOCAL_OUT
- IPVS:
- use RTN_LOCAL in LOCAL_OUT and FORWARD after SNAT
to restrict saddr to be local
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are enough instances of this:
iph->frag_off & htons(IP_MF | IP_OFFSET)
that a helper function is probably warranted.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid double seq adjustment for loopback traffic
because it causes silent repetition of TCP data. One
example is passive FTP with DNAT rule and difference in the
length of IP addresses.
This patch adds check if packet is sent and
received via loopback device. As the same conntrack is
used both for outgoing and incoming direction, we restrict
seq adjustment to happen only in POSTROUTING.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Patrick McHardy <kaber@trash.net>
By default, when broadcast or multicast packet are sent from a local
application, they are sent to the interface then looped by the kernel
to other local applications, going throught netfilter hooks in the
process.
These looped packet have their MAC header removed from the skb by the
kernel looping code. This confuse various netfilter's netlink queue,
netlink log and the legacy ip_queue, because they try to extract a
hardware address from these packets, but extracts a part of the IP
header instead.
This patch prevent NFQUEUE, NFLOG and ip_QUEUE to include a MAC header
if there is none in the packet.
Signed-off-by: Nicolas Cavallari <cavallar@lri.fr>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Userspace allows to specify inversion for IP header ECN matches, the
kernel silently accepts it, but doesn't invert the match result.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Check for protocol inversion in ecn_mt_check() and remove the
unnecessary runtime check for IPPROTO_TCP in ecn_mt().
Signed-off-by: Patrick McHardy <kaber@trash.net>
Netlink message lengths can't be negative, so use unsigned variables.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch fixes a refcount leak of ct objects that may occur if
l4proto->error() assigns one conntrack object to one skbuff. In
that case, we have to skip further processing in nf_conntrack_in().
With this patch, we can also fix wrong return values (-NF_ACCEPT)
for special cases in ICMP[v6] that should not bump the invalid/error
statistic counters.
Reported-by: Zoltan Menyhart <Zoltan.Menyhart@bull.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fix crash in nf_nat_csum when mangling packets
in OUTPUT hook where skb->dev is not defined, it is set
later before POSTROUTING. Problem happens for CHECKSUM_NONE.
We can check device from rt but using CHECKSUM_PARTIAL
should be safe (skb_checksum_help).
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Following error is raised (and other similar ones) :
net/ipv4/netfilter/nf_nat_standalone.c: In function ‘nf_nat_fn’:
net/ipv4/netfilter/nf_nat_standalone.c:119:2: warning: case value ‘4’
not in enumerated type ‘enum ip_conntrack_info’
gcc barfs on adding two enum values and getting a not enumerated
result :
case IP_CT_RELATED+IP_CT_IS_REPLY:
Add missing enum values
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently use a percpu spinlock to 'protect' rule bytes/packets
counters, after various attempts to use RCU instead.
Lately we added a seqlock so that get_counters() can run without
blocking BH or 'writers'. But we really only need the seqcount in it.
Spinlock itself is only locked by the current/owner cpu, so we can
remove it completely.
This cleanups api, using correct 'writer' vs 'reader' semantic.
At replace time, the get_counters() call makes sure all cpus are done
using the old table.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
'buffer' string is copied from userspace. It is not checked whether it is
zero terminated. This may lead to overflow inside of simple_strtoul().
Changli Gao suggested to copy not more than user supplied 'size' bytes.
It was introduced before the git epoch. Files "ipt_CLUSTERIP/*" are
root writable only by default, however, on some setups permissions might be
relaxed to e.g. network admin user.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
commit f3c5c1bfd4 (make ip_tables reentrant) introduced a race in
handling the stackptr restore, at the end of ipt_do_table()
We should do it before the call to xt_info_rdunlock_bh(), or we allow
cpu preemption and another cpu overwrites stackptr of original one.
A second fix is to change the underflow test to check the origptr value
instead of 0 to detect underflow, or else we allow a jump from different
hooks.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Followup patch will add ipv6 support.
ipt_addrtype.h is retained for compatibility reasons, but no longer used
by the kernel.
Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Structures ipt_replace, compat_ipt_replace, and xt_get_revision are
copied from userspace. Fields of these structs that are
zero-terminated strings are not checked. When they are used as argument
to a format string containing "%s" in request_module(), some sensitive
information is leaked to userspace via argument of spawned modprobe
process.
The first and the third bugs were introduced before the git epoch; the
second was introduced in 2722971c (v2.6.17-rc1). To trigger the bug
one should have CAP_NET_ADMIN.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Structures ipt_replace, compat_ipt_replace, and xt_get_revision are
copied from userspace. Fields of these structs that are
zero-terminated strings are not checked. When they are used as argument
to a format string containing "%s" in request_module(), some sensitive
information is leaked to userspace via argument of spawned modprobe
process.
The first bug was introduced before the git epoch; the second is
introduced by 6b7d31fc (v2.6.15-rc1); the third is introduced by
6b7d31fc (v2.6.15-rc1). To trigger the bug one should have
CAP_NET_ADMIN.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Create two sets of port member accessors, one set prefixed by fl4_*
and the other prefixed by fl6_*
This will let us to create AF optimal flow instances.
It will work because every context in which we access the ports,
we have to be fully aware of which AF the flowi is anyways.
Signed-off-by: David S. Miller <davem@davemloft.net>
In 135367b "netfilter: xtables: change xt_target.checkentry return type",
the type returned by checkentry was changed from boolean to int, but the
return values where not adjusted.
arptables: Input/output error
This broke arptables with the mangle target since it returns true
under success, which is interpreted by xtables as >0, thus
returning EIO.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
If SNAT isn't done, the wrong info maybe got by the other cts.
As the filter table is after DNAT table, the packets dropped in filter
table also bother bysource hash table.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
ret != NF_QUEUE only works in the "--queue-num 0" case; for
queues > 0 the test should be '(ret & NF_VERDICT_MASK) != NF_QUEUE'.
However, NF_QUEUE no longer DROPs the skb unconditionally if queueing
fails (due to NF_VERDICT_FLAG_QUEUE_BYPASS verdict flag), so the
re-route test should also be performed if this flag is set in the
verdict.
The full test would then look something like
&& ((ret & NF_VERDICT_MASK) == NF_QUEUE && (ret & NF_VERDICT_FLAG_QUEUE_BYPASS))
This is rather ugly, so just remove the NF_QUEUE test altogether.
The only effect is that we might perform an unnecessary route lookup
in the NF_QUEUE case.
ip6table_mangle did not have such a check.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Adding support for SNMP broadcast connection tracking. The SNMP
broadcast requests are now paired with the SNMP responses.
Thus allowing using SNMP broadcasts with firewall enabled.
Please refer to the following conversation:
http://marc.info/?l=netfilter-devel&m=125992205006600&w=2
Patrick McHardy wrote:
> > The best solution would be to add generic broadcast tracking, the
> > use of expectations for this is a bit of abuse.
> > The second best choice I guess would be to move the help() function
> > to a shared module and generalize it so it can be used for both.
This patch implements the "second best choice".
Since the netbios-ns conntrack module uses the same helper
functionality as the snmp, only one helper function is added
for both snmp and netbios-ns modules into the new object -
nf_conntrack_broadcast.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
When a packet is meant to be handled by another node of the cluster,
silently drop it instead of flooding kernel log.
Note : INVALID packets are also dropped without notice.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
My previous patch (netfilter: nf_nat: don't use atomic bit operation)
made a mistake when converting atomic_set to a normal bit 'or'.
IPS_*_BIT should be replaced with IPS_*.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Use is_vmalloc_addr() in nf_ct_free_hashtable() and get rid of
the vmalloc flags to indicate that a hash table has been allocated
using vmalloc().
Signed-off-by: Patrick McHardy <kaber@trash.net>
One iptables invocation with 135000 rules takes 35 seconds of cpu time
on a recent server, using a 32bit distro and a 64bit kernel.
We eventually trigger NMI/RCU watchdog.
INFO: rcu_sched_state detected stall on CPU 3 (t=6000 jiffies)
COMPAT mode has quadratic behavior and consume 16 bytes of memory per
rule.
Switch the xt_compat algos to use an array instead of list, and use a
binary search to locate an offset in the sorted array.
This halves memory need (8 bytes per rule), and removes quadratic
behavior [ O(N*N) -> O(N*log2(N)) ]
Time of iptables goes from 35 s to 150 ms.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Using "iptables -L" with a lot of rules have a too big BH latency.
Jesper mentioned ~6 ms and worried of frame drops.
Switch to a per_cpu seqlock scheme, so that taking a snapshot of
counters doesnt need to block BH (for this cpu, but also other cpus).
This adds two increments on seqlock sequence per ipt_do_table() call,
its a reasonable cost for allowing "iptables -L" not block BH
processing.
Reported-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In 1ae4de0cdf, the secctx was exported
via the /proc/net/netfilter/nf_conntrack and ctnetlink interfaces
instead of the secmark.
That patch introduced the use of security_secid_to_secctx() which may
return a non-zero value on error.
In one of my setups, I have NF_CONNTRACK_SECMARK enabled but no
security modules. Thus, security_secid_to_secctx() returns a negative
value that results in the breakage of the /proc and `conntrack -L'
outputs. To fix this, we skip the inclusion of secctx if the
aforementioned function fails.
This patch also fixes the dynamic netlink message size calculation
if security_secid_to_secctx() returns an error, since its logic is
also wrong.
This problem exists in Linux kernel >= 2.6.37.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Always go through a new ip4_dst_hoplimit() helper, just like ipv6.
This allowed several simplifications:
1) The interim dst_metric_hoplimit() can go as it's no longer
userd.
2) The sysctl_ip_default_ttl entry no longer needs to use
ipv4_doint_and_flush, since the sysctl is not cached in
routing cache metrics any longer.
3) ipv4_doint_and_flush no longer needs to be exported and
therefore can be marked static.
When ipv4_doint_and_flush_strategy was removed some time ago,
the external declaration in ip.h was mistakenly left around
so kill that off too.
We have to move the sysctl_ip_default_ttl declaration into
ipv4's route cache definition header net/route.h, because
currently net/ip.h (where the declaration lives now) has
a back dependency on net/route.h
Signed-off-by: David S. Miller <davem@davemloft.net>
Changed Makefile to use <modules>-y instead of <modules>-objs
because -objs is deprecated and not mentioned in
Documentation/kbuild/makefiles.txt.
Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid a sparse warning about 'ret' variable shadowing
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Use helpers to reduce number of sparse warnings
(CONFIG_SPARSE_RCU_POINTER=y)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
As we own the conntrack and the others can't see it until we confirm it,
we don't need to use atomic bit operation on ct->status.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
I am observing consistent behavior even with bridges, so let's unlock
this. xt_mac is already usable in FORWARD, too. Section 9 of
http://ebtables.sourceforge.net/br_fw_ia/br_fw_ia.html#section9 says
the MAC source address is changed, but my observation does not match
that claim -- the MAC header is retained.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
[Patrick; code inspection seems to confirm this]
Signed-off-by: Patrick McHardy <kaber@trash.net>
David S. Miller