In q2_get_counter(), a new counter entry is added to counter_list
and counter_list_lock is released before proc_create_data() is
invoked. During this window, another thread can locate the counter
in counter_list and increment its reference count via
atomic_inc(&e->ref).
If proc_create_data() subsequently fails, the error handling path
previously called list_del() and kfree() unconditionally, ignoring
the refcount. If another thread acquired a reference in the interim,
this resulted in a Use-After-Free (UAF) condition.
Fix this by using atomic_dec_and_test(&e->ref) under
counter_list_lock when proc_create_data() fails. Only remove from
counter_list and free the memory if the refcount reaches zero. If
another thread holds a reference, set procfs_entry to NULL and
leave the counter intact for the surviving thread.
Fixes: 2e134f75ce91 ("ANDROID: netfilter: xt_quota2: add quota2 from xtables-addons")
Bug: 499166786
Change-Id: I1270d6d94ec0bd6a83858ad053434dae0393b7e3
Signed-off-by: Todd Kjos <tkjos@google.com>
The sysfs_remove_file() call in idletimer_tg_destroy() was incorrectly
placed before cancel_work_sync() during a merge conflict resolution in
commit 92cf99250d ("Merge tag 'v6.2-rc1' into android-mainline").
Let's switch to the original order as introduced by commit 68983a354a
("netfilter: xtables: Add snapshot of hardidletimer target"). This
aligns the order of the calls with upstream.
Also move unregister_pm_notifier() calls before timer_shutdown_sync().
This aligns the order of the calls with older ACK branches. As having
these differences across branches is creating confusion with partners.
Bug: 497588852
Bug: 531493108
Fixes: 92cf99250d ("Merge tag 'v6.2-rc1' into android-mainline")
Change-Id: Ia65db132c22a487b1874e9b59da8e7c9ad3ac324
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Work on removing rtnl_lock protection throughout the stack
continues. In this chapter:
- don't use rtnl_lock for IPv6 multicast routing configuration
- don't take rtnl_lock in ethtool for modern drivers
- prepare Qdisc dump callbacks for rtnl_lock removal
- Support dumping just ifindex + name of all interfaces, under RCU.
It's a common operation for Netlink CLI tools (when translating
names to ifindexes) and previously required full rtnl_lock.
- Support dumping qdiscs and page pools for a specific netdev. Even
tho user space wants a dump of all netdevs, most of the time, the
OOO programming model results in repeating the dump for each
netdev. Which, in absence of a cache, leads to a O(n^2) behavior.
- Flush nexthops once on multi-nexthop removal (e.g. when device goes
down), another O(n^2) -> O(n) improvement.
- Rehash locally generated traffic to a different nexthop on
retransmit timeout.
- Honor oif when choosing nexthop for locally generated IPv6 traffic.
- Convert TCP Auth Option to crypto library, and drop non-RFC algos.
- Increase subflow limits in MPTCP to 64 and endpoint limit to 256.
- Support MPTCP signaling of IPv6 address + port (ADD_ADDR). We need
to selectively skip reporting of the standard TCP Timestamp option,
because they won't fit into the header space together (12 + 30 >
40).
- Support using bridge neighbor suppression, Duplicate Address
Detection, Gratuitous ARP and unsolicited NA forwarding - in EVPN
deployments, e.g. VXLAN fabrics (IPv4 and IPv6).
- Improve link state reporting for upper netdevs (e.g. macvlan) over
tunnel devices (again, mostly for EVPN deployments).
- Support binding GENEVE tunnels to a local address.
- Speed up UDP tunnel destruction (remove one synchronize_rcu()).
- Support exponential field encoding in multicast (IGMPv3 and MLDv2).
- Support attaching PSP crypto offload to containers (veth, netkit).
- Add a new IPSec Netlink message XFRM_MSG_MIGRATE_STATE that allows
migrating individual IPsec SAs independently of their policies.
The existing XFRM_MSG_MIGRATE is tightly coupled to policy+SA
migration, lacks SPI for unique SA identification, and cannot
express reqid changes or migrate Transport mode selectors.
The new interface identifies the SA via SPI and mark, supports
reqid changes, address family changes, encap removal, and uses an
atomic create+install flow under x->lock to prevent SN/IV reuse
during AEAD SA migration.
- Implement GRO/GSO support for PPPoE.
- Convert sockopt callbacks in a number of protocols to iov_iter.
Cross-tree stuff:
- Remove support for Crypto TFM cloning (unblocked after the TCP Auth
Option rework). This feature regressed performance for all crypto
API users, since it changed crypto transformation objects into
reference-counted objects.
- Add FCrypt-PCBC implementation to rxrpc and remove it from the
global crypto API as obsolete and insecure.
Wireless:
- Major rework of station bandwidth handling, fixing issues with
lower capability than AP.
- Cleanups for EMLSR spec issues (drafts differed).
- More Neighbor Awareness Networking (Wi-Fi Aware) work (multicast,
schedule improvements, multi-station etc.)
- Some Ultra High Reliability (UHR) / IEEE 802.11bn (D1.4) work
(e.g. non-primary channel access, UHR DBE support).
- Fine Timing Measurement ranging (i.e. distance measurement) APIs.
Netfilter:
- Use per-rule hash initval in nf_conncount. This avoids unnecessary
lock contention with short keys (e.g. conntrack zones) in different
namespaces.
- Various safety improvements, both in packet parsing and object
lifetimes. Notably add refcounts to conntrack timeout policy.
Deletions:
- Remove TLS + sockmap integration. TLS wants to pin user pages to
avoid a copy, and sockmap wants to write to the input stream. More
work on this integration is clearly needed, and we can't find any
users (original author admitted that they never deployed it).
- Remove support for TLS offload with TCP Offload Engine (the far
more common opportunistic offload is retained). The locking looks
unfixable (driver sleeps under TCP spin locks) and people from the
vendor that added this are AWOL.
- Remove more ATM code, trying to leave behind only what PPPoATM
needs, AAL5 and br2684 with permanent circuits.
- Remove AppleTalk. Let it join hamradio in our out of tree protocol
graveyard, I mean, repository.
- Disable 32-bit x_tables compatibility (32bit binaries on 64bit
kernel) interface in user namespaces. To be deleted completely,
soon.
- Remove 5/10 MHz support from cfg80211/mac80211.
Drivers:
- Software:
- Support DEVMEM/DMABUF Tx over NETMEM_TX_NO_DMA devices (netkit)
- bonding: add knob to strictly follow 802.3ad for link state
- New drivers:
- Alibaba Elastic Ethernet Adaptor (cloud vNIC).
- NXP NETC switch within i.MX94.
- DPLL:
- Add operational state to pins (implement in zl3073x).
- Add generic DPLL type, for daisy-chaining DPLLs (implement in ice).
- Ethernet high-speed NICs:
- Huawei (hinic3):
- enhance tc flow offload support with queue selection,
tunnels
- nVidia/Mellanox:
- avoid over-copying payload to the skb's linear part (up to
60% win for LRO on slow CPUs like ARM64 V2)
- expose more per-queue stats over the standard API
- support additional, unprivileged PFs in the DPU
configuration
- support Socket Direct (multi-PF) with switchdev offloads
- add a pool / frag allocator for DMA mapped buffers for
control objects, save memory on systems with 64kB page size
- take advantage of the ability to dynamically change RSS
table size, even when table is configured by the user
- increase the max RSS table size for even traffic
distribution
- Ethernet NICs:
- Marvell/Aquantia:
- AQC113 PTP support
- Realtek USB (r8152):
- support 10Gbit Link Speeds and Energy-Efficient Ethernet
(EEE)
- support firmware loaded (for RTL8157/RTL8159)
- support for the RTL8159
- Intel (ixgbe):
- support Energy-Efficient Ethernet (EEE) on E610 devices
- Ethernet switches:
- Airoha:
- support multiple netdevs on a single GDM block / port
- Marvell (mv88e6xxx):
- support SERDES of mv88e6321
- Microchip (ksz8/9):
- rework the driver callbacks to remove one indirection layer
- Motorcomm (yt921x):
- support port rate policing
- support TBF qdisc offload
- support ACL/flower offload
- nVidia/Mellanox:
- expose per-PG rx_discards
- Realtek:
- rtl8365mb: bridge offloading and VLAN support
- Ethernet PHYs:
- Airoha:
- support Airoha AN8801R Gigabit PHYs.
- Micrel:
- implement 3 low-loss cable tunables
- Realtek:
- support MDI swapping for RTL8226-CG
- support MDIO for RTL931x
- Qualcomm:
- at803x: Rx and Tx clock management for IPQ5018 PHY
- Motorcomm:
- support YT8522 100M RMII PHY
- set drive strength in YT8531s RGMII
- TI:
- dp83822: add optional external PHY clock
- Bluetooth:
- hci_sync: add support for HCI_LE_Set_Host_Feature [v2]
- SMP: use AES-CMAC library API
- Intel:
- support Product level reset
- support smart trigger dump
- Mediatek:
- add event filter to filter specific event
- Realtek:
- fix RTL8761B/BU broken LE extended scan
- WiFi:
- Broadcom (b43):
- new support for a 11n device
- MediaTek (mt76):
- support mt7927
- mt792x: broken usb transport detection
- mt7921: regulatory improvements
- Qualcomm (ath9k):
- GPIO interface improvements
- Qualcomm (ath12k):
- WDS support
- replace dynamic memory allocation in WMI Rx path
- thermal throttling/cooling device support
- 6 GHz incumbent interference detection
- channel 177 in 5 GHz
- Realtek (rt89):
- RTL8922AU support
- USB 3 mode switch for performance
- better monitor radiotap support
- RTL8922DE preparations"
* tag 'net-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1778 commits)
ipv4: fib_rule: Move fib4_rules_exit() to ->exit().
net: serialize netif_running() check in enqueue_to_backlog()
net: skmsg: preserve sg.copy across SG transforms
appletalk: move the protocol out of tree
appletalk: stop storing per-interface state in struct net_device
selftests/bpf: test that TLS crypto is rejected on a sockmap socket
selftests/bpf: drop the unused kTLS program from test_sockmap
selftests/bpf: remove sockmap + ktls tests
tls: remove dead sockmap (psock) handling from the SW path
tls: reject the combination of TLS and sockmap
atm: remove orphaned uAPI for deleted drivers, protocols and SVCs
atm: remove unused ATM PHY operations
atm: remove the unused pre_send and send_bh device operations
atm: remove the unused change_qos device operation
atm: remove SVC socket support and the signaling daemon interface
atm: remove the local ATM (NSAP) address registry
atm: remove dead SONET PHY ioctls
atm: remove the unused send_oam / push_oam callbacks
atm: remove AAL3/4 transport support
net: dsa: sja1105: fix lastused timestamp in flower stats
...
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next.
More specifically, this contains conncount rework to address AI related
reports, assorted Netfiter updates and two small incremental updates on
IPVS:
1) Replace old obsolete workqueues (system_wq, system_unbound_wq)
in IPVS, from Marco Crivellari.
2) Replace WARN_ON{_ONCE} by DEBUG_NET_WARN_ON_ONCE in nf_tables.
In the recent years, reporters say that the use of WARN_ON{_ONCE}
in conjunction with panic_on_warn=1 results in DoS. Let's replace
it by DEBUG_NET_WARN_ON_ONCE so this is only exercised by test
infrastructure and fuzzers, while also providing context to AI
agents. From Fernando F. Mancera.
Five patches from Florian Westphal to address AI reports in the conncount
infrastructures:
3) Fix missing rcu read lock section when calling
__ovs_ct_limit_get_zone_limit().
4) Add a dedicate lock per rbtree tree, this increases memory
usage but it should improve scalability.
5) Add a helper function to find the rbtree node, no functional
changes are intented.
6) Add sequence counter to detect concurrent tree modifications
and retry lookups.
7) Add locks to GC conncount walk and address other nitpicks.
Then, several assorted updates:
8) Defensive Tree-wide addition of NULL checks for ct extensions.
9) Bail out if flowtable bypass cannot be fully set up from the
flow offload expression, instead of lazy building a likely
incomplete one.
10) Fix documentation for the new conn_max sysctl toggle in IPVS.
11) Add nf_dev_xmit_recursion*() helpers and use them, to address
recent AI reports.
* tag 'nf-next-26-06-14' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them
ipvs: fix doc syntax for conn_max sysctl
netfilter: flowtable: bail out if forward path cannot be discovered
netfilter: conntrack: check NULL when retrieving ct extension
netfilter: nf_conncount: gc and rcu fixes
netfilter: nf_conncount: add sequence counter to detect tree modifications
netfilter: nf_conncount: split count_tree_node rbtree walk into helper
netfilter: nf_conncount: use per nf_conncount_data spinlocks
netfilter: nf_conncount: callers must hold rcu read lock
netfilter: nf_tables: use DEBUG_NET_WARN_ON_ONCE in packet and control paths
ipvs: Replace use of system_unbound_wq with system_dfl_long_wq
====================
Link: https://patch.msgid.link/20260614114605.474783-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull timer core updates from Thomas Gleixner:
"Updates for the time/timer core subsystem:
- Harden the user space controllable hrtimer interfaces further to
protect against unpriviledged DoS attempts by arming timers in the
past.
- Add per-capacity hierarchies to the timer migration code to prevent
timer migration accross different capacity domains. This code has
been disabled last minute as there is a pathological problem with
SoCs which advertise a larger number of capacity domains. The
problem is under investigation and the code won't be active before
v7.3, but that turned out to be less intrusive than a full revert
as it preserves the preparatory steps and allows people to work on
the final resolution
- Export time namespace functionality as a recent user can be built
as a module.
- Initialize the jiffies clocksource before using it. The recent
hardening against time moving backward requires that the related
members of struct clocksource have been initialized, otherwise it
clamps the readout to 0, which makes time stand sill and causes
boot delays.
- Fix a more than twenty year old PID reference count leak in an
error path of the POSIX CPU timer code.
- The usual small fixes, improvements and cleanups all over the
place"
* tag 'timers-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (31 commits)
posix-cpu-timers: Fix pid refcount leak in do_cpu_nanosleep() error path
time/jiffies: Register jiffies clocksource before usage
timers/migration: Temporarily disable per capacity hierarchies
timers/migration: Turn tmigr_hierarchy level_list into a flexible array
timers/migration: Deactivate per-capacity hierarchies under nohz_full
timers/migration: Fix hotplug migrator selection target on asymetric capacity machines
ntsync: Honour caller's time namespace for absolute MONOTONIC timeouts
time/namespace: Export init_time_ns and do_timens_ktime_to_host()
timers/migration: Update stale @online doc to @available
timers: Fix flseep() typo in kernel-doc comment
hrtimer: Fix the bogus return type of __hrtimer_start_range_ns()
hrtimer: Return ktime_t from hrtimer_get_next_event()/hrtimer_next_event_without()
clocksource: Clean up clocksource_update_freq() functions
alarmtimer: Remove stale return description from alarm_handle_timer()
selftests/posix_timers: Use CLOCK_THREAD_CPUTIME_ID for ITIMER_PROF measurements
scripts/timers: Add timer_migration_tree.py
timers/migration: Handle capacity in connect tracepoints
timers/migration: Split per-capacity hierarchies
timers/migration: Track CPUs in a hierarchy
timers/migration: Abstract out hierarchy to prepare for CPU capacity awareness
...
Update nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers.
This patch also disables BH when transmitting the skb to address a
possible migration to different CPU leading to imbalanced decrementation
of the recursion counters.
This is modeled after Florian Westphal's dev_xmit_recursion*() API
available since commit 97cdcf37b5 ("net: place xmit recursion in
softnet data") according to its current state in the tree.
Fixes: 1d47b55b36 ("netfilter: nft_fwd_netdev: use recursion counter in neigh egress path")
Fixes: f37ad91270 ("netfilter: nf_dup_netdev: Move the recursion counter struct netdev_xmit")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If forward path discovery fails for any reason or netdevice is not
registered for this flowtable, then bail out to classic forwarding path
rather than providing incomplete forwarding path.
Update the existing forward path parser functions to report an error
so the flow_offload expressions gives up on setting up the flowtable
entry.
Link: https://sashiko.dev/#/patchset/20260607094954.48892-15-pablo%40netfilter.org?part=14
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_ct_ext_find() might return NULL if ct extension is not found.
Add also the null checks to:
- nfct_help()
- nfct_help_data()
- nfct_seqadj()
- nfct_nat()
This is defensive, for safety reasons.
nf_ct_ext_find() used to return NULL if the extension is stale for
unconfirmed conntracks if the genid validation fails.
Skip NULL check in nf_nat_inet_fn() given this is valid to be NULL
for non-initialized ct nat extensions.
While at it, fetch ct helper area in nf_ct_expect_related_report() only
once and pass it on to other ancilliary functions. Replace WARN_ON()
by WARN_ON_ONCE() in nf_ct_unlink_expect_report().
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Another drive-by AI review:
1) tree_gc_worker fails to wrap around after it can't find more pending
work. Update data->gc_tree unconditionally. If its 0, start from
the first pending tree (which can be 0).
2) tree_gc_worker() iterates the rbtree without lock. This is never
safe. Move iteration under the spinlock. If this takes too long
(resched needed), save key of next node, drop lock, resched, re-lock,
then search for the key (node). In very rare cases this node might
no longer exist, in that case we can just wait for next gc.
3) use disable_work_sync(), we don't want any restarts.
4) module exit function needs rcu_barrier before we zap the kmem cache.
Fixes: 5c789e131c ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Closes: https://sashiko.dev/#/patchset/20260525182924.28456-1-fw%40strlen.de
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
There a two issues with traversal:
1. Key lookup (tree search) cannot detect concurrent modifications and may
not find a result in case of parallel modification.
2. Worker does a lockless iteration. This is never safe.
Add a sequence counter and re-do the lookup under lock in case the
tree was modified / seqcount changed.
gc_worker bugs are addressed in the next patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add find_tree_node() helper that fetches a matching rbtree node.
This is used by followup patch to optionally search the tree again while
preventing concurrent updates via tree lock.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This change replaces the rb_root with a new container structure.
Instead of an array of locks shared by all nf_conncount_data objects,
each tree gains its own dedicated lock.
Downside: nf_conncount_data increases in size. Before this change:
struct nf_conncount_data {
[..]
/* --- cacheline 33 boundary (2112 bytes) was 16 bytes ago --- */
unsigned int gc_tree; /* 2128 4 */
/* size: 2136, cachelines: 34, members: 7 */
/* padding: 4 */
After:
/* size: 4184, cachelines: 66, members: 7 */
/* padding: 4 */
On LOCKDEP enabled kernels, this is even worse:
/* size: 18560, cachelines: 290, members: 7 */
(due to lockdep map in each spinlock).
For this reason also switch to kvzalloc. The zeroing variant is needed
to not start with random (heap memory content) in the ->pending_trees
bitmap.
Followup patch will add and use a sequence counter.
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
rcu_derefence_raw() should not have been used here, it concealed this bug.
Its used because struct rb_node lacks __rcu annotated pointers, so plain
rcu_derefence causes sparse warnings.
The major tradeoff is that rcu_derefence_raw() doesn't warn when the caller
isn't in a rcu read section.
Extend the rcu read lock scope accordingly and cause sparse warnings,
those warnings are the lesser evil.
Fixes: 11efd5cb04 ("openvswitch: Support conntrack zone limit")
Closes: https://sashiko.dev/#/patchset/20260603230610.7900-1-fw%40strlen.de
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace raw warning macros with DEBUG_NET_WARN_ON_ONCE across the
nf_tables API, core engine, and expression evaluations. This prevents
unnecessary system panics when panic_on_warn=1 is enabled in production
systems.
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch continues the effort to refactor workqueue APIs, which has
begun with the changes introducing new workqueues and a new
alloc_workqueue flag:
commit 128ea9f6cc ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566 ("workqueue: Add new WQ_PERCPU flag")
The point of the refactoring is to eventually alter the default behavior
of workqueues to become unbound by default so that their workload
placement is optimized by the scheduler.
Before that to happen, workqueue users must be converted to the better
named new workqueues with no intended behaviour changes:
system_wq -> system_percpu_wq
system_unbound_wq -> system_dfl_wq
This way the old obsolete workqueues (system_wq, system_unbound_wq) can
be removed in the future.
This specific work is considered long, so enqueue it using
system_dfl_long_wq instead of system_dfl_wq.
Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cross-merge networking fixes after downstream PR (net-7.1-rc8).
Conflicts:
drivers/net/ethernet/wangxun/txgbe/txgbe_aml.c
f67aead16e ("net: txgbe: rework service event handling")
57d39faed4 ("net: txgbe: improve functions of AML 40G devices")
net/rds/info.c
512db8267b ("rds: mark snapshot pages dirty in rds_info_getsockopt()")
6e94eeb2a2 ("rds: convert to getsockopt_iter")
Adjacent changes:
include/net/sock.h
1ee90b77b7 ("net: guard timestamp cmsgs to real error queue skbs")
f0de88303d ("net: make is_skb_wmem() available to modules")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
For NFT_FIB_RESULT_OIFNAME the destination register is declared with
len = IFNAMSIZ (four 32-bit registers), but on the lookup-fail,
RTN_LOCAL and oif-mismatch paths nft_fib{4,6}_eval() only writes one
register via "*dest = 0". The remaining three registers are left as
whatever was on the stack in nft_do_chain()'s struct nft_regs, and a
downstream expression that loads the register span can leak that
uninitialised kernel stack to userspace.
The NFTA_FIB_F_PRESENT existence check has the same shape: it is only
meaningful for NFT_FIB_RESULT_OIF, yet it was accepted for any result type
while the eval stores a single byte via nft_reg_store8(), leaving the rest
of the declared span stale.
Fix both:
- replace the bare "*dest = 0" in the eval with nft_fib_store_result(),
which strscpy_pad()s the whole IFNAMSIZ for OIFNAME (and is already
used on the other early-return path), and
- restrict NFTA_FIB_F_PRESENT to NFT_FIB_RESULT_OIF and declare its
destination as a single u8, so the marked span matches the one byte
the eval writes.
Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Suggested-by: Florian Westphal <fw@strlen.de>
Cc: stable@vger.kernel.org
Signed-off-by: Davide Ornaghi <d.ornaghi97@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_exthdr_init() passes user-controlled priv->len to
nft_parse_register_store(), which marks that many bytes in the
register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT
is set, the eval paths write only 1 byte (nft_reg_store8) or
4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4,
registers beyond the first are never written, retaining
uninitialized stack data from nft_regs.
Bail out if userspace requests too much data when F_PRESENT is set.
Reported-by: Ji'an Zhou <eilaimemedsnaimel@gmail.com>
Fixes: c078ca3b0c ("netfilter: nft_exthdr: Add support for existence check")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The fallback path of dump_mac_header() guards the MAC header access
only with "skb->mac_header != skb->network_header", without checking
skb_mac_header_was_set(). When the MAC header is unset, mac_header is
0xffff, so the test passes and skb_mac_header(skb) returns
skb->head + 0xffff, ~64 KiB past the buffer; the loop then reads
dev->hard_header_len bytes out of bounds into the kernel log.
This is reachable via the netdev logger: nf_log_unknown_packet() calls
dump_mac_header() unconditionally, and an skb sent through AF_PACKET
with PACKET_QDISC_BYPASS reaches the egress hook with mac_header still
unset (__dev_queue_xmit(), which would reset it, is bypassed).
Add the skb_mac_header_was_set() check the ARPHRD_ETHER path already
uses, and replace the open-coded MAC header length test with
skb_mac_header_len(). Only skbs with an unset MAC header are affected;
valid ones are dumped as before.
BUG: KASAN: slab-out-of-bounds in dump_mac_header (net/netfilter/nf_log_syslog.c:831)
Read of size 1 at addr ffff88800ea49d3f by task exploit/148
Call Trace:
kasan_report (mm/kasan/report.c:595)
dump_mac_header (net/netfilter/nf_log_syslog.c:831)
nf_log_netdev_packet (net/netfilter/nf_log_syslog.c:938 net/netfilter/nf_log_syslog.c:963)
nf_log_packet (net/netfilter/nf_log.c:260)
nft_log_eval (net/netfilter/nft_log.c:60)
nft_do_chain (net/netfilter/nf_tables_core.c:285)
nft_do_chain_netdev (net/netfilter/nft_chain_filter.c:307)
nf_hook_slow (net/netfilter/core.c:619)
nf_hook_direct_egress (net/packet/af_packet.c:257)
packet_xmit (net/packet/af_packet.c:280)
packet_sendmsg (net/packet/af_packet.c:3114)
__sys_sendto (net/socket.c:2265)
Fixes: 7eb9282cd0 ("netfilter: ipt_LOG/ip6t_LOG: add option to print decoded MAC header")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
NAT helpers such as nf_nat_h323 store a raw pointer to module text in
exp->expectfn (e.g. ip_nat_q931_expect). nf_ct_helper_expectfn_unregister()
only unlinks the callback descriptor and never walks the expectation table,
so an expectation pending at module removal survives with a dangling
exp->expectfn into freed module text.
When the expected connection arrives, init_conntrack() invokes
exp->expectfn(), now a stale pointer into the unloaded module. Reproduced
on a KASAN build by loading the H.323 helpers, creating a Q.931
expectation, unloading nf_nat_h323, then connecting to the expected port:
Oops: int3: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:0xffffffffa06102d1
init_conntrack.isra.0 (net/netfilter/nf_conntrack_core.c:1862)
nf_conntrack_in (net/netfilter/nf_conntrack_core.c:2049)
ipv4_conntrack_local (net/netfilter/nf_conntrack_proto.c:223)
nf_hook_slow (net/netfilter/core.c:619)
__ip_local_out (net/ipv4/ip_output.c:120)
__tcp_transmit_skb (net/ipv4/tcp_output.c:1715)
tcp_connect (net/ipv4/tcp_output.c:4374)
tcp_v4_connect (net/ipv4/tcp_ipv4.c:345)
__sys_connect (net/socket.c:2167)
Modules linked in: nf_conntrack_h323 [last unloaded: nf_nat_h323]
Reaching the dangling state requires CAP_SYS_MODULE in the initial user
namespace to remove a NAT helper that still has live expectations, so this
is a robustness fix; leaving an expectation pointing at freed text is wrong
regardless.
Add nf_ct_helper_expectfn_destroy(), which walks the expectation table and
drops every expectation whose ->expectfn matches the descriptor being torn
down. Call it from each NAT helper's exit path after the existing RCU grace
period, so no expectation outlives the code it points at and no extra
synchronize_rcu() is introduced. With the fix, the same reproducer runs to
completion without the Oops.
Fixes: f587de0e2f ("[NETFILTER]: nf_conntrack/nf_nat: add H.323 helper port")
Reported-by: Xiang Mei <xmei5@asu.edu>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reported by sashiko:
If nft_flow_action_entry_next() returns NULL, dev reference leaks.
Fixes: c6f8557758 ("netfilter: nf_tables_offload: add nft_flow_action_entry_next() and use it")
Reported-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ebt_redirect_tg() dereferences br_port_get_rcu() return without a
NULL check, causing a kernel panic when the bridge port has been
removed between the original hook invocation and an NFQUEUE
reinject.
A mere NULL check isn't sufficient, however. As sashiko review
points out userspace can not only remove the port from the bridge,
it could also place the device in a different virtual device, e.g.
macvlan.
If this happens, we must drop the packet, there is no way for us to
reinject it into the bridge path.
Switch to _upper API, we don't need the bridge port structure.
Also, this fix keeps another bug intact:
Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER
too aggressive, which prevents certain logging features when queueing
in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old
CONFIG_BRIDGE_NETFILTER cruft is off.
Fixes tag is a common ancestor, this was always broken.
Fixes: f350a0a873 ("bridge: use rx_handler_data pointer to store net_bridge_port pointer")
Reported-by: Ji'an Zhou <eilaimemedsnaimel@gmail.com>
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The timestamp-only fast path dereferences the option stream as
*(__be32 *)ptr, which assumes 4-byte alignment that the TCP option
stream does not guarantee. Use get_unaligned_be32() instead, which
reads the value safely and already returns host byte order, so the
htonl() on the comparison constant can be dropped.
This matches the existing get_unaligned_be32() use later in the same
function.
Assisted-by: Claude:Opus-4.7
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The DEV_PATH_BR_VLAN_UNTAG case post-decrements info->num_encaps
inside WARN_ON_ONCE(). num_encaps is u8, so if it's already 0 the
decrement still happens and wraps it to 255. The break only leaves
the inner switch -- a later path entry can set info->indev back to
a real device, and we end up returning with num_encaps == 255.
nft_dev_forward_path() then walks info.encap[] (size 2) up to
num_encaps, which means an OOB stack read and a bogus count copied
into the route descriptor.
Should only happen on a malformed bridge path stack, hence the WARN,
but worth handling sanely. Move the decrement out of the WARN.
[ While at this, remove the WARN_ON_ONCE since this can only happen
with a buggy bridge path stack --pablo ].
Fixes: e990cef651 ("netfilter: flowtable: add bridge vlan filtering support")
Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For GRE flows, validate that the ct master helper (if any) is pptp
before calling nf_ct_gre_keymap_destroy(), so the helper data area
can be accessed safely. Note that only the pptp helper provides a
.destroy callback.
Fixes: e56894356f ("netfilter: conntrack: remove l4proto destroy hook")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This infrastructure is not used anymore after moving ct timeout and
helper to use datapath refcount to track object use.
Revert commit c56716c69c ("netfilter: extensions: introduce extension
genid count") this patch disables all ct extensions (leading to NULL)
for unconfirmed conntracks, when this is only targeted at ct helper and
ct timeout. There is also codebase that dereferences the ct extension
without checking for NULL which could lead to crash.
Fixes: c56716c69c ("netfilter: extensions: introduce extension genid count")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a new ->ct_refcnt field to struct nf_conntrack_helper
which is bumped when the helper is used by the ct helper extension. Drop
this reference count when the conntrack entry is released. This is a
packet path refcount which ensures that struct nf_conntrack_helper
remains in place for tricky scenarios where a packet sits in nfqueue, or
elsewhere, with a conntrack that refers to this helper.
For simplicity, this leaves a single refcount for helper objects in
place, remove the existing refcount for control plane that ensures that
the helper does not go away if it is used by ruleset.
On helper removal, the help callback is set to NULL to disable it from
packet path and, after rcu grace period, existing expectations are
removed. Update ctnetlink to disable access to .to_nlattr and
.from_nlattr if the helper is going away.
Remove nf_queue_nf_hook_drop() since it has proven not to be effective
because packets with unconfirmed conntracks which are still flying to
sit in nfqueue.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Move the GRE specific cleanup to nf_conntrack_proto_gre.c to ensure that
the .destroy callback for the pptp helper is still reachable by existing
conntrack entries while pptp module is being removed.
This is a preparation patch, no functional changes are intended.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Adapt all existing helpers to use a modified version of
nf_ct_helper_init(), to dynamically allocate struct nf_conntrack_helper.
Allocate expect_policy[] built-in into the helper to ensure this area is
reachable after helper removal since a follow up patch adds refcount to
track use of the nf_conntrack_helper structure from packet path so it
remains around until last reference from ct helper extension is dropped.
Export __nf_conntrack_helper_register() which allows to register
nfnetlink_cthelper dynamically allocated helper. Adapt nfnetlink_cthelper
to use the built-in expect_policy[].
This is a preparation patch to add packet path refcounting to helpers.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a refcount for struct nf_ct_timeout which is used by ct extension to
set the custom ct timeout policy, this tells us that the ct timeout is
being used by a conntrack entry. When the last conntrack entry drops the
refcount on the ct timeout, the ct timeout is released.
Remove the refcount for control plane which controls if the ruleset
refers to the timeout policy. After this update, it is possible to
remove the ct timeout policy from nfnetlink_cttimeout immediately.
This is for simplicity not to handle two refcounts on a single object.
Remove nf_queue_nf_hook_drop(): a packet sitting in nfqueue will just
hold a reference to the nf_ct_timeout object until packet is reinjected,
since this is part of the ct extension, this will be released by the
time the conntrack is freed.
nf_ct_untimeout() is still called to clean up in a best effort basis:
the ct timeout on existing entries gets removed when the ct timeout goes
away, but as long as the iptables ruleset still refers to the ct timeout
through a template, new conntracks may keep attaching it and extend its
lifetime until the rule is removed.
nf_ct_untimeout() is not called anymore from module removal path, this
is unlikely to find timeouts give module refcount is bumped, and the new
refcount already tracks the ct timeout policy use so it is released when
unused.
Fixes: 5097846230 ("netfilter: add cttimeout infrastructure for fine timeout tuning")
Fixes: 7e0b2b57f0 ("netfilter: nft_ct: add ct timeout support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_ct_seqadj_init() is called without holding the ct lock. This can race
with nf_ct_seq_adjust() when a connection is in CLOSE state due to an
RST or connection reopening. In addition for SYN_RECV state, concurrent
processing of packets can trigger nf_ct_seq_adjust() too. These
situations create a read/write data race.
As synproxy is the only user of nf_ct_seqadj_init() at the moment, fix
this by holding ct->lock inside nf_ct_seqadj_init() until all is done.
Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use get_unaligned_be32() and put_unaligned_be32() to safely read and
write the timestamp fields. This prevents performance degradation due to
unaligned memory access or even a crash on strict alignment
architectures.
This follows the implementation of timestamp parsing in the networking
stack at tcp_parse_options() and synproxy_parse_options().
Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
RFC 9293 does not mention anything about duplicated options and each
networking stack handles it in their own way. Currently, Linux kernel is
processing options sequentially and in case of duplicated timestamp
options, the value from the latest one overrides the others.
As SYNPROXY is modifying only the first timestamp option found, a packet
can reach the backend server and it might parse the wrong timestamp
value. Let's just continue parsing the following options and in case a
duplicated timestamp is found, adjust it too.
Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If a packet was malformed or if skb_ensure_writable() failed, the
synproxy_tstamp_adjust() function returned 0 indicating an error but it
was ignored on the callers.
Make the function return a boolean instead to clarify the result and
drop the packet if synproxy_tstamp_adjust() failed due to ENOMEM from
skb_ensure_writable(). In addition, if there are malformed options, skip
the tstamp update but do not drop the packet as that should be done by
the policy directly.
Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conntrack helper flags are accessed from packet and netlink dump path.
Concurrent update of userspace helper flags is not possible, because the
nfnl_mutex in held on updates. These flags are only used by userspace
helpers. Use {READ,WRITE}_ONCE() to access this flags from lockless
paths.
Fixes: 12f7a50533 ("netfilter: add user-space connection tracking helper infrastructure")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The MSS calculation in nf_osf_match_one() manually shifts bytes to
construct a 16-bit value before passing it to ntohs().
This works on little-endian hosts but it does not work on big-endian as
the bytes are being always shifted and set in the same way for all
architectures.
Use get_unaligned_be16() to fix this on big-endian systems. It also
simplifies the code.
Fixes: 11eeef41d5 ("netfilter: passive OS fingerprint xtables match")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
64bit byteorder conversion is broken when several registers need to be
converted because the source register array advances in steps for 4 bytes
instead of 8:
for (i = ...
src64 = nft_reg_load64(&src[i]);
~~~~~ u32 *src
nft_reg_store64(&dst64[i],
Remove the multi-register support, it has other issues as well:
Pablo points out that commit
caf3ef7468 ("netfilter: nf_tables: prevent OOB access in nft_byteorder_eval")
alters semantics: before the loop operated on registers, i.e.
for ( ... )
dst32[i] = htons((u16)src32[i])
.. but after the patch it will operate on bytes, which makes this
useless to convert e.g. concatenations, which store each compound
in its own register.
Multi-convert of u32 has one theoretical application:
ct mark . meta mark . tcp dport @intervalset
Because ct mark and meta mark are host byte order, use with
intervals has to convert the byteorder for ct/meta mark value
to network byte order (bigendian).
nftables emits this:
[ meta load mark => reg 1 ]
[ byteorder reg 1 = hton(reg 1, 4, 4) ]
[ ct load mark => reg 9 ]
[ byteorder reg 9 = hton(reg 9, 4, 4) ]
...
I.e. two separate calls. Theoretically it could be changed to do:
[ meta load mark => reg 1 ]
[ ct load mark => reg 9 ]
[ byteorder reg 1 = htonl(reg 1, 4, 8) ]
...
But then all it would take to change the set to
meta mark . tcp dport . ct mark
... and we'd be back to two "byteorder" calls. IOW, support to
convert a range of registers is both dysfunctional and dubious.
Simplify this: remove the feature.
Pablo Neira Ayuso points out that nftables before 1.1.0 can generate
incorrect byteorder conversions, see 9fe58952c45a,
"evaluate: skip byteorder conversion for selector smaller than 2 bytes"
in nftables.git). Affected rulesets fail to load with this change and
old userspace due to 'len != size' check.
Fixes: c301f0981f ("netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()")
Cc: <stable+noautosel@kernel.org> # may break rule load with old nftables versions
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Link: https://lore.kernel.org/netfilter-devel/20240206104336.ctigqpkunom2ufmn@lion.mk-sys.cz/
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
I noticed this issue while looking at a historic syzbot report [1].
A rule like the one below is enough to trigger the bug:
table ip t {
chain pre {
type filter hook prerouting priority raw;
ct zone set 1
ct original saddr 1.2.3.4 accept
}
}
The first expression attaches a per-cpu template ct via
nft_ct_set_zone_eval() (nf_ct_tmpl_alloc -> kzalloc, tuple is all
zero, nf_ct_l3num(ct) == 0). The next expression then calls
nft_ct_get_eval() on the same skb, treats the template as a real ct
and hits the 16-byte memcpy path. With dreg at NFT_REG32_15 this
overflows past struct nft_regs on the kernel stack; with smaller
dreg values it silently clobbers adjacent registers.
Reject template ct at the eval entry and in nft_ct_get_fast_eval(),
mirroring the check nft_ct_set_eval() already has. Additionally,
bound the address copy in NFT_CT_SRC / NFT_CT_DST by priv->len
instead of by nf_ct_l3num(ct): nf_ct_get_tuple() zeroes the tuple
before pkt_to_tuple() fills in only the protocol-relevant leading
bytes, so the trailing bytes of tuple->{src,dst}.u3.all are
well-defined zero. priv->len is validated at rule load, so the
copy size is now bounded by the destination register rather than
by an untrusted field on the conntrack.
[1]: https://syzkaller.appspot.com/bug?id=389cf09cb72926114fce90dc85a2c3231dcb647c
Fixes: 45d9bcda21 ("netfilter: nf_tables: validate len in nft_validate_data_load()")
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_tunnel_obj_destroy() calls metadata_dst_free() which directly
kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets
that took a reference via dst_hold() in nft_tunnel_obj_eval() and
are still queued (e.g. in a netem qdisc) are left with a dangling
pointer. When these packets are eventually dequeued, dst_release()
operates on freed memory.
Replace metadata_dst_free() with dst_release() so the metadata_dst
is freed only after all references are dropped. The dst subsystem
already handles metadata_dst cleanup in dst_destroy() when
DST_METADATA is set.
Fixes: af308b94a2 ("netfilter: nf_tables: add tunnel support")
Cc: stable@vger.kernel.org
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When parsing fails after we've matched the command string we
should bail out instead of trying to match a different command.
This helper should be deprecated, given prevalence of TLS I doubt it has
any relevance in 2026.
Fixes: 869f37d8e4 ("[NETFILTER]: nf_conntrack/nf_nat: add IRC helper port")
Closes: https://sashiko.dev/#/patchset/20260525182924.28456-1-fw%40strlen.de
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Todd Kjos
Carlos Llamas
Linus Torvalds
Jakub Kicinski
Pablo Neira Ayuso
Florian Westphal
Fernando Fernandez Mancera
Marco Crivellari
Davide Ornaghi
Xiang Mei
Weiming Shi
Rosen Penev
David Carlier
Julian Anastasov
Jiayuan Chen
Tristan Madani