[ Upstream commit 26b5934ff4 ]
No need to postpone this to the commit release path, since no packets
are walking over this object, this is accessed from control plane only.
This helped uncovered UAF triggered by races with the netlink notifier.
Fixes: 9dd732e0bd ("netfilter: nf_tables: memleak flow rule from commit path")
Reported-by: syzbot+8f747f62763bc6c32916@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d4bc8271db ]
commit release path is invoked via call_rcu and it runs lockless to
release the objects after rcu grace period. The netlink notifier handler
might win race to remove objects that the transaction context is still
referencing from the commit release path.
Call rcu_barrier() to ensure pending rcu callbacks run to completion
if the list of transactions to be destroyed is not empty.
Fixes: 6001a930ce ("netfilter: nftables: introduce table ownership")
Reported-by: syzbot+8f747f62763bc6c32916@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 96df8360db ]
Otherwise EINVAL is bogusly reported to userspace when deleting a set
element. NFTA_SET_ELEM_KEY_END does not need to be set in case of:
- insertion: if not present, start key is used as end key.
- deletion: only start key needs to be specified, end key is ignored.
Hence, relax the sanity check.
Fixes: 88cccd908d ("netfilter: nf_tables: NFTA_SET_ELEM_KEY_END requires concat and interval flags")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
It seems to me that percpu memory for chain stats started leaking since
commit 3bc158f8d0 ("netfilter: nf_tables: map basechain priority to
hardware priority") when nft_chain_offload_priority() returned an error.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 3bc158f8d0 ("netfilter: nf_tables: map basechain priority to hardware priority")
Signed-off-by: Florian Westphal <fw@strlen.de>
syzbot is reporting underflow of nft_counters_enabled counter at
nf_tables_addchain() [1], for commit 43eb8949cf ("netfilter:
nf_tables: do not leave chain stats enabled on error") missed that
nf_tables_chain_destroy() after nft_basechain_init() in the error path of
nf_tables_addchain() decrements the counter because nft_basechain_init()
makes nft_is_base_chain() return true by setting NFT_CHAIN_BASE flag.
Increment the counter immediately after returning from
nft_basechain_init().
Link: https://syzkaller.appspot.com/bug?extid=b5d82a651b71cd8a75ab [1]
Reported-by: syzbot <syzbot+b5d82a651b71cd8a75ab@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+b5d82a651b71cd8a75ab@syzkaller.appspotmail.com>
Fixes: 43eb8949cf ("netfilter: nf_tables: do not leave chain stats enabled on error")
Signed-off-by: Florian Westphal <fw@strlen.de>
Error might occur later in the nf_tables_addchain() codepath, enable
static key only after transaction has been created.
Fixes: 9f08ea8481 ("netfilter: nf_tables: keep chain counters away from hot path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since f3a2181e16 ("netfilter: nf_tables: Support for sets with
multiple ranged fields"), it possible to combine intervals and
concatenations. Later on, ef516e8625 ("netfilter: nf_tables:
reintroduce the NFT_SET_CONCAT flag") provides the NFT_SET_CONCAT flag
for userspace to report that the set stores a concatenation.
Make sure NFT_SET_CONCAT is set on if field_count is specified for
consistency. Otherwise, if NFT_SET_CONCAT is specified with no
field_count, bail out with EINVAL.
Fixes: ef516e8625 ("netfilter: nf_tables: reintroduce the NFT_SET_CONCAT flag")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These flags are mutually exclusive, report EINVAL in this case.
Fixes: aaa31047a6 ("netfilter: nftables: add catch-all set element support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the NFT_SET_CONCAT|NFT_SET_INTERVAL flags are set on, then the
netlink attribute NFTA_SET_ELEM_KEY_END must be specified. Otherwise,
NFTA_SET_ELEM_KEY_END should not be present.
For catch-all element, NFTA_SET_ELEM_KEY_END should not be present.
The NFT_SET_ELEM_INTERVAL_END is never used with this set flags
combination.
Fixes: 7b225d0b5c ("netfilter: nf_tables: add NFTA_SET_ELEM_KEY_END attribute")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the NFTA_SET_ELEM_OBJREF netlink attribute is present and
NFT_SET_OBJECT flag is set on, report EINVAL.
Move existing sanity check earlier to validate that NFT_SET_OBJECT
requires NFTA_SET_ELEM_OBJREF.
Fixes: 8aeff920dc ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
While looping to build the bitmap of used anonymous set names, check the
current set in the iteration, instead of the one that is being created.
Fixes: 37a9cc5255 ("netfilter: nf_tables: add generation mask to sets")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_tables_check_loops() can be called from rhashtable list
walk so cond_resched() cannot be used here.
Fixes: 81ea010667 ("netfilter: nf_tables: add rescheduling points during loop detection walks")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
dst->ops is set on when nft_expr_clone() fails, but module refcount has
not been bumped yet, therefore nft_expr_destroy() leads to module
reference underflow.
Fixes: 8cfd9b0f85 ("netfilter: nftables: generalize set expressions support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These are mutually exclusive, actually NFTA_SET_ELEM_KEY_END replaces
the flag notation.
Fixes: 7b225d0b5c ("netfilter: nf_tables: add NFTA_SET_ELEM_KEY_END attribute")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The generation ID is bumped from the commit path while holding the
mutex, however, netlink dump operations rely on RCU.
This patch also adds missing cb->base_eq initialization in
nf_tables_dump_set().
Fixes: 38e029f14a ("netfilter: nf_tables: set NLM_F_DUMP_INTR if netlink dumping is stale")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In nf_tables_updtable, if nf_tables_table_enable returns an error,
nft_trans_destroy is called to free the transaction object.
nft_trans_destroy() calls list_del(), but the transaction was never
placed on a list -- the list head is all zeroes, this results in
a null dereference:
BUG: KASAN: null-ptr-deref in nft_trans_destroy+0x26/0x59
Call Trace:
nft_trans_destroy+0x26/0x59
nf_tables_newtable+0x4bc/0x9bc
[..]
Its sane to assume that nft_trans_destroy() can be called
on the transaction object returned by nft_trans_alloc(), so
make sure the list head is initialised.
Fixes: 55dd6f9307 ("netfilter: nf_tables: use new transaction infrastructure to handle table")
Reported-by: mingi cho <mgcho.minic@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Extend struct nft_data_desc to add a flag field that specifies
nft_data_init() is being called for set element data.
Use it to disallow jump to implicit chain from set element, only jump
to chain via immediate expression is allowed.
Fixes: d0e2c7de92 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of parsing the data and then validate that type and length are
correct, pass a description of the expected data so it can be validated
upfront before parsing it to bail out earlier.
This patch adds a new .size field to specify the maximum size of the
data area. The .len field is optional and it is used as an input/output
field, it provides the specific length of the expected data in the input
path. If then .len field is not specified, then obtained length from the
netlink attribute is stored. This is required by cmp, bitwise, range and
immediate, which provide no netlink attribute that describes the data
length. The immediate expression uses the destination register type to
infer the expected data type.
Relying on opencoded validation of the expected data might lead to
subtle bugs as described in 7e6bc1f6ca ("netfilter: nf_tables:
stricter validation of element data").
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When doing lookups for rules on the same batch by using its ID, a rule from
a different chain can be used. If a rule is added to a chain but tries to
be positioned next to a rule from a different chain, it will be linked to
chain2, but the use counter on chain1 would be the one to be incremented.
When looking for rules by ID, use the chain that was used for the lookup by
name. The chain used in the context copied to the transaction needs to
match that same chain. That way, struct nft_rule does not need to get
enlarged with another member.
Fixes: 1a94e38d25 ("netfilter: nf_tables: add NFTA_RULE_ID attribute")
Fixes: 75dd48e2e4 ("netfilter: nf_tables: Support RULE_ID reference in new rule")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When doing lookups for chains on the same batch by using its ID, a chain
from a different table can be used. If a rule is added to a table but
refers to a chain in a different table, it will be linked to the chain in
table2, but would have expressions referring to objects in table1.
Then, when table1 is removed, the rule will not be removed as its linked to
a chain in table2. When expressions in the rule are processed or removed,
that will lead to a use-after-free.
When looking for chains by ID, use the table that was used for the lookup
by name, and only return chains belonging to that same table.
Fixes: 837830a4b4 ("netfilter: nf_tables: add NFTA_RULE_CHAIN_ID attribute")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When doing lookups for sets on the same batch by using its ID, a set from a
different table can be used.
Then, when the table is removed, a reference to the set may be kept after
the set is freed, leading to a potential use-after-free.
When looking for sets by ID, use the table that was used for the lookup by
name, and only return sets belonging to that same table.
This fixes CVE-2022-2586, also reported as ZDI-CAN-17470.
Reported-by: Team Orca of Sea Security (@seasecresponse)
Fixes: 958bee14d0 ("netfilter: nf_tables: use new transaction infrastructure to handle sets")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Update template to validate variable length extensions. This patch adds
a new .ext_len[id] field to the template to store the expected extension
length. This is used to sanity check the initialization of the variable
length extension.
Use PTR_ERR() in nft_set_elem_init() to report errors since, after this
update, there are two reason why this might fail, either because of
ENOMEM or insufficient room in the extension field (EINVAL).
Kernels up until 7e6bc1f6ca ("netfilter: nf_tables: stricter
validation of element data") allowed to copy more data to the extension
than was allocated. This ext_len field allows to validate if the
destination has the correct size as additional check.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add explicit rescheduling points during ruleset walk.
Switching to a faster algorithm is possible but this is a much
smaller change, suitable for nf tree.
Link: https://bugzilla.netfilter.org/show_bug.cgi?id=1460
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
BUG_ON can be triggered from userspace with an element with a large
userdata area. Replace it by length check and return EINVAL instead.
Over time extensions have been growing in size.
Pick a sufficiently old Fixes: tag to propagate this fix.
Fixes: 7d7402642e ("netfilter: nf_tables: variable sized set element keys / data")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Make sure element data type and length do not mismatch the one specified
by the set declaration.
Fixes: 7d7402642e ("netfilter: nf_tables: variable sized set element keys / data")
Reported-by: Hugues ANGUELKOV <hanguelkov@randorisec.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If user requests for NFT_CHAIN_HW_OFFLOAD, then check if either device
provides the .ndo_setup_tc interface or there is an indirect flow block
that has been registered. Otherwise, bail out early from the preparation
phase. Moreover, validate that family == NFPROTO_NETDEV and hook is
NF_NETDEV_INGRESS.
Fixes: c9626a2cbd ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Abort path release flow rule object, however, commit path does not.
Update code to destroy these objects before releasing the transaction.
Fixes: c9626a2cbd ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Release the list of new hooks that are pending to be registered in case
that unsupported flowtable flags are provided.
Fixes: 78d9f48f7f ("netfilter: nf_tables: add devices to existing flowtable")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The hook list is used if nft_trans_flowtable_update(trans) == true. However,
initialize this list for other cases for safety reasons.
Fixes: 78d9f48f7f ("netfilter: nf_tables: add devices to existing flowtable")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Remove inactive bool field in nft_hook object that was introduced in
abadb2f865 ("netfilter: nf_tables: delete devices from flowtable").
Move stale flowtable hooks to transaction list instead.
Deleting twice the same device does not result in ENOENT.
Fixes: abadb2f865 ("netfilter: nf_tables: delete devices from flowtable")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use kfree_rcu(ptr, rcu) variant instead as described by ae089831ff
("netfilter: nf_tables: prefer kfree_rcu(ptr, rcu) variant").
Fixes: f9a43007d3 ("netfilter: nf_tables: double hook unregistration in netns path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
__nft_release_hooks() is called from pre_netns exit path which
unregisters the hooks, then the NETDEV_UNREGISTER event is triggered
which unregisters the hooks again.
[ 565.221461] WARNING: CPU: 18 PID: 193 at net/netfilter/core.c:495 __nf_unregister_net_hook+0x247/0x270
[...]
[ 565.246890] CPU: 18 PID: 193 Comm: kworker/u64:1 Tainted: G E 5.18.0-rc7+ #27
[ 565.253682] Workqueue: netns cleanup_net
[ 565.257059] RIP: 0010:__nf_unregister_net_hook+0x247/0x270
[...]
[ 565.297120] Call Trace:
[ 565.300900] <TASK>
[ 565.304683] nf_tables_flowtable_event+0x16a/0x220 [nf_tables]
[ 565.308518] raw_notifier_call_chain+0x63/0x80
[ 565.312386] unregister_netdevice_many+0x54f/0xb50
Unregister and destroy netdev hook from netns pre_exit via kfree_rcu
so the NETDEV_UNREGISTER path see unregistered hooks.
Fixes: 767d1216bf ("netfilter: nftables: fix possible UAF over chains from packet path in netns")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
clean_net() runs in workqueue while walking over the lists, grab mutex.
Fixes: 767d1216bf ("netfilter: nftables: fix possible UAF over chains from packet path in netns")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add several sanity checks for nft_set_desc_concat_parse():
- validate desc->field_count not larger than desc->field_len array.
- field length cannot be larger than desc->field_len (ie. U8_MAX)
- total length of the concatenation cannot be larger than register array.
Joint work with Florian Westphal.
Fixes: f3a2181e16 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
Reported-by: <zhangziming.zzm@antgroup.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
Either userspace or kernelspace need to pre-fetch keys inconditionally
before comparisons for this to work. Otherwise, register tracking data
is misleading and it might result in reducing expressions which are not
yet registers.
First expression is also guaranteed to be evaluated always, however,
certain expressions break before writing data to registers, before
comparing the data, leaving the register in undetermined state.
This patch disables this infrastructure by now.
Fixes: b2d306542f ("netfilter: nf_tables: do not reduce read-only expressions")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since commit 6e1acfa387 ("netfilter: nf_tables: validate registers
coming from userspace.") nft_parse_register can return a negative value,
but the function prototype is still returning an unsigned int.
Fixes: 6e1acfa387 ("netfilter: nf_tables: validate registers coming from userspace.")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next:
1) Replace unnecessary list_for_each_entry_continue() in nf_tables,
from Jakob Koschel.
2) Add struct nf_conntrack_net_ecache to conntrack event cache and
use it, from Florian Westphal.
3) Refactor ctnetlink_dump_list(), also from Florian.
4) Bump module reference counter on cttimeout object addition/removal,
from Florian.
5) Consolidate nf_log MAC printer, from Phil Sutter.
6) Add basic logging support for unknown ethertype, from Phil Sutter.
7) Consolidate check for sysctl nf_log_all_netns toggle, also from Phil.
8) Replace hardcode value in nft_bitwise, from Jeremy Sowden.
9) Rename BASIC-like goto tags in nft_bitwise to more meaningful names,
also from Jeremy.
10) nft_fib support for reverse path filtering with policy-based routing
on iif. Extend selftests to cover for this new usecase, from Florian.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Since there is no way for list_for_each_entry_continue() to start
interating in the middle of the list they can be replaced with a call
to list_for_each_entry().
In preparation to limit the scope of the list iterator to the list
traversal loop, the list iterator variable 'rule' should not be used
past the loop.
v1->v2:
- also replace first usage of list_for_each_entry_continue() (Florian
Westphal)
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_*.c files whose NFT_EXPR_STATEFUL flag is set on need to
use __GFP_ACCOUNT flag for objects that are dynamically
allocated from the packet path.
Such objects are allocated inside nft_expr_ops->init() callbacks
executed in task context while processing netlink messages.
In addition, this patch adds accounting to nft_set_elem_expr_clone()
used for the same purposes.
Signed-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Incorrect output device in nf_egress hook, from Phill Sutter.
2) Preserve liberal flag in TCP conntrack state, reported by Sven Auhagen.
3) Use GFP_KERNEL_ACCOUNT flag for nf_tables objects, from Vasily Averin.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
nftables replaces iptables, but it lacks memcg accounting.
This patch account most of the memory allocation associated with nft
and should protect the host from misusing nft inside a memcg restricted
container.
Signed-off-by: Vasily Averin <vvs@openvz.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso