commit b22f5126a2 upstream.
Some occurences in the netfilter tree use skb_header_pointer() in
the following way ...
struct dccp_hdr _dh, *dh;
...
skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);
... where dh itself is a pointer that is being passed as the copy
buffer. Instead, we need to use &_dh as the forth argument so that
we're copying the data into an actual buffer that sits on the stack.
Currently, we probably could overwrite memory on the stack (e.g.
with a possibly mal-formed DCCP packet), but unintentionally, as
we only want the buffer to be placed into _dh variable.
Fixes: 2bc780499a ("[NETFILTER]: nf_conntrack: add DCCP protocol support")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2690d97ade upstream.
Commit 5901b6be88 attempted to introduce IPv6 support into
IRC NAT helper. By doing so, the following code seemed to be removed
by accident:
ip = ntohl(exp->master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip);
sprintf(buffer, "%u %u", ip, port);
pr_debug("nf_nat_irc: inserting '%s' == %pI4, port %u\n", buffer, &ip, port);
This leads to the fact that buffer[] was left uninitialized and
contained some stack value. When we call nf_nat_mangle_tcp_packet(),
we call strlen(buffer) on excatly this uninitialized buffer. If we
are unlucky and the skb has enough tailroom, we overwrite resp. leak
contents with values that sit on our stack into the packet and send
that out to the receiver.
Since the rather informal DCC spec [1] does not seem to specify
IPv6 support right now, we log such occurences so that admins can
act accordingly, and drop the packet. I've looked into XChat source,
and IPv6 is not supported there: addresses are in u32 and print
via %u format string.
Therefore, restore old behaviour as in IPv4, use snprintf(). The
IRC helper does not support IPv6 by now. By this, we can safely use
strlen(buffer) in nf_nat_mangle_tcp_packet() and prevent a buffer
overflow. Also simplify some code as we now have ct variable anyway.
[1] http://www.irchelp.org/irchelp/rfc/ctcpspec.html
Fixes: 5901b6be88 ("netfilter: nf_nat: support IPv6 in IRC NAT helper")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Harald Welte <laforge@gnumonks.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6aafeef03b ]
Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:
<example>
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT
and on HOSTB you do:
ping6 HOSTA -s2000 (MTU is 1500)
Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
</example>
As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.
Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 56e42441ed ]
Now when rt6_nexthop() can return nexthop address we can use it
for proper nexthop comparison of directly connected destinations.
For more information refer to commit bbb5823cf7
("netfilter: nf_conntrack: fix rt_gateway checks for H.323 helper").
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 703133de33 ]
If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.
For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.
Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2cf55125c6 upstream.
This fixes a serious bug affecting all hash types with a net element -
specifically, if a CIDR value is deleted such that none of the same size
exist any more, all larger (less-specific) values will then fail to
match. Adding back any prefix with a CIDR equal to or more specific than
the one deleted will fix it.
Steps to reproduce:
ipset -N test hash:net
ipset -A test 1.1.0.0/16
ipset -A test 2.2.2.0/24
ipset -T test 1.1.1.1 #1.1.1.1 IS in set
ipset -D test 2.2.2.0/24
ipset -T test 1.1.1.1 #1.1.1.1 IS NOT in set
This is due to the fact that the nets counter was unconditionally
decremented prior to the iteration that shifts up the entries. Now, we
first check if there is a proceeding entry and if not, decrement it and
return. Otherwise, we proceed to iterate and then zero the last element,
which, in most cases, will already be zero.
Signed-off-by: Oliver Smith <oliver@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0ceabd8387
(netfilter: ctnetlink: deliver labels to userspace) sets the event bit
when we raced with another packet, instead of raising the event bit
when the label bit is set for the first time.
commit 9b21f6a909
(netfilter: ctnetlink: allow userspace to modify labels) forgot to update
the event mask in the "conntrack already exists" case.
Both issues result in CTA_LABELS attribute not getting included in the
conntrack event.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Make sure that SCTP ports are writable when embedded in ICMP
from client, so that ip_vs_nat_icmp can translate them safely.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Similar to commit bc6bcb59 ("netfilter: xt_TCPOPTSTRIP: fix
possible mangling beyond packet boundary"), add safe fragment
handling to xt_TCPMSS.
Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
As a followup to commit 409b545a ("netfilter: xt_TCPMSS: Fix violation
of RFC879 in absence of MSS option"), John Heffner points out that IPv6
has a higher MTU than IPv4, and thus a higher minimum MSS. Update TCPMSS
target to account for this, and update RFC comment.
While at it, point to more recent reference RFC1122 instead of RFC879.
Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In (bc6bcb5 netfilter: xt_TCPOPTSTRIP: fix possible mangling beyond
packet boundary), the use of tcp_hdr was introduced. However, we
cannot assume that skb->transport_header is set for non-local packets.
Cc: Florian Westphal <fw@strlen.de>
Reported-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The entry struct has a 2 byte hole after ->port and another 4 byte
hole after ->stats.outpkts. You must have CAP_NET_ADMIN in your
namespace to hit this information leak.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The clamp-mss-to-pmtu option of the xt_TCPMSS target can cause issues
connecting to websites if there was no MSS option present in the
original SYN packet from the client. In these cases, it may add a
MSS higher than the default specified in RFC879. Fix this by never
setting a value > 536 if no MSS option was specified by the client.
This closes netfilter's bugzilla #662.
Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fix broken incomplete object dumping if the list of objects does not
fit into one single netlink message.
Reported-by: Gabriel Lazar <Gabriel.Lazar@com.utcluj.ro>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fix broken incomplete object dumping if the list of objects does not
fit into one single netlink message.
Reported-by: Gabriel Lazar <Gabriel.Lazar@com.utcluj.ro>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
kfree_rcu() requires offsetof(..., rcu_head) < 4096, which can
get violated with a sufficiently high CONFIG_IP_VS_SH_TAB_BITS.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In dump_ipv6_packet(), the "recurse" parameter is zero only if
dumping contents of a packet embedded into an ICMPv6 error
message. Therefore we want to log packet mark if recurse is
non-zero, not when it is zero.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Expire cached connection for new TCP/SCTP connection if real
server is down. Otherwise, IPVS uses the dead server for the
reused connection, instead of a new working one.
Signed-off-by: Grzegorz Lyczba <grzegorz.lyczba@gmail.com>
Acked-by: Hans Schillstrom <hans@schillstrom.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Quoting https://bugzilla.netfilter.org/show_bug.cgi?id=812:
[ ip6tables -m addrtype ]
When I tried to use in the nat/PREROUTING it messes up the
routing cache even if the rule didn't matched at all.
[..]
If I remove the --limit-iface-in from the non-working scenario, so just
use the -m addrtype --dst-type LOCAL it works!
This happens when LOCAL type matching is requested with --limit-iface-in,
and the default ipv6 route is via the interface the packet we test
arrived on.
Because xt_addrtype uses ip6_route_output, the ipv6 routing implementation
creates an unwanted cached entry, and the packet won't make it to the
real/expected destination.
Silently ignoring --limit-iface-in makes the routing work but it breaks
rule matching (--dst-type LOCAL with limit-iface-in is supposed to only
match if the dst address is configured on the incoming interface;
without --limit-iface-in it will match if the address is reachable
via lo).
The test should call ipv6_chk_addr() instead. However, this would add
a link-time dependency on ipv6.
There are two possible solutions:
1) Revert the commit that moved ipt_addrtype to xt_addrtype,
and put ipv6 specific code into ip6t_addrtype.
2) add new "nf_ipv6_ops" struct to register pointers to ipv6 functions.
While the former might seem preferable, Pablo pointed out that there
are more xt modules with link-time dependeny issues regarding ipv6,
so lets go for 2).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This target assumes that tcph->doff is well-formed, that may be well
not the case. Add extra sanity checkings to avoid possible crash due
to read/write out of the real packet boundary. After this patch, the
default action on malformed TCP packets is to drop them. Moreover,
fragments are skipped.
Reported-by: Rafal Kupka <rkupka@telemetry.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since (69b34fb netfilter: xt_LOG: add net namespace support
for xt_LOG), we hit this:
[ 4224.708977] BUG: unable to handle kernel NULL pointer dereference at 0000000000000388
[ 4224.709074] IP: [<ffffffff8147f699>] ipt_log_packet+0x29/0x270
when callling log functions from conntrack both in and out
are NULL i.e. the net pointer is invalid.
Adding struct net *net in call to nf_logfn() will secure that
there always is a vaild net ptr.
Reported as netfilter's bugzilla bug 818:
https://bugzilla.netfilter.org/show_bug.cgi?id=818
Reported-by: Ronald <ronald645@gmail.com>
Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch fixes the following compilation error:
net/netfilter/nf_log.c:373:38: error: 'struct netns_nf' has no member named 'proc_netfilter'
if procfs is not set.
The netns support for nf_log, nfnetlink_log and nfnetlink_queue_core
requires CONFIG_PROC_FS in the removal path of their respective
/proc interface since net->nf.proc_netfilter is undefined in that
case.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).
7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
