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>
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>
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>
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>
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>
The IPv6 header is not zeroed out in alloc_skb so we must initialize
it properly unless we want to see IPv6 packets with random TOS fields
floating around. The current implementation resets the flow label
but this could be changed if deemed necessary.
We stumbled upon this issue when trying to apply a mangle rule to
the RST packet generated by the REJECT target module.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The variable 'flowlabel' is set but unused in ip6t_mangle_out().
The intention here was to compare this key to the header value after
mangling, and trigger a route lookup on mismatch.
Make it so.
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>
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>
Structures ip6t_replace, compat_ip6t_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 was
introduced in 3bc3fe5e (v2.6.25-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>
I intend to turn struct flowi into a union of AF specific flowi
structs. There will be a common structure that each variant includes
first, much like struct sock_common.
This is the first step to move in that direction.
Signed-off-by: David S. Miller <davem@davemloft.net>
The flaw was in skipping the second byte in MAC header due to increasing
the pointer AND indexed access starting at '1'.
Signed-off-by: Joerg Marx <joerg.marx@secunet.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
After commit ae90bdeaea (netfilter: fix compilation when conntrack is
disabled but tproxy is enabled) we have following warnings :
net/ipv6/netfilter/nf_conntrack_reasm.c:520:16: warning: symbol
'nf_ct_frag6_gather' was not declared. Should it be static?
net/ipv6/netfilter/nf_conntrack_reasm.c:591:6: warning: symbol
'nf_ct_frag6_output' was not declared. Should it be static?
net/ipv6/netfilter/nf_conntrack_reasm.c:612:5: warning: symbol
'nf_ct_frag6_init' was not declared. Should it be static?
net/ipv6/netfilter/nf_conntrack_reasm.c:640:6: warning: symbol
'nf_ct_frag6_cleanup' was not declared. Should it be static?
Fix this including net/netfilter/ipv6/nf_defrag_ipv6.h
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: KOVACS Krisztian <hidden@balabit.hu>
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>
The IPv6 tproxy patches split IPv6 defragmentation off of conntrack, but
failed to update the #ifdef stanzas guarding the defragmentation related
fields and code in skbuff and conntrack related code in nf_defrag_ipv6.c.
This patch adds the required #ifdefs so that IPv6 tproxy can truly be used
without connection tracking.
Original report:
http://marc.info/?l=linux-netdev&m=129010118516341&w=2
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
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>
The IPv6 tproxy patches split IPv6 defragmentation off of conntrack, but
failed to update the #ifdef stanzas guarding the defragmentation related
fields and code in skbuff and conntrack related code in nf_defrag_ipv6.c.
This patch adds the required #ifdefs so that IPv6 tproxy can truly be used
without connection tracking.
Original report:
http://marc.info/?l=linux-netdev&m=129010118516341&w=2
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Patrick McHardy <kaber@trash.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>
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>
The type of FRAG6_CB(prev)->offset is int, skb->len is *unsigned* int,
and offset is int.
Without this patch, type conversion occurred to this expression, when
(FRAG6_CB(prev)->offset + prev->len) is less than offset.
Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
One of the previous tproxy related patches split IPv6 defragmentation and
connection tracking, but did not correctly add Kconfig stanzas to handle the
new dependencies correctly. This patch fixes that by making the config options
mirror the setup we have for IPv4: a distinct config option for defragmentation
that is automatically selected by both connection tracking and
xt_TPROXY/xt_socket.
The patch also changes the #ifdefs enclosing IPv6 specific code in xt_socket
and xt_TPROXY: we only compile these in case we have ip6tables support enabled.
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Like with IPv4, TProxy needs IPv6 defragmentation but does not
require connection tracking. Since defragmentation was coupled
with conntrack, I split off the two, creating an nf_defrag_ipv6 module,
similar to the already existing nf_defrag_ipv4.
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Many of the used macros are just there for userspace compatibility.
Substitute the in-kernel code to directly use the terminal macro
and stuff the defines into #ifndef __KERNEL__ sections.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
ipt_LOG & ip6t_LOG use lot of calls to printk() and use a lock in a hope
several cpus wont mix their output in syslog.
printk() being very expensive [1], its better to call it once, on a
prebuilt and complete line. Also, with mixed IPv4 and IPv6 trafic,
separate IPv4/IPv6 locks dont avoid garbage.
I used an allocation of a 1024 bytes structure, sort of seq_printf() but
with a fixed size limit.
Use a static buffer if dynamic allocation failed.
Emit a once time alert if buffer size happens to be too short.
[1]: printk() has various features like printk_delay()...
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Change "return (EXPR);" to "return EXPR;"
return is not a function, parentheses are not required.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC5722 prohibits reassembling IPv6 fragments when some data overlaps.
Bug spotted by Zhang Zuotao <zuotao.zhang@6wind.com>.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit f3c5c1bfd4
(netfilter: xtables: make ip_tables reentrant) forgot to
also compute the jumpstack size in the compat handlers.
Result is that "iptables -I INPUT -j userchain" turns into -j DROP.
Reported by Sebastian Roesner on #netfilter, closes
http://bugzilla.netfilter.org/show_bug.cgi?id=669.
Note: arptables change is compile-tested only.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
