8c873e2199 ("netfilter: core: free hooks with call_rcu") removed
synchronize_net() call when unregistering basechain hook, however,
net_device removal event handler for the NFPROTO_NETDEV was not updated
to wait for RCU grace period.
Note that 835b803377 ("netfilter: nf_tables_netdev: unregister hooks
on net_device removal") does not remove basechain rules on device
removal, I was hinted to remove rules on net_device removal later, see
5ebe0b0eec ("netfilter: nf_tables: destroy basechain and rules on
netdevice removal").
Although NETDEV_UNREGISTER event is guaranteed to be handled after
synchronize_net() call, this path needs to wait for rcu grace period via
rcu callback to release basechain hooks if netns is alive because an
ongoing netlink dump could be in progress (sockets hold a reference on
the netns).
Note that nf_tables_pre_exit_net() unregisters and releases basechain
hooks but it is possible to see NETDEV_UNREGISTER at a later stage in
the netns exit path, eg. veth peer device in another netns:
cleanup_net()
default_device_exit_batch()
unregister_netdevice_many_notify()
notifier_call_chain()
nf_tables_netdev_event()
__nft_release_basechain()
In this particular case, same rule of thumb applies: if netns is alive,
then wait for rcu grace period because netlink dump in the other netns
could be in progress. Otherwise, if the other netns is going away then
no netlink dump can be in progress and basechain hooks can be released
inmediately.
While at it, turn WARN_ON() into WARN_ON_ONCE() for the basechain
validation, which should not ever happen.
Fixes: 835b803377 ("netfilter: nf_tables_netdev: unregister hooks on net_device removal")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If access to offset + length is larger than the skbuff length, then
skb_checksum() triggers BUG_ON().
skb_checksum() internally subtracts the length parameter while iterating
over skbuff, BUG_ON(len) at the end of it checks that the expected
length to be included in the checksum calculation is fully consumed.
Fixes: 7ec3f7b47b ("netfilter: nft_payload: add packet mangling support")
Reported-by: Slavin Liu <slavin-ayu@qq.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip6table_nat module unload has refcnt warning for UAF. call trace is:
WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80
Modules linked in: ip6table_nat(-)
CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:module_put+0x6f/0x80
Call Trace:
<TASK>
get_info+0x128/0x180
do_ip6t_get_ctl+0x6a/0x430
nf_getsockopt+0x46/0x80
ipv6_getsockopt+0xb9/0x100
rawv6_getsockopt+0x42/0x190
do_sock_getsockopt+0xaa/0x180
__sys_getsockopt+0x70/0xc0
__x64_sys_getsockopt+0x20/0x30
do_syscall_64+0xa2/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Concurrent execution of module unload and get_info() trigered the warning.
The root cause is as follows:
cpu0 cpu1
module_exit
//mod->state = MODULE_STATE_GOING
ip6table_nat_exit
xt_unregister_template
kfree(t)
//removed from templ_list
getinfo()
t = xt_find_table_lock
list_for_each_entry(tmpl, &xt_templates[af]...)
if (strcmp(tmpl->name, name))
continue; //table not found
try_module_get
list_for_each_entry(t, &xt_net->tables[af]...)
return t; //not get refcnt
module_put(t->me) //uaf
unregister_pernet_subsys
//remove table from xt_net list
While xt_table module was going away and has been removed from
xt_templates list, we couldnt get refcnt of xt_table->me. Check
module in xt_net->tables list re-traversal to fix it.
Fixes: fdacd57c79 ("netfilter: x_tables: never register tables by default")
Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Current release - regressions:
- posix-clock: Fix unbalanced locking in pc_clock_settime()
- netfilter: fix typo causing some targets not to load on IPv6
Current release - new code bugs:
- xfrm: policy: remove last remnants of pernet inexact list
Previous releases - regressions:
- core: fix races in netdev_tx_sent_queue()/dev_watchdog()
- bluetooth: fix UAF on sco_sock_timeout
- eth: hv_netvsc: fix VF namespace also in synthetic NIC NETDEV_REGISTER event
- eth: usbnet: fix name regression
- eth: be2net: fix potential memory leak in be_xmit()
- eth: plip: fix transmit path breakage
Previous releases - always broken:
- sched: deny mismatched skip_sw/skip_hw flags for actions created by classifiers
- netfilter: bpf: must hold reference on net namespace
- eth: virtio_net: fix integer overflow in stats
- eth: bnxt_en: replace ptp_lock with irqsave variant
- eth: octeon_ep: add SKB allocation failures handling in __octep_oq_process_rx()
Misc:
- MAINTAINERS: add Simon as an official reviewer
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from netfiler, xfrm and bluetooth.
Oddly this includes a fix for a posix clock regression; in our
previous PR we included a change there as a pre-requisite for
networking one. That fix proved to be buggy and requires the follow-up
included here. Thomas suggested we should send it, given we sent the
buggy patch.
Current release - regressions:
- posix-clock: Fix unbalanced locking in pc_clock_settime()
- netfilter: fix typo causing some targets not to load on IPv6
Current release - new code bugs:
- xfrm: policy: remove last remnants of pernet inexact list
Previous releases - regressions:
- core: fix races in netdev_tx_sent_queue()/dev_watchdog()
- bluetooth: fix UAF on sco_sock_timeout
- eth: hv_netvsc: fix VF namespace also in synthetic NIC
NETDEV_REGISTER event
- eth: usbnet: fix name regression
- eth: be2net: fix potential memory leak in be_xmit()
- eth: plip: fix transmit path breakage
Previous releases - always broken:
- sched: deny mismatched skip_sw/skip_hw flags for actions created by
classifiers
- netfilter: bpf: must hold reference on net namespace
- eth: virtio_net: fix integer overflow in stats
- eth: bnxt_en: replace ptp_lock with irqsave variant
- eth: octeon_ep: add SKB allocation failures handling in
__octep_oq_process_rx()
Misc:
- MAINTAINERS: add Simon as an official reviewer"
* tag 'net-6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (40 commits)
net: dsa: mv88e6xxx: support 4000ps cycle counter period
net: dsa: mv88e6xxx: read cycle counter period from hardware
net: dsa: mv88e6xxx: group cycle counter coefficients
net: usb: qmi_wwan: add Fibocom FG132 0x0112 composition
hv_netvsc: Fix VF namespace also in synthetic NIC NETDEV_REGISTER event
net: dsa: microchip: disable EEE for KSZ879x/KSZ877x/KSZ876x
Bluetooth: ISO: Fix UAF on iso_sock_timeout
Bluetooth: SCO: Fix UAF on sco_sock_timeout
Bluetooth: hci_core: Disable works on hci_unregister_dev
posix-clock: posix-clock: Fix unbalanced locking in pc_clock_settime()
r8169: avoid unsolicited interrupts
net: sched: use RCU read-side critical section in taprio_dump()
net: sched: fix use-after-free in taprio_change()
net/sched: act_api: deny mismatched skip_sw/skip_hw flags for actions created by classifiers
net: usb: usbnet: fix name regression
mlxsw: spectrum_router: fix xa_store() error checking
virtio_net: fix integer overflow in stats
net: fix races in netdev_tx_sent_queue()/dev_watchdog()
net: wwan: fix global oob in wwan_rtnl_policy
netfilter: xtables: fix typo causing some targets not to load on IPv6
...
- There is no NFPROTO_IPV6 family for mark and NFLOG.
- TRACE is also missing module autoload with NFPROTO_IPV6.
This results in ip6tables failing to restore a ruleset. This issue has been
reported by several users providing incomplete patches.
Very similar to Ilya Katsnelson's patch including a missing chunk in the
TRACE extension.
Fixes: 0bfcb7b71e ("netfilter: xtables: avoid NFPROTO_UNSPEC where needed")
Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Reported-by: Ilya Katsnelson <me@0upti.me>
Reported-by: Krzysztof Olędzki <ole@ans.pl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
- Fix BPF verifier to not affect subreg_def marks in its range
propagation, from Eduard Zingerman.
- Fix a truncation bug in the BPF verifier's handling of
coerce_reg_to_size_sx, from Dimitar Kanaliev.
- Fix the BPF verifier's delta propagation between linked
registers under 32-bit addition, from Daniel Borkmann.
- Fix a NULL pointer dereference in BPF devmap due to missing
rxq information, from Florian Kauer.
- Fix a memory leak in bpf_core_apply, from Jiri Olsa.
- Fix an UBSAN-reported array-index-out-of-bounds in BTF
parsing for arrays of nested structs, from Hou Tao.
- Fix build ID fetching where memory areas backing the file
were created with memfd_secret, from Andrii Nakryiko.
- Fix BPF task iterator tid filtering which was incorrectly
using pid instead of tid, from Jordan Rome.
- Several fixes for BPF sockmap and BPF sockhash redirection
in combination with vsocks, from Michal Luczaj.
- Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered,
from Andrea Parri.
- Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the
possibility of an infinite BPF tailcall, from Pu Lehui.
- Fix a build warning from resolve_btfids that bpf_lsm_key_free
cannot be resolved, from Thomas Weißschuh.
- Fix a bug in kfunc BTF caching for modules where the wrong
BTF object was returned, from Toke Høiland-Jørgensen.
- Fix a BPF selftest compilation error in cgroup-related tests
with musl libc, from Tony Ambardar.
- Several fixes to BPF link info dumps to fill missing fields,
from Tyrone Wu.
- Add BPF selftests for kfuncs from multiple modules, checking
that the correct kfuncs are called, from Simon Sundberg.
- Ensure that internal and user-facing bpf_redirect flags
don't overlap, also from Toke Høiland-Jørgensen.
- Switch to use kvzmalloc to allocate BPF verifier environment,
from Rik van Riel.
- Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic
splat under RT, from Wander Lairson Costa.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Daniel Borkmann:
- Fix BPF verifier to not affect subreg_def marks in its range
propagation (Eduard Zingerman)
- Fix a truncation bug in the BPF verifier's handling of
coerce_reg_to_size_sx (Dimitar Kanaliev)
- Fix the BPF verifier's delta propagation between linked registers
under 32-bit addition (Daniel Borkmann)
- Fix a NULL pointer dereference in BPF devmap due to missing rxq
information (Florian Kauer)
- Fix a memory leak in bpf_core_apply (Jiri Olsa)
- Fix an UBSAN-reported array-index-out-of-bounds in BTF parsing for
arrays of nested structs (Hou Tao)
- Fix build ID fetching where memory areas backing the file were
created with memfd_secret (Andrii Nakryiko)
- Fix BPF task iterator tid filtering which was incorrectly using pid
instead of tid (Jordan Rome)
- Several fixes for BPF sockmap and BPF sockhash redirection in
combination with vsocks (Michal Luczaj)
- Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered (Andrea Parri)
- Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the possibility
of an infinite BPF tailcall (Pu Lehui)
- Fix a build warning from resolve_btfids that bpf_lsm_key_free cannot
be resolved (Thomas Weißschuh)
- Fix a bug in kfunc BTF caching for modules where the wrong BTF object
was returned (Toke Høiland-Jørgensen)
- Fix a BPF selftest compilation error in cgroup-related tests with
musl libc (Tony Ambardar)
- Several fixes to BPF link info dumps to fill missing fields (Tyrone
Wu)
- Add BPF selftests for kfuncs from multiple modules, checking that the
correct kfuncs are called (Simon Sundberg)
- Ensure that internal and user-facing bpf_redirect flags don't overlap
(Toke Høiland-Jørgensen)
- Switch to use kvzmalloc to allocate BPF verifier environment (Rik van
Riel)
- Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic splat
under RT (Wander Lairson Costa)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (38 commits)
lib/buildid: Handle memfd_secret() files in build_id_parse()
selftests/bpf: Add test case for delta propagation
bpf: Fix print_reg_state's constant scalar dump
bpf: Fix incorrect delta propagation between linked registers
bpf: Properly test iter/task tid filtering
bpf: Fix iter/task tid filtering
riscv, bpf: Make BPF_CMPXCHG fully ordered
bpf, vsock: Drop static vsock_bpf_prot initialization
vsock: Update msg_count on read_skb()
vsock: Update rx_bytes on read_skb()
bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock
selftests/bpf: Add asserts for netfilter link info
bpf: Fix link info netfilter flags to populate defrag flag
selftests/bpf: Add test for sign extension in coerce_subreg_to_size_sx()
selftests/bpf: Add test for truncation after sign extension in coerce_reg_to_size_sx()
bpf: Fix truncation bug in coerce_reg_to_size_sx()
selftests/bpf: Assert link info uprobe_multi count & path_size if unset
bpf: Fix unpopulated path_size when uprobe_multi fields unset
selftests/bpf: Fix cross-compiling urandom_read
selftests/bpf: Add test for kfunc module order
...
BUG: KASAN: slab-use-after-free in __nf_unregister_net_hook+0x640/0x6b0
Read of size 8 at addr ffff8880106fe400 by task repro/72=
bpf_nf_link_release+0xda/0x1e0
bpf_link_free+0x139/0x2d0
bpf_link_release+0x68/0x80
__fput+0x414/0xb60
Eric says:
It seems that bpf was able to defer the __nf_unregister_net_hook()
after exit()/close() time.
Perhaps a netns reference is missing, because the netns has been
dismantled/freed already.
bpf_nf_link_attach() does :
link->net = net;
But I do not see a reference being taken on net.
Add such a reference and release it after hook unreg.
Note that I was unable to get syzbot reproducer to work, so I
do not know if this resolves this splat.
Fixes: 84601d6ee6 ("bpf: add bpf_link support for BPF_NETFILTER programs")
Diagnosed-by: Eric Dumazet <edumazet@google.com>
Reported-by: Lai, Yi <yi1.lai@linux.intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This fix correctly populates the `bpf_link_info.netfilter.flags` field
when user passes the `BPF_F_NETFILTER_IP_DEFRAG` flag.
Fixes: 91721c2d02 ("netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link")
Signed-off-by: Tyrone Wu <wudevelops@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Florian Westphal <fw@strlen.de>
Cc: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/20241011193252.178997-1-wudevelops@gmail.com
syzbot managed to call xt_cluster match via ebtables:
WARNING: CPU: 0 PID: 11 at net/netfilter/xt_cluster.c:72 xt_cluster_mt+0x196/0x780
[..]
ebt_do_table+0x174b/0x2a40
Module registers to NFPROTO_UNSPEC, but it assumes ipv4/ipv6 packet
processing. As this is only useful to restrict locally terminating
TCP/UDP traffic, register this for ipv4 and ipv6 family only.
Pablo points out that this is a general issue, direct users of the
set/getsockopt interface can call into targets/matches that were only
intended for use with ip(6)tables.
Check all UNSPEC matches and targets for similar issues:
- matches and targets are fine except if they assume skb_network_header()
is valid -- this is only true when called from inet layer: ip(6) stack
pulls the ip/ipv6 header into linear data area.
- targets that return XT_CONTINUE or other xtables verdicts must be
restricted too, they are incompatbile with the ebtables traverser, e.g.
EBT_CONTINUE is a completely different value than XT_CONTINUE.
Most matches/targets are changed to register for NFPROTO_IPV4/IPV6, as
they are provided for use by ip(6)tables.
The MARK target is also used by arptables, so register for NFPROTO_ARP too.
While at it, bail out if connbytes fails to enable the corresponding
conntrack family.
This change passes the selftests in iptables.git.
Reported-by: syzbot+256c348558aa5cf611a9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netfilter-devel/66fec2e2.050a0220.9ec68.0047.GAE@google.com/
Fixes: 0269ea4937 ("netfilter: xtables: add cluster match")
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
For historical reasons there are two clash resolution spots in
netfilter, one in nfnetlink_queue and one in conntrack core.
nfnetlink_queue one was added first: If a colliding entry is found, NAT
NAT transformation is reversed by calling nat engine again with altered
tuple.
See commit 368982cd7d ("netfilter: nfnetlink_queue: resolve clash for
unconfirmed conntracks") for details.
One problem is that nf_reroute() won't take an action if the queueing
doesn't occur in the OUTPUT hook, i.e. when queueing in forward or
postrouting, packet will be sent via the wrong path.
Another problem is that the scenario addressed (2nd UDP packet sent with
identical addresses while first packet is still being processed) can also
occur without any nfqueue involvement due to threaded resolvers doing
A and AAAA requests back-to-back.
This lead us to add clash resolution logic to the conntrack core, see
commit 6a757c07e5 ("netfilter: conntrack: allow insertion of clashing
entries"). Instead of fixing the nfqueue based logic, lets remove it
and let conntrack core handle this instead.
Retain the ->update hook for sake of nfqueue based conntrack helpers.
We could axe this hook completely but we'd have to split confirm and
helper logic again, see commit ee04805ff5 ("netfilter: conntrack: make
conntrack userspace helpers work again").
This SHOULD NOT be backported to kernels earlier than v5.6; they lack
adequate clash resolution handling.
Patch was originally written by Pablo Neira Ayuso.
Reported-by: Antonio Ojea <aojea@google.com>
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1766
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Antonio Ojea <aojea@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Several ruleset objects are still not using GFP_KERNEL_ACCOUNT for
memory accounting, update them. This includes:
- catchall elements
- compat match large info area
- log prefix
- meta secctx
- numgen counters
- pipapo set backend datastructure
- tunnel private objects
Fixes: 33758c8914 ("memcg: enable accounting for nft objects")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Lockless iteration over hook list is possible from netlink dump path,
use rcu variant to iterate over the hook list as is done with flowtable
hooks.
Fixes: b9703ed44f ("netfilter: nf_tables: support for adding new devices to an existing netdev chain")
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only provide ctnetlink_label_size when it is used,
which is when CONFIG_NF_CONNTRACK_EVENTS is configured.
Flagged by clang-18 W=1 builds as:
.../nf_conntrack_netlink.c:385:19: warning: unused function 'ctnetlink_label_size' [-Wunused-function]
385 | static inline int ctnetlink_label_size(const struct nf_conn *ct)
| ^~~~~~~~~~~~~~~~~~~~
The condition on CONFIG_NF_CONNTRACK_LABELS being removed by
this patch guards compilation of non-trivial implementations
of ctnetlink_dump_labels() and ctnetlink_label_size().
However, this is not necessary as each of these functions
will always return 0 if CONFIG_NF_CONNTRACK_LABELS is not defined
as each function starts with the equivalent of:
struct nf_conn_labels *labels = nf_ct_labels_find(ct);
if (!labels)
return 0;
And nf_ct_labels_find always returns NULL if CONFIG_NF_CONNTRACK_LABELS
is not enabled. So I believe that the compiler optimises the code away
in such cases anyway.
Found by inspection.
Compile tested only.
Originally splitted in two patches, Pablo Neira Ayuso collapsed them and
added Fixes: tag.
Fixes: 0ceabd8387 ("netfilter: ctnetlink: deliver labels to userspace")
Link: https://lore.kernel.org/netfilter-devel/20240909151712.GZ2097826@kernel.org/
Signed-off-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Documentation of list_del_rcu() warns callers to not immediately free
the deleted list item. While it seems not necessary to use the
RCU-variant of list_del() here in the first place, doing so seems to
require calling kfree_rcu() on the deleted item as well.
Fixes: 3f0465a9ef ("netfilter: nf_tables: dynamically allocate hooks per net_device in flowtables")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Some of the functions may be unused (CONFIG_NETFILTER_NETLINK_GLUE_CT=n
and CONFIG_NF_CONNTRACK_EVENTS=n), it prevents kernel builds with clang,
`make W=1` and CONFIG_WERROR=y:
net/netfilter/nf_conntrack_netlink.c:657:22: error: unused function 'ctnetlink_acct_size' [-Werror,-Wunused-function]
657 | static inline size_t ctnetlink_acct_size(const struct nf_conn *ct)
| ^~~~~~~~~~~~~~~~~~~
net/netfilter/nf_conntrack_netlink.c:667:19: error: unused function 'ctnetlink_secctx_size' [-Werror,-Wunused-function]
667 | static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
| ^~~~~~~~~~~~~~~~~~~~~
net/netfilter/nf_conntrack_netlink.c:683:22: error: unused function 'ctnetlink_timestamp_size' [-Werror,-Wunused-function]
683 | static inline size_t ctnetlink_timestamp_size(const struct nf_conn *ct)
| ^~~~~~~~~~~~~~~~~~~~~~~~
Fix this by guarding possible unused functions with ifdeffery.
See also commit 6863f5643d ("kbuild: allow Clang to find unused static
inline functions for W=1 build").
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Given existing entry:
ORIGIN: a:b -> c:d
REPLY: c:d -> a:b
And colliding entry:
ORIGIN: c:d -> a:b
REPLY: a:b -> c:d
The colliding ct (and the associated skb) get dropped on insert.
Permit this by checking if the colliding entry matches the reply
direction.
Happens when both ends send packets at same time, both requests are picked
up as NEW, rather than NEW for the 'first' and 'ESTABLISHED' for the
second packet.
This is an esoteric condition, as ruleset must permit NEW connections
in either direction and both peers must already have a bidirectional
traffic flow at the time conntrack gets enabled.
Allow the 'reverse' skb to pass and assign the existing (clashing)
entry.
While at it, also drop the extra 'dying' check, this is already
tested earlier by the calling function.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
A conntrack entry can be inserted to the connection tracking table if there
is no existing entry with an identical tuple in either direction.
Example:
INITIATOR -> NAT/PAT -> RESPONDER
Initiator passes through NAT/PAT ("us") and SNAT is done (saddr rewrite).
Then, later, NAT/PAT machine itself also wants to connect to RESPONDER.
This will not work if the SNAT done earlier has same IP:PORT source pair.
Conntrack table has:
ORIGINAL: $IP_INITATOR:$SPORT -> $IP_RESPONDER:$DPORT
REPLY: $IP_RESPONDER:$DPORT -> $IP_NAT:$SPORT
and new locally originating connection wants:
ORIGINAL: $IP_NAT:$SPORT -> $IP_RESPONDER:$DPORT
REPLY: $IP_RESPONDER:$DPORT -> $IP_NAT:$SPORT
This is handled by the NAT engine which will do a source port reallocation
for the locally originating connection that is colliding with an existing
tuple by attempting a source port rewrite.
This is done even if this new connection attempt did not go through a
masquerade/snat rule.
There is a rare race condition with connection-less protocols like UDP,
where we do the port reallocation even though its not needed.
This happens when new packets from the same, pre-existing flow are received
in both directions at the exact same time on different CPUs after the
conntrack table was flushed (or conntrack becomes active for first time).
With strict ordering/single cpu, the first packet creates new ct entry and
second packet is resolved as established reply packet.
With parallel processing, both packets are picked up as new and both get
their own ct entry.
In this case, the 'reply' packet (picked up as ORIGINAL) can be mangled by
NAT engine because a port collision is detected.
This change isn't enough to prevent a packet drop later during
nf_conntrack_confirm(), the existing clash resolution strategy will not
detect such reverse clash case. This is resolved by a followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The cgroup_get_from_path() function never returns NULL, it returns error
pointers. Update the error handling to match.
Fixes: 7f3287db65 ("netfilter: nft_socket: make cgroupsv2 matching work with namespaces")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://patch.msgid.link/bbc0c4e0-05cc-4f44-8797-2f4b3920a820@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cross-merge networking fixes after downstream PR.
No conflicts (sort of) and no adjacent changes.
This merge reverts commit b3c9e65eb2 ("net: hsr: remove seqnr_lock")
from net, as it was superseded by
commit 430d67bdcb ("net: hsr: Use the seqnr lock for frames received via interlink port.")
in net-next.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When running in container environmment, /sys/fs/cgroup/ might not be
the real root node of the sk-attached cgroup.
Example:
In container:
% stat /sys//fs/cgroup/
Device: 0,21 Inode: 2214 ..
% stat /sys/fs/cgroup/foo
Device: 0,21 Inode: 2264 ..
The expectation would be for:
nft add rule .. socket cgroupv2 level 1 "foo" counter
to match traffic from a process that got added to "foo" via
"echo $pid > /sys/fs/cgroup/foo/cgroup.procs".
However, 'level 3' is needed to make this work.
Seen from initial namespace, the complete hierarchy is:
% stat /sys/fs/cgroup/system.slice/docker-.../foo
Device: 0,21 Inode: 2264 ..
i.e. hierarchy is
0 1 2 3
/ -> system.slice -> docker-1... -> foo
... but the container doesn't know that its "/" is the "docker-1.."
cgroup. Current code will retrieve the 'system.slice' cgroup node
and store its kn->id in the destination register, so compare with
2264 ("foo" cgroup id) will not match.
Fetch "/" cgroup from ->init() and add its level to the level we try to
extract. cgroup root-level is 0 for the init-namespace or the level
of the ancestor that is exposed as the cgroup root inside the container.
In the above case, cgrp->level of "/" resolved in the container is 2
(docker-1...scope/) and request for 'level 1' will get adjusted
to fetch the actual level (3).
v2: use CONFIG_SOCK_CGROUP_DATA, eval function depends on it.
(kernel test robot)
Cc: cgroups@vger.kernel.org
Fixes: e0bb96db96 ("netfilter: nft_socket: add support for cgroupsv2")
Reported-by: Nadia Pinaeva <n.m.pinaeva@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We must put 'sk' reference before returning.
Fixes: 039b1f4f24 ("netfilter: nft_socket: fix erroneous socket assignment")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Unmask the upper DSCP bits when calling nf_route() which eventually
calls ip_route_output_key() so that in the future it could perform the
FIB lookup according to the full DSCP value.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Merge tag 'nf-next-24-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next:
Patch #1 adds ctnetlink support for kernel side filtering for
deletions, from Changliang Wu.
Patch #2 updates nft_counter support to Use u64_stats_t,
from Sebastian Andrzej Siewior.
Patch #3 uses kmemdup_array() in all xtables frontends,
from Yan Zhen.
Patch #4 is a oneliner to use ERR_CAST() in nf_conntrack instead
opencoded casting, from Shen Lichuan.
Patch #5 removes unused argument in nftables .validate interface,
from Florian Westphal.
Patch #6 is a oneliner to correct a typo in nftables kdoc,
from Simon Horman.
Patch #7 fixes missing kdoc in nftables, also from Simon.
Patch #8 updates nftables to handle timeout less than CONFIG_HZ.
Patch #9 rejects element expiration if timeout is zero,
otherwise it is silently ignored.
Patch #10 disallows element expiration larger than timeout.
Patch #11 removes unnecessary READ_ONCE annotation while mutex is held.
Patch #12 adds missing READ_ONCE/WRITE_ONCE annotation in dynset.
Patch #13 annotates data-races around element expiration.
Patch #14 allocates timeout and expiration in one single set element
extension, they are tighly couple, no reason to keep them
separated anymore.
Patch #15 updates nftables to interpret zero timeout element as never
times out. Note that it is already possible to declare sets
with elements that never time out but this generalizes to all
kind of set with timeouts.
Patch #16 supports for element timeout and expiration updates.
* tag 'nf-next-24-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_tables: set element timeout update support
netfilter: nf_tables: zero timeout means element never times out
netfilter: nf_tables: consolidate timeout extension for elements
netfilter: nf_tables: annotate data-races around element expiration
netfilter: nft_dynset: annotate data-races around set timeout
netfilter: nf_tables: remove annotation to access set timeout while holding lock
netfilter: nf_tables: reject expiration higher than timeout
netfilter: nf_tables: reject element expiration with no timeout
netfilter: nf_tables: elements with timeout below CONFIG_HZ never expire
netfilter: nf_tables: Add missing Kernel doc
netfilter: nf_tables: Correct spelling in nf_tables.h
netfilter: nf_tables: drop unused 3rd argument from validate callback ops
netfilter: conntrack: Convert to use ERR_CAST()
netfilter: Use kmemdup_array instead of kmemdup for multiple allocation
netfilter: nft_counter: Use u64_stats_t for statistic.
netfilter: ctnetlink: support CTA_FILTER for flush
====================
Link: https://patch.msgid.link/20240905232920.5481-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
list_head can be initialized automatically with LIST_HEAD()
instead of calling INIT_LIST_HEAD(). Here we can simplify
the code.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://patch.msgid.link/20240904093243.3345012-4-lihongbo22@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Store new timeout and expiration in transaction object, use them to
update elements from .commit path. Otherwise, discard update if .abort
path is exercised.
Use update_flags in the transaction to note whether the timeout,
expiration, or both need to be updated.
Annotate access to timeout extension now that it can be updated while
lockless read access is possible.
Reject timeout updates on elements with no timeout extension.
Element transaction remains in the 96 bytes kmalloc slab on x86_64 after
this update.
This patch requires ("netfilter: nf_tables: use timestamp to check for
set element timeout") to make sure an element does not expire while
transaction is ongoing.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch uses zero as timeout marker for those elements that never expire
when the element is created.
If userspace provides no timeout for an element, then the default set
timeout applies. However, if no default set timeout is specified and
timeout flag is set on, then timeout extension is allocated and timeout
is set to zero to allow for future updates.
Use of zero a never timeout marker has been suggested by Phil Sutter.
Note that, in older kernels, it is already possible to define elements
that never expire by declaring a set with the set timeout flag set on
and no global set timeout, in this case, new element with no explicit
timeout never expire do not allocate the timeout extension, hence, they
never expire. This approach makes it complicated to accomodate element
timeout update, because element extensions do not support reallocations.
Therefore, allocate the timeout extension and use the new marker for
this case, but do not expose it to userspace to retain backward
compatibility in the set listing.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Expiration and timeout are stored in separated set element extensions,
but they are tightly coupled. Consolidate them in a single extension to
simplify and prepare for set element updates.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
element expiration can be read-write locklessly, it can be written by
dynset and read from netlink dump, add annotation.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
set timeout can be read locklessly while being updated from control
plane, add annotation.
Fixes: 123b99619c ("netfilter: nf_tables: honor set timeout and garbage collection updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Mutex is held when adding an element, no need for READ_ONCE, remove it.
Fixes: 123b99619c ("netfilter: nf_tables: honor set timeout and garbage collection updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Report ERANGE to userspace if user specifies an expiration larger than
the timeout.
Fixes: 8e1102d5a1 ("netfilter: nf_tables: support timeouts larger than 23 days")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If element timeout is unset and set provides no default timeout, the
element expiration is silently ignored, reject this instead to let user
know this is unsupported.
Also prepare for supporting timeout that never expire, where zero
timeout and expiration must be also rejected.
Fixes: 8e1102d5a1 ("netfilter: nf_tables: support timeouts larger than 23 days")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Element timeout that is below CONFIG_HZ never expires because the
timeout extension is not allocated given that nf_msecs_to_jiffies64()
returns 0. Set timeout to the minimum value to honor timeout.
Fixes: 8e1102d5a1 ("netfilter: nf_tables: support timeouts larger than 23 days")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use the ERR_CAST macro to clearly indicate that this is a pointer
to an error value and that a type conversion was performed.
Signed-off-by: Shen Lichuan <shenlichuan@vivo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When we are allocating an array, using kmemdup_array() to take care about
multiplication and possible overflows.
Also it makes auditing the code easier.
Signed-off-by: Yan Zhen <yanzhen@vivo.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The nft_counter uses two s64 counters for statistics. Those two are
protected by a seqcount to ensure that the 64bit variable is always
properly seen during updates even on 32bit architectures where the store
is performed by two writes. A side effect is that the two counter (bytes
and packet) are written and read together in the same window.
This can be replaced with u64_stats_t. write_seqcount_begin()/ end() is
replaced with u64_stats_update_begin()/ end() and behaves the same way
as with seqcount_t on 32bit architectures. Additionally there is a
preempt_disable on PREEMPT_RT to ensure that a reader does not preempt a
writer.
On 64bit architectures the macros are removed and the reads happen
without any retries. This also means that the reader can observe one
counter (bytes) from before the update and the other counter (packets)
but that is okay since there is no requirement to have both counter from
the same update window.
Convert the statistic to u64_stats_t. There is one optimisation:
nft_counter_do_init() and nft_counter_clone() allocate a new per-CPU
counter and assign a value to it. During this assignment preemption is
disabled which is not needed because the counter is not yet exposed to
the system so there can not be another writer or reader. Therefore
disabling preemption is omitted and raw_cpu_ptr() is used to obtain a
pointer to a counter for the assignment.
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
From cb8aa9a, we can use kernel side filtering for dump, but
this capability is not available for flush.
This Patch allows advanced filter with CTA_FILTER for flush
Performace
1048576 ct flows in total, delete 50,000 flows by origin src ip
3.06s -> dump all, compare and delete
584ms -> directly flush with filter
Signed-off-by: Changliang Wu <changliang.wu@smartx.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Merge tag 'nf-next-24-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following batch contains Netfilter updates for net-next:
Patch #1 fix checksum calculation in nfnetlink_queue with SCTP,
segment GSO packet since skb_zerocopy() does not support
GSO_BY_FRAGS, from Antonio Ojea.
Patch #2 extend nfnetlink_queue coverage to handle SCTP packets,
from Antonio Ojea.
Patch #3 uses consume_skb() instead of kfree_skb() in nfnetlink,
from Donald Hunter.
Patch #4 adds a dedicate commit list for sets to speed up
intra-transaction lookups, from Florian Westphal.
Patch #5 skips removal of element from abort path for the pipapo
backend, ditching the shadow copy of this datastructure
is sufficient.
Patch #6 moves nf_ct_netns_get() out of nf_conncount_init() to
let users of conncoiunt decide when to enable conntrack,
this is needed by openvswitch, from Xin Long.
Patch #7 pass context to all nft_parse_register_load() in
preparation for the next patch.
Patches #8 and #9 reject loads from uninitialized registers from
control plane to remove register initialization from
datapath. From Florian Westphal.
* tag 'nf-next-24-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_tables: don't initialize registers in nft_do_chain()
netfilter: nf_tables: allow loads only when register is initialized
netfilter: nf_tables: pass context structure to nft_parse_register_load
netfilter: move nf_ct_netns_get out of nf_conncount_init
netfilter: nf_tables: do not remove elements if set backend implements .abort
netfilter: nf_tables: store new sets in dedicated list
netfilter: nfnetlink: convert kfree_skb to consume_skb
selftests: netfilter: nft_queue.sh: sctp coverage
netfilter: nfnetlink_queue: unbreak SCTP traffic
====================
Link: https://patch.msgid.link/20240822221939.157858-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ensure there is sufficient room to access the protocol field of the
VLAN header, validate it once before the flowtable lookup.
=====================================================
BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32
nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline]
nf_ingress net/core/dev.c:5440 [inline]
Fixes: 4cd91f7c29 ("netfilter: flowtable: add vlan support")
Reported-by: syzbot+8407d9bb88cd4c6bf61a@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
revert commit 4c905f6740 ("netfilter: nf_tables: initialize registers in
nft_do_chain()").
Previous patch makes sure that loads from uninitialized registers are
detected from the control plane. in this case rule blob auto-zeroes
registers. Thus the explicit zeroing is not needed anymore.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reject rules where a load occurs from a register that has not seen a store
early in the same rule.
commit 4c905f6740 ("netfilter: nf_tables: initialize registers in
nft_do_chain()")
had to add a unconditional memset to the nftables register space to avoid
leaking stack information to userspace.
This memset shows up in benchmarks. After this change, this commit can
be reverted again.
Note that this breaks userspace compatibility, because theoretically
you can do
rule 1: reg2 := meta load iif, reg2 == 1 jump ...
rule 2: reg2 == 2 jump ... // read access with no store in this rule
... after this change this is rejected.
Neither nftables nor iptables-nft generate such rules, each rule is
always standalone.
This resuts in a small increase of nft_ctx structure by sizeof(long).
To cope with hypothetical rulesets like the example above one could emit
on-demand "reg[x] = 0" store when generating the datapath blob in
nf_tables_commit_chain_prepare().
A patch that does this is linked to below.
For now, lets disable this. In nf_tables, a rule is the smallest
unit that can be replaced from userspace, i.e. a hypothetical ruleset
that relies on earlier initialisations of registers can't be changed
at will as register usage would need to be coordinated.
Link: https://lore.kernel.org/netfilter-devel/20240627135330.17039-4-fw@strlen.de/
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_counter_reset() resets the counter by subtracting the previously
retrieved value from the counter. This is a write operation on the
counter and as such it requires to be performed with a write sequence of
nft_counter_seq to serialize against its possible reader.
Update the packets/ bytes within write-sequence of nft_counter_seq.
Fixes: d84701ecbc ("netfilter: nft_counter: rework atomic dump and reset")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The sequence counter nft_counter_seq is a per-CPU counter. There is no
lock associated with it. nft_counter_do_eval() is using the same counter
and disables BH which suggest that it can be invoked from a softirq.
This in turn means that nft_counter_offload_stats(), which disables only
preemption, can be interrupted by nft_counter_do_eval() leading to two
writer for one seqcount_t.
This can lead to loosing stats or reading statistics while they are
updated.
Disable BH during stats update in nft_counter_offload_stats() to ensure
one writer at a time.
Fixes: b72920f6e4 ("netfilter: nftables: counter hardware offload support")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch is to move nf_ct_netns_get() out of nf_conncount_init()
and let the consumers of nf_conncount decide if they want to turn
on netfilter conntrack.
It makes nf_conncount more flexible to be used in other places and
avoids netfilter conntrack turned on when using it in openvswitch
conntrack.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
pipapo set backend maintains two copies of the datastructure, removing
the elements from the copy that is going to be discarded slows down
the abort path significantly, from several minutes to few seconds after
this patch.
This patch was previously reverted by
f86fb94011 ("netfilter: nf_tables: revert do not remove elements if set backend implements .abort")
but it is now possible since recent work by Florian Westphal to perform
on-demand clone from insert/remove path:
532aec7e87 ("netfilter: nft_set_pipapo: remove dirty flag")
3f1d886cc7 ("netfilter: nft_set_pipapo: move cloning of match info to insert/removal path")
a238106703 ("netfilter: nft_set_pipapo: prepare pipapo_get helper for on-demand clone")
c5444786d0 ("netfilter: nft_set_pipapo: merge deactivate helper into caller")
6c108d9bee ("netfilter: nft_set_pipapo: prepare walk function for on-demand clone")
8b8a241755 ("netfilter: nft_set_pipapo: prepare destroy function for on-demand clone")
80efd2997f ("netfilter: nft_set_pipapo: make pipapo_clone helper return NULL")
a590f47609 ("netfilter: nft_set_pipapo: move prove_locking helper around")
after this series, the clone is fully released once aborted, no need to
take it back to previous state. Thus, no stale reference to elements can
occur.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
