[ Upstream commit ee92118355 ]
Frontend callback reports EAGAIN to nfnetlink to retry a command, this
is used to signal that module autoloading is required. Unfortunately,
nlmsg_unicast() reports EAGAIN in case the receiver socket buffer gets
full, so it enters a busy-loop.
This patch updates nfnetlink_unicast() to turn EAGAIN into ENOBUFS and
to use nlmsg_unicast(). Remove the flags field in nfnetlink_unicast()
since this is always MSG_DONTWAIT in the existing code which is exactly
what nlmsg_unicast() passes to netlink_unicast() as parameter.
Fixes: 96518518cc ("netfilter: add nftables")
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6f03bf43ee ]
Kernel sends an empty NFTA_SET_USERDATA attribute with no value if
userspace adds a set with no NFTA_SET_USERDATA attribute.
Fixes: e6d8ecac9e ("netfilter: nf_tables: Add new attributes into nft_set to store user data.")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d9583cdf2f upstream.
EINVAL should be used for malformed netlink messages. New userspace
utility and old kernels might easily result in EINVAL when exercising
new set features, which is misleading.
Fixes: 8aeff920dc ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1d305ba40e upstream.
nft will loop forever if the kernel doesn't support an expression:
1. nft_expr_type_get() appends the family specific name to the module list.
2. -EAGAIN is returned to nfnetlink, nfnetlink calls abort path.
3. abort path sets ->done to true and calls request_module for the
expression.
4. nfnetlink replays the batch, we end up in nft_expr_type_get() again.
5. nft_expr_type_get attempts to append family-specific name. This
one already exists on the list, so we continue
6. nft_expr_type_get adds the generic expression name to the module
list. -EAGAIN is returned, nfnetlink calls abort path.
7. abort path encounters the family-specific expression which
has 'done' set, so it gets removed.
8. abort path requests the generic expression name, sets done to true.
9. batch is replayed.
If the expression could not be loaded, then we will end up back at 1),
because the family-specific name got removed and the cycle starts again.
Note that userspace can SIGKILL the nft process to stop the cycle, but
the desired behaviour is to return an error after the generic expr name
fails to load the expression.
Fixes: eb014de4fd ("netfilter: nf_tables: autoload modules from the abort path")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit eb014de4fd upstream.
This patch introduces a list of pending module requests. This new module
list is composed of nft_module_request objects that contain the module
name and one status field that tells if the module has been already
loaded (the 'done' field).
In the first pass, from the preparation phase, the netlink command finds
that a module is missing on this list. Then, a module request is
allocated and added to this list and nft_request_module() returns
-EAGAIN. This triggers the abort path with the autoload parameter set on
from nfnetlink, request_module() is called and the module request enters
the 'done' state. Since the mutex is released when loading modules from
the abort phase, the module list is zapped so this is iteration occurs
over a local list. Therefore, the request_module() calls happen when
object lists are in consistent state (after fulling aborting the
transaction) and the commit list is empty.
On the second pass, the netlink command will find that it already tried
to load the module, so it does not request it again and
nft_request_module() returns 0. Then, there is a look up to find the
object that the command was missing. If the module was successfully
loaded, the command proceeds normally since it finds the missing object
in place, otherwise -ENOENT is reported to userspace.
This patch also updates nfnetlink to include the reason to enter the
abort phase, which is required for this new autoload module rationale.
Fixes: ec7470b834 ("netfilter: nf_tables: store transaction list locally while requesting module")
Reported-by: syzbot+29125d208b3dae9a7019@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 826035498e upstream.
This new helper function validates that unknown family and chain type
coming from userspace do not trigger an out-of-bound array access. Bail
out in case __nft_chain_type_get() returns NULL from
nft_chain_parse_hook().
Fixes: 9370761c56 ("netfilter: nf_tables: convert built-in tables/chains to chain types")
Reported-by: syzbot+156a04714799b1d480bc@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 335178d542 upstream.
syzbot reported following crash:
list_del corruption, ffff88808c9bb000->prev is LIST_POISON2 (dead000000000122)
[..]
Call Trace:
__list_del_entry include/linux/list.h:131 [inline]
list_del_rcu include/linux/rculist.h:148 [inline]
nf_tables_commit+0x1068/0x3b30 net/netfilter/nf_tables_api.c:7183
[..]
The commit transaction list has:
NFT_MSG_NEWTABLE
NFT_MSG_NEWFLOWTABLE
NFT_MSG_DELFLOWTABLE
NFT_MSG_DELTABLE
A missing generation check during DELTABLE processing causes it to queue
the DELFLOWTABLE operation a second time, so we corrupt the list here:
case NFT_MSG_DELFLOWTABLE:
list_del_rcu(&nft_trans_flowtable(trans)->list);
nf_tables_flowtable_notify(&trans->ctx,
because we have two different DELFLOWTABLE transactions for the same
flowtable. We then call list_del_rcu() twice for the same flowtable->list.
The object handling seems to suffer from the same bug so add a generation
check too and only queue delete transactions for flowtables/objects that
are still active in the next generation.
Reported-by: syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com
Fixes: 3b49e2e94e ("netfilter: nf_tables: add flow table netlink frontend")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9332d27d79 upstream.
This WARN can trigger because some of the names fed to the module
autoload function can be of arbitrary length.
Remove the WARN and add limits for all NLA_STRING attributes.
Reported-by: syzbot+0e63ae76d117ae1c3a01@syzkaller.appspotmail.com
Fixes: 452238e8d5 ("netfilter: nf_tables: add and use helper for module autoload")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0d2c96af79 ]
Userspace might bogusly sent NFT_DATA_VERDICT in several netlink
attributes that assume NFT_DATA_VALUE. Moreover, make sure that error
path invokes nft_data_release() to decrement the reference count on the
chain object.
Fixes: 96518518cc ("netfilter: add nftables")
Fixes: 0f3cd9b369 ("netfilter: nf_tables: add range expression")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bffc124b6f ]
Only NFTA_SET_ELEM_KEY and NFTA_SET_ELEM_FLAGS make sense for elements
whose NFT_SET_ELEM_INTERVAL_END flag is set on.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Userspace never includes the NFT_BASE_CHAIN flag, this flag is inferred
from the NFTA_CHAIN_HOOK atribute. The chain update path does not allow
to update flags at this stage, the existing sanity check bogusly hits
EOPNOTSUPP in the basechain case if the offload flag is set on.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the object type doesn't implement an update operation and the user tries to
update it will silently ignore the update operation.
Fixes: aa4095a156 ("netfilter: nf_tables: fix possible null-pointer dereference in object update")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The deletion of a flowtable after a flush in the same transaction
results in EBUSY. This patch adds an activation and deactivation of
flowtables in order to update the _use_ counter.
Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This un-breaks lookups in sets that have the 'dynamic' flag set.
Given this active example configuration:
table filter {
set set1 {
type ipv4_addr
size 64
flags dynamic,timeout
timeout 1m
}
chain input {
type filter hook input priority 0; policy accept;
}
}
... this works:
nft add rule ip filter input add @set1 { ip saddr }
-> whenever rule is triggered, the source ip address is inserted
into the set (if it did not exist).
This won't work:
nft add rule ip filter input ip saddr @set1 counter
Error: Could not process rule: Operation not supported
In other words, we can add entries to the set, but then can't make
matching decision based on that set.
That is just wrong -- all set backends support lookups (else they would
not be very useful).
The failure comes from an explicit rejection in nft_lookup.c.
Looking at the history, it seems like NFT_SET_EVAL used to mean
'set contains expressions' (aka. "is a meter"), for instance something like
nft add rule ip filter input meter example { ip saddr limit rate 10/second }
or
nft add rule ip filter input meter example { ip saddr counter }
The actual meaning of NFT_SET_EVAL however, is
'set can be updated from the packet path'.
'meters' and packet-path insertions into sets, such as
'add @set { ip saddr }' use exactly the same kernel code (nft_dynset.c)
and thus require a set backend that provides the ->update() function.
The only set that provides this also is the only one that has the
NFT_SET_EVAL feature flag.
Removing the wrong check makes the above example work.
While at it, also fix the flag check during set instantiation to
allow supported combinations only.
Fixes: 8aeff920dc ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Default policy is defined as a unsigned 8-bit field, do not use a
negative value to leave it unset, use this new NFT_CHAIN_POLICY_UNSET
instead.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the net_device unregisters, clean up the offload rules before the
chain is destroy.
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds support for packet mirroring and redirection. The
nft_fwd_dup_netdev_offload() function configures the flow_action object
for the fwd and the dup actions.
Extend nft_flow_rule_destroy() to release the net_device object when the
flow_rule object is released, since nft_fwd_dup_netdev_offload() bumps
the net_device reference counter.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: wenxu <wenxu@ucloud.cn>
Add nft_offload_init() and nft_offload_exit() function to deal with the
init and the exit path of the offload infrastructure.
Rename nft_indr_block_get_and_ing_cmd() to nft_indr_block_cb().
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The "newobj" is an error pointer so we can't pass it to kfree(). It
doesn't need to be freed so we can remove that and I also renamed the
error label.
Fixes: d62d0ba97b ("netfilter: nf_tables: Introduce stateful object update operation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Not all objects have an update operation. If the object type doesn't
implement an update operation and the user tries to update it will hit
EOPNOTSUPP.
Fixes: d62d0ba97b ("netfilter: nf_tables: Introduce stateful object update operation")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds the infrastructure needed for the stateful object update
support.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds initial support for offloading basechains using the
priority range from 1 to 65535. This is restricting the netfilter
priority range to 16-bit integer since this is what most drivers assume
so far from tc. It should be possible to extend this range of supported
priorities later on once drivers are updated to support for 32-bit
integer priorities.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a rule that has already a bound anonymous set fails to be added, the
preparation phase releases the rule and the bound set. However, the
transaction object from the abort path still has a reference to the set
object that is stale, leading to a use-after-free when checking for the
set->bound field. Add a new field to the transaction that specifies if
the set is bound, so the abort path can skip releasing it since the rule
command owns it and it takes care of releasing it. After this update,
the set->bound field is removed.
[ 24.649883] Unable to handle kernel paging request at virtual address 0000000000040434
[ 24.657858] Mem abort info:
[ 24.660686] ESR = 0x96000004
[ 24.663769] Exception class = DABT (current EL), IL = 32 bits
[ 24.669725] SET = 0, FnV = 0
[ 24.672804] EA = 0, S1PTW = 0
[ 24.675975] Data abort info:
[ 24.678880] ISV = 0, ISS = 0x00000004
[ 24.682743] CM = 0, WnR = 0
[ 24.685723] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000428952000
[ 24.692207] [0000000000040434] pgd=0000000000000000
[ 24.697119] Internal error: Oops: 96000004 [#1] SMP
[...]
[ 24.889414] Call trace:
[ 24.891870] __nf_tables_abort+0x3f0/0x7a0
[ 24.895984] nf_tables_abort+0x20/0x40
[ 24.899750] nfnetlink_rcv_batch+0x17c/0x588
[ 24.904037] nfnetlink_rcv+0x13c/0x190
[ 24.907803] netlink_unicast+0x18c/0x208
[ 24.911742] netlink_sendmsg+0x1b0/0x350
[ 24.915682] sock_sendmsg+0x4c/0x68
[ 24.919185] ___sys_sendmsg+0x288/0x2c8
[ 24.923037] __sys_sendmsg+0x7c/0xd0
[ 24.926628] __arm64_sys_sendmsg+0x2c/0x38
[ 24.930744] el0_svc_common.constprop.0+0x94/0x158
[ 24.935556] el0_svc_handler+0x34/0x90
[ 24.939322] el0_svc+0x8/0xc
[ 24.942216] Code: 37280300 f9404023 91014262 aa1703e0 (f9401863)
[ 24.948336] ---[ end trace cebbb9dcbed3b56f ]---
Fixes: f6ac858589 ("netfilter: nf_tables: unbind set in rule from commit path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This object stores the flow block callbacks that are attached to this
block. Update flow_block_cb_lookup() to take this new object.
This patch restores the block sharing feature.
Fixes: da3eeb904f ("net: flow_offload: add list handling functions")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following nftables test case fails on nf-next:
tests/shell/run-tests.sh tests/shell/testcases/transactions/0011chain_0
The test case contains:
add chain x y { type filter hook input priority 0; }
add chain x y { policy drop; }"
The new test
if (chain->flags ^ flags)
return -EOPNOTSUPP;
triggers here, because chain->flags has NFT_BASE_CHAIN set, but flags
is 0 because no flag attribute was present in the policy update.
Just fetch the current flag settings of a pre-existing chain in case
userspace did not provide any.
Fixes: c9626a2cbd ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds hardware offload support for nftables through the
existing netdev_ops->ndo_setup_tc() interface, the TC_SETUP_CLSFLOWER
classifier and the flow rule API. This hardware offload support is
available for the NFPROTO_NETDEV family and the ingress hook.
Each nftables expression has a new ->offload interface, that is used to
populate the flow rule object that is attached to the transaction
object.
There is a new per-table NFT_TABLE_F_HW flag, that is set on to offload
an entire table, including all of its chains.
This patch supports for basic metadata (layer 3 and 4 protocol numbers),
5-tuple payload matching and the accept/drop actions; this also includes
basechain hardware offload only.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
nft_meta needs to pull in the nft_meta_bridge module in case that this
is a bridge family rule from the select_ops() path.
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>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset container Netfilter/IPVS update for net-next:
1) Add UDP tunnel support for ICMP errors in IPVS.
Julian Anastasov says:
This patchset is a followup to the commit that adds UDP/GUE tunnel:
"ipvs: allow tunneling with gue encapsulation".
What we do is to put tunnel real servers in hash table (patch 1),
add function to lookup tunnels (patch 2) and use it to strip the
embedded tunnel headers from ICMP errors (patch 3).
2) Extend xt_owner to match for supplementary groups, from
Lukasz Pawelczyk.
3) Remove unused oif field in flow_offload_tuple object, from
Taehee Yoo.
4) Release basechain counters from workqueue to skip synchronize_rcu()
call. From Florian Westphal.
5) Replace skb_make_writable() by skb_ensure_writable(). Patchset
from Florian Westphal.
6) Checksum support for gue encapsulation in IPVS, from Jacky Hu.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
No need to use synchronize_rcu() here, just swap the two pointers
and have the release occur from work queue after commit has completed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We can oops in nf_tables_fill_rule_info().
Its not possible to fetch previous element in rcu-protected lists
when deletions are not prevented somehow: list_del_rcu poisons
the ->prev pointer value.
Before rcu-conversion this was safe as dump operations did hold
nfnetlink mutex.
Pass previous rule as argument, obtained by keeping a pointer to
the previous rule during traversal.
Fixes: d9adf22a29 ("netfilter: nf_tables: use call_rcu in netlink dumps")
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
The following patchset contains Netfilter fixes for net:
1) Postpone chain policy update to drop after transaction is complete,
from Florian Westphal.
2) Add entry to flowtable after confirmation to fix UDP flows with
packets going in one single direction.
3) Reference count leak in dst object, from Taehee Yoo.
4) Check for TTL field in flowtable datapath, from Taehee Yoo.
5) Fix h323 conntrack helper due to incorrect boundary check,
from Jakub Jankowski.
6) Fix incorrect rcu dereference when fetching basechain stats,
from Florian Westphal.
7) Missing error check when adding new entries to flowtable,
from Taehee Yoo.
8) Use version field in nfnetlink message to honor the nfgen_family
field, from Kristian Evensen.
9) Remove incorrect configuration check for CONFIG_NF_CONNTRACK_IPV6,
from Subash Abhinov Kasiviswanathan.
10) Prevent dying entries from being added to the flowtable,
from Taehee Yoo.
11) Don't hit WARN_ON() with malformed blob in ebtables with
trailing data after last rule, reported by syzbot, patch
from Florian Westphal.
12) Remove NFT_CT_TIMEOUT enumeration, never used in the kernel
code.
13) Fix incorrect definition for NFT_LOGLEVEL_MAX, from Florian
Westphal.
This batch comes with a conflict that can be fixed with this patch:
diff --cc include/uapi/linux/netfilter/nf_tables.h
index 7bdb234f3d8c,f0cf7b0f4f35..505393c6e959
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@@ -966,6 -966,8 +966,7 @@@ enum nft_socket_keys
* @NFT_CT_DST_IP: conntrack layer 3 protocol destination (IPv4 address)
* @NFT_CT_SRC_IP6: conntrack layer 3 protocol source (IPv6 address)
* @NFT_CT_DST_IP6: conntrack layer 3 protocol destination (IPv6 address)
- * @NFT_CT_TIMEOUT: connection tracking timeout policy assigned to conntrack
+ * @NFT_CT_ID: conntrack id
*/
enum nft_ct_keys {
NFT_CT_STATE,
@@@ -991,6 -993,8 +992,7 @@@
NFT_CT_DST_IP,
NFT_CT_SRC_IP6,
NFT_CT_DST_IP6,
- NFT_CT_TIMEOUT,
+ NFT_CT_ID,
__NFT_CT_MAX
};
#define NFT_CT_MAX (__NFT_CT_MAX - 1)
That replaces the unused NFT_CT_TIMEOUT definition by NFT_CT_ID. If you prefer,
I can also solve this conflict here, just let me know.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Following splat gets triggered when nfnetlink monitor is running while
xtables-nft selftests are running:
net/netfilter/nf_tables_api.c:1272 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
1 lock held by xtables-nft-mul/27006:
#0: 00000000e0f85be9 (&net->nft.commit_mutex){+.+.}, at: nf_tables_valid_genid+0x1a/0x50
Call Trace:
nf_tables_fill_chain_info.isra.45+0x6cc/0x6e0
nf_tables_chain_notify+0xf8/0x1a0
nf_tables_commit+0x165c/0x1740
nf_tables_fill_chain_info() can be called both from dumps (rcu read locked)
or from the transaction path if a userspace process subscribed to nftables
notifications.
In the 'table dump' case, rcu_access_pointer() cannot be used: We do not
hold transaction mutex so the pointer can be NULLed right after the check.
Just unconditionally fetch the value, then have the helper return
immediately if its NULL.
In the notification case we don't hold the rcu read lock, but updates are
prevented due to transaction mutex. Use rcu_dereference_check() to make lockdep
aware of this.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When we process a long ruleset of the form
chain input {
type filter hook input priority filter; policy drop;
...
}
Then the base chain gets registered early on, we then continue to
process/validate the next messages coming in the same transaction.
Problem is that if the base chain policy is 'drop', it will take effect
immediately, which causes all traffic to get blocked until the
transaction completes or is aborted.
Fix this by deferring the policy until the transaction has been
processed and all of the rules have been flagged as active.
Reported-by: Jann Haber <jann.haber@selfnet.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size
The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().
Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.
We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated
Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)
@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)
@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)
For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.
Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.
Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.
In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.
Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().
Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:
@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)
@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I believe that "hook->num" can be up to UINT_MAX. Shifting more than
31 bits would is undefined in C but in practice it would lead to shift
wrapping. That would lead to an array overflow in nf_tables_addchain():
ops->hook = hook.type->hooks[ops->hooknum];
Fixes: fe19c04ca1 ("netfilter: nf_tables: remove nhooks field from struct nft_af_info")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
very little code, so it really doesn't make sense to have extra
modules or even a kconfig knob for this.
Merge them and make functionality available unconditionally.
The merge makes inet family route support trivial, so add it
as well here.
Before:
text data bss dec hex filename
835 832 0 1667 683 nft_chain_route_ipv4.ko
870 832 0 1702 6a6 nft_chain_route_ipv6.ko
111568 2556 529 114653 1bfdd nf_tables.ko
After:
text data bss dec hex filename
113133 2556 529 116218 1c5fa nf_tables.ko
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>