commit 520778042c upstream.
Since 3e135cd499 ("netfilter: nft_dynset: dynamic stateful expression
instantiation"), it is possible to attach stateful expressions to set
elements.
cd5125d8f5 ("netfilter: nf_tables: split set destruction in deactivate
and destroy phase") introduces conditional destruction on the object to
accomodate transaction semantics.
nft_expr_init() calls expr->ops->init() first, then check for
NFT_STATEFUL_EXPR, this stills allows to initialize a non-stateful
lookup expressions which points to a set, which might lead to UAF since
the set is not properly detached from the set->binding for this case.
Anyway, this combination is non-sense from nf_tables perspective.
This patch fixes this problem by checking for NFT_STATEFUL_EXPR before
expr->ops->init() is called.
The reporter provides a KASAN splat and a poc reproducer (similar to
those autogenerated by syzbot to report use-after-free errors). It is
unknown to me if they are using syzbot or if they use similar automated
tool to locate the bug that they are reporting.
For the record, this is the KASAN splat.
[ 85.431824] ==================================================================
[ 85.432901] BUG: KASAN: use-after-free in nf_tables_bind_set+0x81b/0xa20
[ 85.433825] Write of size 8 at addr ffff8880286f0e98 by task poc/776
[ 85.434756]
[ 85.434999] CPU: 1 PID: 776 Comm: poc Tainted: G W 5.18.0+ #2
[ 85.436023] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Fixes: 0b2d8a7b63 ("netfilter: nf_tables: add helper functions for expression handling")
Reported-and-tested-by: Aaron Adams <edg-e@nccgroup.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[Ajay: Regenerated the patch for v5.4.y]
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7b1394892d ]
Relax this condition to make add and update commands idempotent for sets
with no timeout. The eval function already checks if the set element
timeout is available and updates it if the update command is used.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0c5b7a501e upstream.
Otherwise, the newly create element shows no timeout when listing the
ruleset. If the set definition does not specify a default timeout, then
the set element only shows the expiration time, but not the timeout.
This is a problem when restoring a stateful ruleset listing since it
skips the timeout policy entirely.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 95cd4bca7b upstream.
If userspace requests a feature which is not available the original set
definition, then bail out with EOPNOTSUPP. If userspace sends
unsupported dynset flags (new feature not supported by this kernel),
then report EOPNOTSUPP to userspace. EINVAL should be only used to
report malformed netlink messages from userspace.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 917d80d376 ]
Use nf_msecs_to_jiffies64 and nf_jiffies64_to_msecs as provided by
8e1102d5a1 ("netfilter: nf_tables: support timeouts larger than 23
days"), otherwise ruleset listing breaks.
Fixes: a8b1e36d0d ("netfilter: nft_dynset: fix element timeout for HZ != 1000")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This patch implements the delete operation from the ruleset.
It implements a new delete() function in nft_set_rhash. It is simpler
to use than the already existing remove(), because it only takes the set
and the key as arguments, whereas remove() expects a full
nft_set_elem structure.
Signed-off-by: Ander Juaristi <a@juaristi.eus>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Resolve conflict between d2912cb15b ("treewide: Replace GPLv2
boilerplate/reference with SPDX - rule 500") removing the GPL disclaimer
and fe03d47456 ("Update my email address") which updates Jozsef
Kadlecsik's email.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, the expiration of every element in a set or map
is a read-only parameter generated at kernel side.
This change will permit to set a certain expiration date
per element that will be required, for example, during
stateful replication among several nodes.
This patch handles the NFTA_SET_ELEM_EXPIRATION in order
to configure the expiration parameter per element, or
will use the timeout in the case that the expiration
is not set.
Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The nf_tables.h header is used in a lot of files, but it turns out
that there is only one actual user of nft_expr_clone().
Hence we relocate that function to be with the one consumer of it
and avoid having to process it with CPP for all the other files.
This will also enable a reduction in the other headers that the
nf_tables.h itself has to include just to be stand-alone, hence
a pending further significant reduction in the CPP content that
needs to get processed for each netfilter file.
Note that the explicit "inline" has been dropped as part of this
relocation. In similar changes to this, I believe Dave has asked
this be done, so we free up gcc to make the choice of whether to
inline or not.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Set deletion after flush coming in the same batch results in EBUSY. Add
set use counter to track the number of references to this set from
rules. We cannot rely on the list of bindings for this since such list
is still populated from the preparation phase.
Reported-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
An ipvlan bug fix in 'net' conflicted with the abstraction away
of the IPV6 specific support in 'net-next'.
Similarly, a bug fix for mlx5 in 'net' conflicted with the flow
action conversion in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Anonymous sets that are bound to rules from the same transaction trigger
a kernel splat from the abort path due to double set list removal and
double free.
This patch updates the logic to search for the transaction that is
responsible for creating the set and disable the set list removal and
release, given the rule is now responsible for this. Lookup is reverse
since the transaction that adds the set is likely to be at the tail of
the list.
Moreover, this patch adds the unbind step to deliver the event from the
commit path. This should not be done from the worker thread, since we
have no guarantees of in-order delivery to the listener.
This patch removes the assumption that both activate and deactivate
callbacks need to be provided.
Fixes: cd5125d8f5 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: Mikhail Morfikov <mmorfikov@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With CONFIG_RETPOLINE its faster to add an if (ptr == &foo_func)
check and and use direct calls for all the built-in expressions.
~15% improvement in pathological cases.
checkpatch doesn't like the X macro due to the embedded return statement,
but the macro has a very limited scope so I don't think its a problem.
I would like to avoid bugs of the form
If (e->ops->eval == (unsigned long)nft_foo_eval)
nft_bar_eval();
and open-coded if ()/else if()/else cascade, thus the macro.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Splits unbind_set into destroy_set and unbinding operation.
Unbinding removes set from lists (so new transaction would not
find it anymore) but keeps memory allocated (so packet path continues
to work).
Rebind function is added to allow unrolling in case transaction
that wants to remove set is aborted.
Destroy function is added to free the memory, but this could occur
outside of transaction in the future.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Continue to use nftnl subsys mutex to protect (un)registration of hook types,
expressions and so on, but force batch operations to do their own
locking.
This allows distinct net namespaces to perform transactions in parallel.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
NFT_SET_EVAL is signalling the kernel that this sets can be updated from
the evaluation path, even if there are no expressions attached to the
element. Otherwise, set updates with no expressions fail. Update
description to describe the right semantics.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use garbage collector to schedule removal of elements based of feedback
from expression that this element comes with. Therefore, the garbage
collector is not guided by timeout expirations in this new mode.
The new connlimit expression sets on the NFT_EXPR_GC flag to enable this
behaviour, the dynset expression needs to explicitly enable the garbage
collector via set->ops->gc_init call.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This must now use a 64bit jiffies value, else we set
a bogus timeout on 32bit.
Fixes: 8e1102d5a1 ("netfilter: nf_tables: support timeouts larger than 23 days")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft rejects rules that lack a timeout and a size limit when they're used
to add elements from packet path.
Pick a sane upperlimit instead of rejecting outright.
The upperlimit is visible to userspace, just as if it would have been
given during set declaration.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.
Signed-off-by: Luis de Bethencourt <luisbg@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS/OVS fixes for net
The following patchset contains a rather large batch of Netfilter, IPVS
and OVS fixes for your net tree. This includes fixes for ctnetlink, the
userspace conntrack helper infrastructure, conntrack OVS support,
ebtables DNAT target, several leaks in error path among other. More
specifically, they are:
1) Fix reference count leak in the CT target error path, from Gao Feng.
2) Remove conntrack entry clashing with a matching expectation, patch
from Jarno Rajahalme.
3) Fix bogus EEXIST when registering two different userspace helpers,
from Liping Zhang.
4) Don't leak dummy elements in the new bitmap set type in nf_tables,
from Liping Zhang.
5) Get rid of module autoload from conntrack update path in ctnetlink,
we don't need autoload at this late stage and it is happening with
rcu read lock held which is not good. From Liping Zhang.
6) Fix deadlock due to double-acquire of the expect_lock from conntrack
update path, this fixes a bug that was introduced when the central
spinlock got removed. Again from Liping Zhang.
7) Safe ct->status update from ctnetlink path, from Liping. The expect_lock
protection that was selected when the central spinlock was removed was
not really protecting anything at all.
8) Protect sequence adjustment under ct->lock.
9) Missing socket match with IPv6, from Peter Tirsek.
10) Adjust skb->pkt_type of DNAT'ed frames from ebtables, from
Linus Luessing.
11) Don't give up on evaluating the expression on new entries added via
dynset expression in nf_tables, from Liping Zhang.
12) Use skb_checksum() when mangling icmpv6 in IPv6 NAT as this deals
with non-linear skbuffs.
13) Don't allow IPv6 service in IPVS if no IPv6 support is available,
from Paolo Abeni.
14) Missing mutex release in error path of xt_find_table_lock(), from
Dan Carpenter.
15) Update maintainers files, Netfilter section. Add Florian to the
file, refer to nftables.org and change project status from Supported
to Maintained.
16) Bail out on mismatching extensions in element updates in nf_tables.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, after adding the following nft rules:
# nft add set x target1 { type ipv4_addr \; flags timeout \;}
# nft add rule x y set add ip daddr timeout 1d @target1 counter
the counters will always be zero despite of the elements are added
to the dynamic set "target1" or not, as we will break the nft expr
traversal unconditionally:
# nft list ruleset
...
set target1 {
...
elements = { 8.8.8.8 expires 23h59m53s}
}
chain output {
...
set add ip daddr timeout 1d @target1 counter packets 0 bytes 0
^ ^
...
}
Since we add the elements to the set successfully, we should continue
to the next expression.
Additionally, if elements are added to "flow table" successfully, we
will _always_ continue to the next expr, even if the operation is
_OP_ADD. So it's better to keep them to be consistent.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Reported-by: Robert White <rwhite@pobox.com>
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This new function consolidates set lookup via either name or ID by
introducing a new nft_set_lookup() function. Replace existing spots
where we can use this too.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, if the user add a stateful object with the name size exceed
NFT_OBJ_MAXNAMELEN - 1 (i.e. 31), we truncate it down to 31 silently.
This is not friendly, furthermore, this will cause duplicated stateful
objects when the first 31 characters of the name is same. So limit the
stateful object's name size to NFT_OBJ_MAXNAMELEN - 1.
After apply this patch, error message will be printed out like this:
# name_32=$(printf "%0.sQ" {1..32})
# nft add counter filter $name_32
<cmdline>:1:1-52: Error: Could not process rule: Numerical result out
of range
add counter filter QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Also this patch cleans up the codes which missing the name size limit
validation in nftables.
Fixes: e50092404c ("netfilter: nf_tables: add stateful objects")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Some basic expressions are built into nf_tables.ko, such as nft_cmp,
nft_lookup, nft_range and so on. But these basic expressions' init
routine is a little ugly, too many goto errX labels, and we forget
to call nft_range_module_exit in the exit routine, although it is
harmless.
Acctually, the init and exit routines of these basic expressions
are same, i.e. do nft_register_expr in the init routine and do
nft_unregister_expr in the exit routine.
So it's better to arrange them into an array and deal with them
together.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When nft_expr_clone failed, a series of problems will happen:
1. module refcnt will leak, we call __module_get at the beginning but
we forget to put it back if ops->clone returns fail
2. memory will be leaked, if clone fail, we just return NULL and forget
to free the alloced element
3. set->nelems will become incorrect when set->size is specified. If
clone fail, we should decrease the set->nelems
Now this patch fixes these problems. And fortunately, clone fail will
only happen on counter expression when memory is exhausted.
Fixes: 086f332167 ("netfilter: nf_tables: add clone interface to expression operations")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When CONFIG_NFT_SET_HASH is not enabled and I input the following rule:
"nft add rule filter output flow table test {ip daddr counter }", kernel
panic happened on my system:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [< (null)>] (null)
[...]
Call Trace:
[<ffffffffa0590466>] ? nft_dynset_eval+0x56/0x100 [nf_tables]
[<ffffffffa05851bb>] nft_do_chain+0xfb/0x4e0 [nf_tables]
[<ffffffffa0432f01>] ? nf_conntrack_tuple_taken+0x61/0x210 [nf_conntrack]
[<ffffffffa0459ea6>] ? get_unique_tuple+0x136/0x560 [nf_nat]
[<ffffffffa043bca1>] ? __nf_ct_ext_add_length+0x111/0x130 [nf_conntrack]
[<ffffffffa045a357>] ? nf_nat_setup_info+0x87/0x3b0 [nf_nat]
[<ffffffff81761e27>] ? ipt_do_table+0x327/0x610
[<ffffffffa045a6d7>] ? __nf_nat_alloc_null_binding+0x57/0x80 [nf_nat]
[<ffffffffa059f21f>] nft_ipv4_output+0xaf/0xd0 [nf_tables_ipv4]
[<ffffffff81702515>] nf_iterate+0x55/0x60
[<ffffffff81702593>] nf_hook_slow+0x73/0xd0
Because in rbtree type set, ops->update is not implemented. So just keep
it simple, in such case, report -EOPNOTSUPP to the user space.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With HZ=100 element timeout in dynamic sets (i.e. flow tables) is 10 times
higher than configured.
Add proper conversion to/from jiffies, when interacting with userspace.
I tested this on Linux 4.8.1, and it applies cleanly to current nf and
nf-next trees.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Anders K. Pedersen <akp@cohaesio.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The dynset expression matches if we can fit a new entry into the set.
If there is no room for it, then it breaks the rule evaluation.
This patch introduces the inversion flag so you can add rules to
explicitly drop packets that don't fit into the set. For example:
# nft filter input flow table xyz size 4 { ip saddr timeout 120s counter } overflow drop
This is useful to provide a replacement for connlimit.
For the rule above, every new entry uses the IPv4 address as key in the
set, this entry gets a timeout of 120 seconds that gets refresh on every
packet seen. If we get new flow and our set already contains 4 entries
already, then this packet is dropped.
You can already express this in positive logic, assuming default policy
to drop:
# nft filter input flow table xyz size 4 { ip saddr timeout 10s counter } accept
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nla_data() is now aligned on a 64-bit area.
A temporary version (nla_put_be64_32bit()) is added for nla_put_net64().
This function is removed in the next patch.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the conversion of the counter expressions to make it percpu, we
need to clone the percpu memory area, otherwise we crash when using
counters from flow tables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Support instantiating stateful expressions based on a template that
are associated with dynamically created set entries. The expressions
are evaluated when adding or updating the set element.
This allows to maintain per flow state using the existing set
infrastructure and expression types, with arbitrary definitions of
a flow.
Usage is currently restricted to anonymous sets, meaning only a single
binding can exist, since the desired semantics of multiple independant
bindings haven't been defined so far.
Examples (userspace syntax is still WIP):
1. Limit the rate of new SSH connections per host, similar to iptables
hashlimit:
flow ip saddr timeout 60s \
limit 10/second \
accept
2. Account network traffic between each set of /24 networks:
flow ip saddr & 255.255.255.0 . ip daddr & 255.255.255.0 \
counter
3. Account traffic to each host per user:
flow skuid . ip daddr \
counter
4. Account traffic for each combination of source address and TCP flags:
flow ip saddr . tcp flags \
counter
The resulting set content after a Xmas-scan look like this:
{
192.168.122.1 . fin | psh | urg : counter packets 1001 bytes 40040,
192.168.122.1 . ack : counter packets 74 bytes 3848,
192.168.122.1 . psh | ack : counter packets 35 bytes 3144
}
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add helper functions to parse and dump register values in netlink attributes.
These helpers will later be changed to take care of translation between the
old 128 bit and the new 32 bit register numbers.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace the array of registers passed to expressions by a struct nft_regs,
containing the verdict as a seperate member, which aliases to the
NFT_REG_VERDICT register.
This is needed to seperate the verdict from the data registers completely,
so their size can be changed.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Change nft_validate_input_register() to not only validate the input
register number, but also the length of the load, and rename it to
nft_validate_register_load() to reflect that change.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new "dynset" expression for dynamic set updates.
A new set op ->update() is added which, for non existant elements,
invokes an initialization callback and inserts the new element.
For both new or existing elements the extenstion pointer is returned
to the caller to optionally perform timer updates or other actions.
Element removal is not supported so far, however that seems to be a
rather exotic need and can be added later on.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>