At the beginning in 2009 one patch [1] introduced collecting drop
counter in nf_conntrack_in() by returning -NF_DROP. Later, another
patch [2] changed the return value of tcp_packet() which now is
renamed to nf_conntrack_tcp_packet() from -NF_DROP to NF_DROP. As
we can see, that -NF_DROP should be corrected.
Similarly, there are other two points where the -NF_DROP is used.
Well, as NF_DROP is equal to 0, inverting NF_DROP makes no sense
as patch [2] said many years ago.
[1]
commit 7d1e04598e ("netfilter: nf_conntrack: account packets drop by tcp_packet()")
[2]
commit ec8d540969 ("netfilter: conntrack: fix dropping packet after l4proto->packet()")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which will
reduce the overall build time size of the kernel and run time memory
bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
* Remove sentinel elements from ctl_table structs
* Remove instances where an array element is zeroed out to make it look
like a sentinel. This is not longer needed and is safe after commit
c899710fe7 ("networking: Update to register_net_sysctl_sz") added
the array size to the ctl_table registration
* Remove the need for having __NF_SYSCTL_CT_LAST_SYSCTL as the
sysctl array size is now in NF_SYSCTL_CT_LAST_SYSCTL
* Remove extra element in ctl_table arrays declarations
Acked-by: Kees Cook <keescook@chromium.org> # loadpin & yama
Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To be able to constify instances of struct ctl_tables it is necessary to
remove ways through which non-const versions are exposed from the
sysctl core.
One of these is the ctl_table_arg member of struct ctl_table_header.
Constify this reference as a prerequisite for the full constification of
struct ctl_table instances.
No functional change.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In my recent commit, I missed that do_replace() handlers
use copy_from_sockptr() (which I fixed), followed
by unsafe copy_from_sockptr_offset() calls.
In all functions, we can perform the @optlen validation
before even calling xt_alloc_table_info() with the following
check:
if ((u64)optlen < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
Fixes: 0c83842df4 ("netfilter: validate user input for expected length")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ip_local_out() and other functions can pass skb->sk as function argument.
If the skb is a fragment and reassembly happens before such function call
returns, the sk must not be released.
This affects skb fragments reassembled via netfilter or similar
modules, e.g. openvswitch or ct_act.c, when run as part of tx pipeline.
Eric Dumazet made an initial analysis of this bug. Quoting Eric:
Calling ip_defrag() in output path is also implying skb_orphan(),
which is buggy because output path relies on sk not disappearing.
A relevant old patch about the issue was :
8282f27449 ("inet: frag: Always orphan skbs inside ip_defrag()")
[..]
net/ipv4/ip_output.c depends on skb->sk being set, and probably to an
inet socket, not an arbitrary one.
If we orphan the packet in ipvlan, then downstream things like FQ
packet scheduler will not work properly.
We need to change ip_defrag() to only use skb_orphan() when really
needed, ie whenever frag_list is going to be used.
Eric suggested to stash sk in fragment queue and made an initial patch.
However there is a problem with this:
If skb is refragmented again right after, ip_do_fragment() will copy
head->sk to the new fragments, and sets up destructor to sock_wfree.
IOW, we have no choice but to fix up sk_wmem accouting to reflect the
fully reassembled skb, else wmem will underflow.
This change moves the orphan down into the core, to last possible moment.
As ip_defrag_offset is aliased with sk_buff->sk member, we must move the
offset into the FRAG_CB, else skb->sk gets clobbered.
This allows to delay the orphaning long enough to learn if the skb has
to be queued or if the skb is completing the reasm queue.
In the former case, things work as before, skb is orphaned. This is
safe because skb gets queued/stolen and won't continue past reasm engine.
In the latter case, we will steal the skb->sk reference, reattach it to
the head skb, and fix up wmem accouting when inet_frag inflates truesize.
Fixes: 7026b1ddb6 ("netfilter: Pass socket pointer down through okfn().")
Diagnosed-by: Eric Dumazet <edumazet@google.com>
Reported-by: xingwei lee <xrivendell7@gmail.com>
Reported-by: yue sun <samsun1006219@gmail.com>
Reported-by: syzbot+e5167d7144a62715044c@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240326101845.30836-1-fw@strlen.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This is a cleanup patch, making code a bit more concise.
1) Use skb_network_offset(skb) in place of
(skb_network_header(skb) - skb->data)
2) Use -skb_network_offset(skb) in place of
(skb->data - skb_network_header(skb))
3) Use skb_transport_offset(skb) in place of
(skb_transport_header(skb) - skb->data)
4) Use skb_inner_transport_offset(skb) in place of
(skb_inner_transport_header(skb) - skb->data)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com> # for sfc
Signed-off-by: David S. Miller <davem@davemloft.net>
idev->cnf.hop_limit and net->ipv6.devconf_all->hop_limit
might be read locklessly, add appropriate READ_ONCE()
and WRITE_ONCE() annotations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Florian Westphal <fw@strlen.de> # for netfilter parts
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add hidden IP(6)_NF_IPTABLES_LEGACY symbol.
When any of the "old" builtin tables are enabled the "old" iptables
interface will be supported.
To disable the old set/getsockopt interface the existing options
for the builtin tables need to be turned off:
CONFIG_IP_NF_IPTABLES=m
CONFIG_IP_NF_FILTER is not set
CONFIG_IP_NF_NAT is not set
CONFIG_IP_NF_MANGLE is not set
CONFIG_IP_NF_RAW is not set
CONFIG_IP_NF_SECURITY is not set
Same for CONFIG_IP6_NF_ variants.
This allows to build a kernel that only supports ip(6)tables-nft
(iptables-over-nftables api).
In the future the _LEGACY symbol will become visible and the select
statements will be turned into 'depends on', but for now be on safe side
so "make oldconfig" won't break things.
Signed-off-by: Florian Westphal <fw@strlen.de>
An skb can be added to a neigh->arp_queue while waiting for an arp
reply. Where original skb's skb->dev can be different to neigh's
neigh->dev. For instance in case of bridging dnated skb from one veth to
another, the skb would be added to a neigh->arp_queue of the bridge.
As skb->dev can be reset back to nf_bridge->physindev and used, and as
there is no explicit mechanism that prevents this physindev from been
freed under us (for instance neigh_flush_dev doesn't cleanup skbs from
different device's neigh queue) we can crash on e.g. this stack:
arp_process
neigh_update
skb = __skb_dequeue(&neigh->arp_queue)
neigh_resolve_output(..., skb)
...
br_nf_dev_xmit
br_nf_pre_routing_finish_bridge_slow
skb->dev = nf_bridge->physindev
br_handle_frame_finish
Let's use plain ifindex instead of net_device link. To peek into the
original net_device we will use dev_get_by_index_rcu(). Thus either we
get device and are safe to use it or we don't get it and drop skb.
Fixes: c4e70a87d9 ("netfilter: bridge: rename br_netfilter.c to br_netfilter_hooks.c")
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is a preparation patch for replacing physindev with physinif on
nf_bridge_info structure. We will use dev_get_by_index_rcu to resolve
device, when needed, and it requires net to be available.
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These checks assume that the caller only returns NF_DROP without
any errno embedded in the upper bits.
This is fine right now, but followup patches will start to propagate
such errors to allow kfree_skb_drop_reason() in the called functions,
those would then indicate 'errno << 8 | NF_STOLEN'.
To not break things we have to mask those parts out.
Signed-off-by: Florian Westphal <fw@strlen.de>
Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and
placings sysctls to their own sybsystem or file to help avoid merge conflicts.
Matthew Wilcox pointed out though that if we're going to do that we might as
well also *save* space while at it and try to remove the extra last sysctl
entry added at the end of each array, a sentintel, instead of bloating the
kernel by adding a new sentinel with each array moved.
Doing that was not so trivial, and has required slowing down the moves of
kernel/sysctl.c arrays and measuring the impact on size by each new move.
The complex part of the effort to help reduce the size of each sysctl is being
done by the patient work of el señor Don Joel Granados. A lot of this is truly
painful code refactoring and testing and then trying to measure the savings of
each move and removing the sentinels. Although Joel already has code which does
most of this work, experience with sysctl moves in the past shows is we need to
be careful due to the slew of odd build failures that are possible due to the
amount of random Kconfig options sysctls use.
To that end Joel's work is split by first addressing the major housekeeping
needed to remove the sentinels, which is part of this merge request. The rest
of the work to actually remove the sentinels will be done later in future
kernel releases.
At first I was only going to send his first 7 patches of his patch series,
posted 1 month ago, but in retrospect due to the testing the changes have
received in linux-next and the minor changes they make this goes with the
entire set of patches Joel had planned: just sysctl house keeping. There are
networking changes but these are part of the house keeping too.
The preliminary math is showing this will all help reduce the overall build
time size of the kernel and run time memory consumed by the kernel by about
~64 bytes per array where we are able to remove each sentinel in the future.
That also means there is no more bloating the kernel with the extra ~64 bytes
per array moved as no new sentinels are created.
Most of this has been in linux-next for about a month, the last 7 patches took
a minor refresh 2 week ago based on feedback.
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Merge tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain:
"Long ago we set out to remove the kitchen sink on kernel/sysctl.c
arrays and placings sysctls to their own sybsystem or file to help
avoid merge conflicts. Matthew Wilcox pointed out though that if we're
going to do that we might as well also *save* space while at it and
try to remove the extra last sysctl entry added at the end of each
array, a sentintel, instead of bloating the kernel by adding a new
sentinel with each array moved.
Doing that was not so trivial, and has required slowing down the moves
of kernel/sysctl.c arrays and measuring the impact on size by each new
move.
The complex part of the effort to help reduce the size of each sysctl
is being done by the patient work of el señor Don Joel Granados. A lot
of this is truly painful code refactoring and testing and then trying
to measure the savings of each move and removing the sentinels.
Although Joel already has code which does most of this work,
experience with sysctl moves in the past shows is we need to be
careful due to the slew of odd build failures that are possible due to
the amount of random Kconfig options sysctls use.
To that end Joel's work is split by first addressing the major
housekeeping needed to remove the sentinels, which is part of this
merge request. The rest of the work to actually remove the sentinels
will be done later in future kernel releases.
The preliminary math is showing this will all help reduce the overall
build time size of the kernel and run time memory consumed by the
kernel by about ~64 bytes per array where we are able to remove each
sentinel in the future. That also means there is no more bloating the
kernel with the extra ~64 bytes per array moved as no new sentinels
are created"
* tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
sysctl: Use ctl_table_size as stopping criteria for list macro
sysctl: SIZE_MAX->ARRAY_SIZE in register_net_sysctl
vrf: Update to register_net_sysctl_sz
networking: Update to register_net_sysctl_sz
netfilter: Update to register_net_sysctl_sz
ax.25: Update to register_net_sysctl_sz
sysctl: Add size to register_net_sysctl function
sysctl: Add size arg to __register_sysctl_init
sysctl: Add size to register_sysctl
sysctl: Add a size arg to __register_sysctl_table
sysctl: Add size argument to init_header
sysctl: Add ctl_table_size to ctl_table_header
sysctl: Use ctl_table_header in list_for_each_table_entry
sysctl: Prefer ctl_table_header in proc_sysctl
Move from register_net_sysctl to register_net_sysctl_sz for all the
netfilter related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.
We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
We want to be able to enable/disable IP packet defrag from core
bpf/netfilter code. In other words, execute code from core that could
possibly be built as a module.
To help avoid symbol resolution errors, use glue hooks that the modules
will register callbacks with during module init.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Reviewed-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/f6a8824052441b72afe5285acedbd634bd3384c1.1689970773.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
icmp/icmp6 matches are baked into ip(6)_tables.ko.
This means that even if iptables-nft is used, a rule like
"-p icmp --icmp-type 1" will load the ip(6)tables modules.
Move them to xt_tcpdudp.ko instead to avoid this.
This will also allow to eventually add kconfig knobs to build kernels
that support iptables-nft but not iptables-legacy (old set/getsockopt
interface).
Signed-off-by: Florian Westphal <fw@strlen.de>
The xtables packet traverser performs an unconditional local_bh_disable(),
but the nf_tables evaluation loop does not.
Functions that are called from either xtables or nftables must assume
that they can be called in process context.
inet_twsk_deschedule_put() assumes that no softirq interrupt can occur.
If tproxy is used from nf_tables its possible that we'll deadlock
trying to aquire a lock already held in process context.
Add a small helper that takes care of this and use it.
Link: https://lore.kernel.org/netfilter-devel/401bd6ed-314a-a196-1cdc-e13c720cc8f2@balasys.hu/
Fixes: 4ed8eb6570 ("netfilter: nf_tables: Add native tproxy support")
Reported-and-tested-by: Major Dávid <major.david@balasys.hu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Fix broken listing of set elements when table has an owner.
2) Fix conntrack refcount leak in ctnetlink with related conntrack
entries, from Hangyu Hua.
3) Fix use-after-free/double-free in ctnetlink conntrack insert path,
from Florian Westphal.
4) Fix ip6t_rpfilter with VRF, from Phil Sutter.
5) Fix use-after-free in ebtables reported by syzbot, also from Florian.
6) Use skb->len in xt_length to deal with IPv6 jumbo packets,
from Xin Long.
7) Fix NETLINK_LISTEN_ALL_NSID with ctnetlink, from Florian Westphal.
8) Fix memleak in {ip_,ip6_,arp_}tables in ENOMEM error case,
from Pavel Tikhomirov.
* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: x_tables: fix percpu counter block leak on error path when creating new netns
netfilter: ctnetlink: make event listener tracking global
netfilter: xt_length: use skb len to match in length_mt6
netfilter: ebtables: fix table blob use-after-free
netfilter: ip6t_rpfilter: Fix regression with VRF interfaces
netfilter: conntrack: fix rmmod double-free race
netfilter: ctnetlink: fix possible refcount leak in ctnetlink_create_conntrack()
netfilter: nf_tables: allow to fetch set elements when table has an owner
====================
Link: https://lore.kernel.org/r/20230222092137.88637-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Here is the stack where we allocate percpu counter block:
+-< __alloc_percpu
+-< xt_percpu_counter_alloc
+-< find_check_entry # {arp,ip,ip6}_tables.c
+-< translate_table
And it can be leaked on this code path:
+-> ip6t_register_table
+-> translate_table # allocates percpu counter block
+-> xt_register_table # fails
there is no freeing of the counter block on xt_register_table fail.
Note: xt_percpu_counter_free should be called to free it like we do in
do_replace through cleanup_entry helper (or in __ip6t_unregister_table).
Probability of hitting this error path is low AFAICS (xt_register_table
can only return ENOMEM here, as it is not replacing anything, as we are
creating new netns, and it is hard to imagine that all previous
allocations succeeded and after that one in xt_register_table failed).
But it's worth fixing even the rare leak.
Fixes: 71ae0dff02 ("netfilter: xtables: use percpu rule counters")
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We are not allowed to return an error at this point.
Looking at the code it looks like ret is always 0 at this
point, but its not.
t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
... this can return a valid table, with ret != 0.
This bug causes update of table->private with the new
blob, but then frees the blob right away in the caller.
Syzbot report:
BUG: KASAN: vmalloc-out-of-bounds in __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
Read of size 4 at addr ffffc90005425000 by task kworker/u4:4/74
Workqueue: netns cleanup_net
Call Trace:
kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
__ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
ebt_unregister_table+0x35/0x40 net/bridge/netfilter/ebtables.c:1372
ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169
cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613
...
ip(6)tables appears to be ok (ret should be 0 at this point) but make
this more obvious.
Fixes: c58dd2dd44 ("netfilter: Can't fail and free after table replacement")
Reported-by: syzbot+f61594de72d6705aea03@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When calling ip6_route_lookup() for the packet arriving on the VRF
interface, the result is always the real (slave) interface. Expect this
when validating the result.
Fixes: acc641ab95 ("netfilter: rpfilter/fib: Populate flowic_l3mdev field")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
iptables/nftables support responding to tcp packets with tcp resets.
The generated tcp reset packet passes through both output and postrouting
netfilter hooks, but conntrack will never see them because the generated
skb has its ->nfct pointer copied over from the packet that triggered the
reset rule.
If the reset rule is used for established connections, this
may result in the conntrack entry to be around for a very long
time (default timeout is 5 days).
One way to avoid this would be to not copy the nf_conn pointer
so that the rest packet passes through conntrack too.
Problem is that output rules might not have the same conntrack
zone setup as the prerouting ones, so its possible that the
reset skb won't find the correct entry. Generating a template
entry for the skb seems error prone as well.
Add an explicit "closing" function that switches a confirmed
conntrack entry to closed state and wire this up for tcp.
If the entry isn't confirmed, no action is needed because
the conntrack entry will never be committed to the table.
Reported-by: Russel King <linux@armlinux.org.uk>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a 'reset' flag just like with nft_object_ops::dump. This will be
useful to reset "anonymous stateful objects", e.g. simple rule counters.
No functional change intended.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is used to track when a duplicate segment received by various
reassembly units is dropped.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently netfilter's rpfilter and fib modules implicitely initialise
->flowic_uid with 0. This is normally the root UID. However, this isn't
the case in user namespaces, where user ID 0 is mapped to a different
kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get
the root UID of the user namespace, thus keeping the same behaviour
whether or not we're running in a user namepspace.
Note, this is similar to commit 8bcfd0925e ("ipv4: add missing
initialization for flowi4_uid"), which fixed the rp_filter sysctl.
Fixes: 622ec2c9d5 ("net: core: add UID to flows, rules, and routes")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use the introduced field for correct operation with VRF devices instead
of conditionally overwriting flowic_oif. This is a partial revert of
commit b575b24b8e ("netfilter: Fix rpfilter dropping vrf packets by
mistake"), implementing a simpler solution.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Analogous to commit b575b24b8e ("netfilter: Fix rpfilter
dropping vrf packets by mistake") but for nftables fib expression:
Add special treatment of VRF devices so that typical reverse path
filtering via 'fib saddr . iif oif' expression works as expected.
Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
We will soon introduce an optional per-netns ehash.
This means we cannot use tcp_hashinfo directly in most places.
Instead, access it via net->ipv4.tcp_death_row.hashinfo.
The access will be valid only while initialising tcp_hashinfo
itself and creating/destroying each netns.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, net.netfilter.nf_conntrack_frag6_high_thresh can only be lowered.
I found this issue while investigating a probable kernel issue
causing flakes in tools/testing/selftests/net/ip_defrag.sh
In particular, these sysctl changes were ignored:
ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_high_thresh=9000000 >/dev/null 2>&1
ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_low_thresh=7000000 >/dev/null 2>&1
This change is inline with commit 8361962392 ("net/ipfrag: let ip[6]frag_high_thresh
in ns be higher than in init_net")
Fixes: 8db3d41569bb ("netfilter: nf_defrag_ipv6: use net_generic infra")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The checksum is optional for UDP packets. However nf_reject would
previously require a valid checksum to elicit a response such as
ICMP_DEST_UNREACH.
Add some logic to nf_reject_verify_csum to determine if a UDP packet has
a zero checksum and should therefore not be verified.
Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If policy-based routing using the iif selector is used, then the fib
expression fails to look up for the reverse path from the prerouting
hook because the input interface cannot be inferred. In order to support
this scenario, extend the fib expression to allow to use after the route
lookup, from the forward hook.
This patch also adds support for the input hook for usability reasons.
Since the prerouting hook cannot be used for the scenario described
above, users need two rules: one for the forward chain and another rule
for the input chain to check for the reverse path check for locally
targeted traffic.
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The fib expression stores to a register, so we can't add empty stub.
Check that the register that is being written is in fact redundant.
In most cases, this is expected to cancel tracking as re-use is
unlikely.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Skip register tracking for expressions that perform read-only operations
on the registers. Define and use a cookie pointer NFT_REDUCE_READONLY to
avoid defining stubs for these expressions.
This patch re-enables register tracking which was disabled in ed5f85d422
("netfilter: nf_tables: disable register tracking"). Follow up patches
add remaining register tracking for existing expressions.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
A latter patch will postpone the delivery_time clearing until the stack
knows the skb is being delivered locally (i.e. calling
skb_clear_delivery_time() at ip_local_deliver_finish() for IPv4
and at ip6_input_finish() for IPv6). That will allow other kernel
forwarding path (e.g. ip[6]_forward) to keep the delivery_time also.
A very similar IPv6 defrag codes have been duplicated in
multiple places: regular IPv6, nf_conntrack, and 6lowpan.
Unlike the IPv4 defrag which is done before ip_local_deliver_finish(),
the regular IPv6 defrag is done after ip6_input_finish().
Thus, no change should be needed in the regular IPv6 defrag
logic because skb_clear_delivery_time() should have been called.
6lowpan also does not need special handling on delivery_time
because it is a non-inet packet_type.
However, cf_conntrack has a case in NF_INET_PRE_ROUTING that needs
to do the IPv6 defrag earlier. Thus, it needs to save the
mono_delivery_time bit in the inet_frag_queue which is similar
to how it is handled in the previous patch for the IPv4 defrag.
This patch chooses to do it consistently and stores the mono_delivery_time
in the inet_frag_queue for all cases such that it will be easier
for the future refactoring effort on the IPv6 reasm code.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NF_FLOW_TABLE_IPV4 and NF_FLOW_TABLE_IPV6 are invisble, selected by
nothing (so they can no longer be enabled), and their last real users
have been removed (nf_flow_table_ipv6.c is empty).
Clean up the leftovers.
Fixes: c42ba4290b ("netfilter: flowtable: remove ipv4/ipv6 modules")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS for net-next:
1) Add new run_estimation toggle to IPVS to stop the estimation_timer
logic, from Dust Li.
2) Relax superfluous dynset check on NFT_SET_TIMEOUT.
3) Add egress hook, from Lukas Wunner.
4) Nowadays, almost all hook functions in x_table land just call the hook
evaluation loop. Remove remaining hook wrappers from iptables and IPVS.
From Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In rt_mt6(), when it's a nonlinear skb, the 1st skb_header_pointer()
only copies sizeof(struct ipv6_rt_hdr) to _route that rh points to.
The access by ((const struct rt0_hdr *)rh)->reserved will overflow
the buffer. So this access should be moved below the 2nd call to
skb_header_pointer().
Besides, after the 2nd skb_header_pointer(), its return value should
also be checked, othersize, *rp may cause null-pointer-ref.
v1->v2:
- clean up some old debugging log.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is possible now that the xt_table structure is passed via *priv.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is a revert of
7b1957b049 ("netfilter: nf_defrag_ipv4: use net_generic infra")
and a partial revert of
8b0adbe3e3 ("netfilter: nf_defrag_ipv6: use net_generic infra").
If conntrack is builtin and kernel is booted with:
nf_conntrack.enable_hooks=1
.... kernel will fail to boot due to a NULL deref in
nf_defrag_ipv4_enable(): Its called before the ipv4 defrag initcall is
made, so net_generic() returns NULL.
To resolve this, move the user refcount back to struct net so calls
to those functions are possible even before their initcalls have run.
Fixes: 7b1957b049 ("netfilter: nf_defrag_ipv4: use net_generic infra")
Fixes: 8b0adbe3e3 ("netfilter: nf_defrag_ipv6: use net_generic infra").
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip6tables only sets the `IP6T_F_PROTO` flag on a rule if a protocol is
specified (`-p tcp`, for example). However, if the flag is not set,
`ip6_packet_match` doesn't call `ipv6_find_hdr` for the skb, in which
case the fragment offset is left uninitialized and a garbage value is
passed to each matcher.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Protect nft_ct template with global mutex, from Pavel Skripkin.
2) Two recent commits switched inet rt and nexthop exception hashes
from jhash to siphash. If those two spots are problematic then
conntrack is affected as well, so switch voer to siphash too.
While at it, add a hard upper limit on chain lengths and reject
insertion if this is hit. Patches from Florian Westphal.
3) Fix use-after-scope in nf_socket_ipv6 reported by KASAN,
from Benjamin Hesmans.
* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
netfilter: socket: icmp6: fix use-after-scope
netfilter: refuse insertion if chain has grown too large
netfilter: conntrack: switch to siphash
netfilter: conntrack: sanitize table size default settings
netfilter: nft_ct: protect nft_ct_pcpu_template_refcnt with mutex
====================
Link: https://lore.kernel.org/r/20210903163020.13741-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Bug reported by KASAN:
BUG: KASAN: use-after-scope in inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
Call Trace:
(...)
inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
(...)
nf_sk_lookup_slow_v6 (net/ipv6/netfilter/nf_socket_ipv6.c:91
net/ipv6/netfilter/nf_socket_ipv6.c:146)
It seems that this bug has already been fixed by Eric Dumazet in the
past in:
commit 78296c97ca ("netfilter: xt_socket: fix a stack corruption bug")
But a variant of the same issue has been introduced in
commit d64d80a2cd ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")
`daddr` and `saddr` potentially hold a reference to ipv6_var that is no
longer in scope when the call to `nf_socket_get_sock_v6` is made.
Fixes: d64d80a2cd ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For historical reasons x_tables still register tables by default in the
initial namespace.
Only newly created net namespaces add the hook on demand.
This means that the init_net always pays hook cost, even if no filtering
rules are added (e.g. only used inside a single netns).
Note that the hooks are added even when 'iptables -L' is called.
This is because there is no way to tell 'iptables -A' and 'iptables -L'
apart at kernel level.
The only solution would be to register the table, but delay hook
registration until the first rule gets added (or policy gets changed).
That however means that counters are not hooked either, so 'iptables -L'
would always show 0-counters even when traffic is flowing which might be
unexpected.
This keeps table and hook registration consistent with what is already done
in non-init netns: first iptables(-save) invocation registers both table
and hooks.
This applies the same solution adopted for ebtables.
All tables register a template that contains the l3 family, the name
and a constructor function that is called when the initial table has to
be added.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Trivial conflicts in net/can/isotp.c and
tools/testing/selftests/net/mptcp/mptcp_connect.sh
scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c
to include/linux/ptp_clock_kernel.h in -next so re-apply
the fix there.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The ip6tables rpfilter match has an extra check to skip packets with
"::" source address.
Extend this to ipv6 fib expression. Else ipv6 duplicate address detection
packets will fail rpf route check -- lookup returns -ENETUNREACH.
While at it, extend the prerouting check to also cover the ingress hook.
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1543
Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This allows to change storage placement later on without changing readers.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The fragment offset in ipv4/ipv6 is a 16bit field, so use
u16 instead of unsigned int.
On 64bit: 40 bytes to 32 bytes. By extension this also reduces
nft_pktinfo (56 to 48 byte).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jason Xing