On helper registration, the maximum number of expectations cannot go over
NF_CT_EXPECT_MAX_CNT (255), but zero can be specified then
nf_conntrack_expect_max applies. Turn zero into NF_CT_EXPECT_MAX_CNT
otherwise, expectation LRU eviction on insertion is disabled.
Moreover, expand this sanity check all expectation classes.
This max_expecy policy is only tunable since userspace helpers are
available, set Fixes: tag to the commit that adds such infrastructure.
Remove the check for p->max_expected given this field must always
be non-zero after this patch.
Fixes: 12f7a50533 ("netfilter: add user-space connection tracking helper infrastructure")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Userspace passes '5000' in case user asks for 5 seconds.
Allowing for sub-second expectation lifetimes makes sense to me. so
fix up the kernel side instead of munging nft to send a value rounded
up to next second.
Also note that this violates nft convention of passing integers in
network byte order, but we can't change this anymore.
Fixes: 857b46027d ("netfilter: nft_ct: add ct expectations support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Run expectation eviction if no helper is specified to deal with the
nft_ct expectation support.
Cap the maximum expectation limit per master conntrack to
NF_CT_EXPECT_MAX_CNT (255).
Fixes: 857b46027d ("netfilter: nft_ct: add ct expectations support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Store master conntrack tuple in the expectation since exp->master might
refer to a different conntrack when accessed from rcu read side lock
area due to typesafe rcu rules.
Fixes: 02a3231b6d ("netfilter: nf_conntrack_expect: store netns and zone in expectation")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
IRC Direct client-to-client requires plaintext. IRC over TLS should be
preferred, making this helper ineffective. Add a deprecation warning and
update the help text to better reflect that this is needed for the DCC
extension, not IRC itself.
PPTP is esoteric these days and it is the only helper that requires the
destroy callback in the conntrack helper API.
Removal would simplify the conntrack core.
Both helpers are IPv4 only.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This feature allows to reset a helper for an existing conntrack, but it
is not safe. This requires a synchronized_rcu() call after resetting the
helper, which is going to be expensive for a large batch of conntrack
entries. This also needs to call to the .destroy callback to release the
GRE/PPTP mappings to fix it.
This feature antedates the creation of the conntrack-tools and I cannot
find a good use-case for this. Given that I cannot find any user in the
netfilter.org userspace tree, I prefer to remove this feature.
Fixes: c1d10adb4a ("[NETFILTER]: Add ctnetlink port for nf_conntrack")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_synproxy_eval_v4() and nft_synproxy_eval_v6() already take a
whole-object READ_ONCE() snapshot of the shared priv->info state before
building the SYNACK reply, but nft_synproxy_tcp_options() still masks
opts->options with priv->info.options from the live shared object.
When a named synproxy object is updated concurrently with SYN traffic,
the eval path can then mix mss and timestamp handling from the local
snapshot with an options mask taken from a newer configuration, so one
SYNACK no longer reflects a coherent synproxy configuration.
Use info->options so nft_synproxy_tcp_options() stays on the same local
snapshot that the eval path already copied from priv->info.
Fixes: ee394f96ad ("netfilter: nft_synproxy: add synproxy stateful object support")
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add sanity check for iph->ihl field in nf_flow_ip4_tunnel_proto() before
using it to compute the header size, avoiding out-of-bounds access with
malformed IP headers.
While at it, use iph->protocol instead of the hardcoded IPPROTO_IPIP
constant when setting ctx->tun.proto and reference ctx->tun.hdr_size
when updating ctx->offset.
Fixes: ab427db178 ("netfilter: flowtable: Add IPIP rx sw acceleration")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Commit 69894e5b4c ("netfilter: nft_connlimit: update the count if add
was skipped") introduced a regression where packets for valid
connections are dropped when using connlimit for soft-limiting
scenarios.
The issue occurs when a new connection reuses a socket currently in
the TIME_WAIT state. In this scenario, the connection tracking entry
is evaluated as already confirmed. Previously, __nf_conncount_add()
assumed that if a connection was confirmed and did not originate from
the loopback interface, it should skip the addition and return -EEXIST.
Skipping the addition triggers a garbage collection run that cleans up
the TIME_WAIT connection. Consequently, the active connection count
drops to 0, which xt_connlimit mishandles, leading to the false rejection
of the perfectly valid new connection.
Fix this by replacing the interface check with protocol-agnostic state
checks. We now skip the tree insertion and preserve the lockless garbage
collection optimization only if the connection is IPS_ASSURED. This
allows early-confirmed setup packets (such as reused TIME_WAIT sockets
or locally generated SYN-ACKs) to be properly evaluated and counted
without falsely dropping. The goto check_connections path is maintained
to ensure these setup packets are deduplicated correctly.
This has been tested with slowhttptest and HTTP server configured
locally to ensure we are not breaking soft-limiting scenarios for local
or external connections. In addition, it was tested with a OVS zone
limit too.
Fixes: 69894e5b4c ("netfilter: nft_connlimit: update the count if add was skipped")
Reported-by: Alejandro Olivan Alvarez <alejandro.olivan.alvarez@gmail.com>
Closes: https://lore.kernel.org/netfilter-devel/177349610461.3071718.4083978280323144323@eldamar.lan/
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We ran into below KASAN splat, which is mostly uninteresting, beside
for having nf_nat_register_fn() in the call chain as a cause for the
offending access:
==================================================================
BUG: KASAN: slab-out-of-bounds in nf_nat_register_fn+0x5f9/0x640
Read of size 8 at addr ffff890031e54c20 by task iptables/9510
CPU: 0 UID: 0 PID: 9510 Comm: iptables Not tainted 6.18.18-grsec-full-20260320181326 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
[…] dump_stack_lvl+0xee/0x160 ffff88004117eeb8
[…] print_report+0x6e/0x640 ffff88004117eee0
[…] ? __phys_addr+0x8e/0x140 ffff88004117eef0
[…] ? kasan_addr_to_slab+0x51/0xe0 ffff88004117ef08
[…] ? complete_report_info+0xec/0x1c0 ffff88004117ef20
[…] ? nf_nat_register_fn+0x5f9/0x640 ffff88004117ef48
[…] kasan_report+0xbc/0x140 ffff88004117ef50
[…] ? nf_nat_register_fn+0x5f9/0x640 ffff88004117ef90
[…] nf_nat_register_fn+0x5f9/0x640 ffff88004117eff8
[…] ? nf_nat_icmp_reply_translation+0x6e0/0x6e0 ffff88004117f070
[…] nf_tables_register_hook.part.0+0xa0/0x220 ffff88004117f080
[…] nf_tables_addchain.constprop.0+0x1054/0x1fc0 ffff88004117f0b8
[…] ? nft_chain_lookup.part.0+0x4ce/0xac0 ffff88004117f130
[…] ? nf_tables_abort+0x3d80/0x3d80 ffff88004117f190
[…] ? nf_tables_dumpreset_obj+0x100/0x100 ffff88004117f1c8
[…] ? nft_table_lookup.part.0+0x255/0x300 ffff88004117f310
[…] ? nf_tables_newchain+0x21a4/0x2fa0 ffff88004117f358
[…] nf_tables_newchain+0x21a4/0x2fa0 ffff88004117f360
[…] ? nf_tables_addchain.constprop.0+0x1fc0/0x1fc0 ffff88004117f458
[…] ? nla_get_range_signed+0x4a0/0x4a0 ffff88004117f488
[…] ? lock_acquire+0x16f/0x320 ffff88004117f490
[…] ? find_held_lock+0x3b/0xe0 ffff88004117f4b0
[…] ? __nla_parse+0x45/0x80 ffff88004117f500
[…] nfnetlink_rcv_batch+0xbca/0x19a0 ffff88004117f550
[…] ? nfnetlink_net_exit_batch+0x120/0x120 ffff88004117f618
[…] ? __sanitizer_cov_trace_switch+0x63/0xe0 ffff88004117f720
[…] ? gr_acl_handle_mmap+0x1c4/0x320 ffff88004117f7c0
[…] ? nla_get_range_signed+0x4a0/0x4a0 ffff88004117f7e8
[…] ? gr_is_capable+0x6f/0xe0 ffff88004117f830
[…] ? __nla_parse+0x45/0x80 ffff88004117f860
[…] ? skb_pull+0x103/0x1a0 ffff88004117f880
[…] nfnetlink_rcv+0x3db/0x4a0 ffff88004117f8b0
[…] ? nfnetlink_rcv_batch+0x19a0/0x19a0 ffff88004117f8d8
[…] ? netlink_lookup+0xe2/0x240 ffff88004117f900
[…] netlink_unicast+0x74b/0xb00 ffff88004117f930
[…] ? netlink_attachskb+0xb20/0xb20 ffff88004117f980
[…] ? __check_object_size+0x3e/0xaa0 ffff88004117f998
[…] ? security_netlink_send+0x51/0x160 ffff88004117f9c8
[…] netlink_sendmsg+0xa03/0x1200 ffff88004117f9f8
[…] ? netlink_unicast+0xb00/0xb00 ffff88004117fa70
[…] ? netlink_unicast+0xb00/0xb00 ffff88004117fac8
[…] ? ____sys_sendmsg+0xe2a/0x1040 ffff88004117faf8
[…] ____sys_sendmsg+0xe2a/0x1040 ffff88004117fb00
[…] ? kernel_recvmsg+0x300/0x300 ffff88004117fb60
[…] ? reacquire_held_locks+0xe9/0x260 ffff88004117fbc8
[…] ___sys_sendmsg+0x138/0x200 ffff88004117fbf8
[…] ? do_recvmmsg+0x7e0/0x7e0 ffff88004117fc30
[…] ? lockdep_hardirqs_on_prepare+0x101/0x1e0 ffff88004117fc50
[…] ? lock_acquire+0x16f/0x320 ffff88004117fd20
[…] ? lock_acquire+0x16f/0x320 ffff88004117fd58
[…] ? find_held_lock+0x3b/0xe0 ffff88004117fd70
[…] __sys_sendmsg+0x17a/0x260 ffff88004117fdc8
[…] ? __sys_sendmsg_sock+0x80/0x80 ffff88004117fdf0
[…] ? syscall_trace_enter+0x15e/0x2c0 ffff88004117fe98
[…] do_syscall_64+0x7d/0x400 ffff88004117fec8
[…] entry_SYSCALL_64_safe_stack+0x4a/0x60 ffff88004117fef8
</TASK>
==================================================================
The out-of-bounds report, though, is a red herring as it is for an
access that shouldn't have happened in the first place.
When nf_nat_init() fails to register its BPF kfuncs, it'll unwind and,
among others, call unregister_pernet_subsys() to deregister its per-net
ops. This makes the previously allocated net id available for reuse by
the next caller of register_pernet_subsys(), in our case, synproxy.
However, 'nat_net_id' will still hold the previously allocated value.
If nf_nat.o gets build as a module, all this doesn't matter. A failed
initialization routine makes the module fail to load and any dependent
module won't be able to load either. However, if nf_nat.o is built-in,
a failing init won't /completely/ make its functionality unavailable to
dependent modules, namely the code and static data is still there, free
to be called by modules like nft_chain_nat.ko.
Case in point, nft_chain_nat registers hooks that'll call into nf_nat
which, in our case, failed to initialize and therefore won't have a
valid net id nor related net_nat object any more.
Code in nf_nat, namely nf_nat_register_fn() and nf_nat_unregister_fn(),
still making use of the reallocated net id, lead to a type confusion as
the call to net_generic() will no longer return memory belonging to an
object suited to fit 'struct nat_net' but 'struct synproxy_net' instead.
The latter is only 24 bytes on 64-bit systems, much smaller than struct
nat_net which is 176 bytes, perfectly explaining the OOB KASAN report.
Detect and handle a failed nf_nat_init() by testing the 'nf_nat_hook'
pointer which will be reset to NULL on initialization errors to prevent
the usage of an invalid nat_net pointer.
As this check is only needed when nf_nat.o is built-in, guard it by
'#ifndef MODULE...'.
Fixes: cbc1dd5b65 ("netfilter: nf_nat: Fix possible memory leak in nf_nat_init()")
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The conntrack lookup and allocation kfuncs take an opts pointer
together with an opts__sz argument. The verifier checks only the memory
range described by opts__sz, but the wrappers unconditionally write
opts->error whenever the internal lookup or allocation helper returns an
error.
For an invalid size smaller than the end of opts->error, that write can
land outside the verifier-checked range. Keep returning NULL for invalid
arguments, but only report the error through opts->error when the
supplied size includes the field.
This preserves error reporting for the supported 12-byte and 16-byte
layouts, and for other invalid sizes that still include opts->error.
Fixes: b4c2b9593a ("net/netfilter: Add unstable CT lookup helpers for XDP and TC-BPF")
Fixes: d7e79c97c0 ("net: netfilter: Add kfuncs to allocate and insert CT")
Signed-off-by: Yiyang Chen <chenyy23@mails.tsinghua.edu.cn>
Link: https://lore.kernel.org/r/9535e781fe14449b1d4e9bbc3baa7566a93bf512.1781765747.git.chenyy23@mails.tsinghua.edu.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch replaces the timer API by GC worker approach for
expectations, as it already happened in many other subsystems.
Use the existing conntrack GC worker to iterate over the local list of
expectations in the master conntrack to reap expired expectations.
Check IPS_HELPER_BIT to run GC for expectations, set it on for nft_ct
expectation which nevers sets it. Hold the expectation spinlock while
iterating over the master conntrack expectation list to synchronize with
nf_ct_remove_expectations(). This also performs runtime packet path
garbage collection through the expectation insertion and lookup
functions while walking over one of the chains of the global expectation
hashtables. Unconfirmed conntrack entries are skipped since ct->ext can
be reallocated and dying are skipped since those will be gone soon.
Set on IPS_HELPER_BIT if the helper ct extension is added, then the new
GC worker does not need to bump the ct refcount to check if the ct->ext
helper is available.
This removes the extra bump on the refcount for expectation timers, this
allows to remove several nf_ct_expect_put() calls after the unlink,
after this update only refcount remains at 1 while on the expectation
hashes.
This patch implicitly addresses a race with the existing timer API
allowing an expectation to access a stale exp->master pointer which has
been already released when expectation removal loses races with an
expiring timer, ie. timer_del() reporting false.
Add a new NF_CT_EXPECT_DEAD flag to reap this expectation via GC. This
is needed by nf_conntrack_unexpect_related() which is called in error
paths to invalidate newly created expectations that has been added into
the hashes. These expectactions cannot be inmediately released as GC or
nf_ct_remove_expectations() could race to make it. On expectation
insert, the runtime GC reaps stale expectations before checking the
expectation limit set by policy.
Set current timestamp in nf_ct_expect_alloc(), then add the expectation
policy timeout (or custom timeout specified added on top of this) to
specify the expectation lifetime.
Fixes: bffcaad9af ("netfilter: ctnetlink: ensure safe access to master conntrack")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
LLM points out that the skip causes unitialised stack array to
propagate down into dev_fill_forward_path(). Its not clear to me that
there is a guarantee that a later ctx.dev->netdev_ops->ndo_fill_forward_path()
would always fix this up.
Cc: Felix Fietkau <nbd@nbd.name>
Fixes: 45ca3e6199 ("netfilter: nft_flow_offload: skip dst neigh lookup for ppp devices")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Blamed commit added NFT_META_BRI_IIFHWADDR to the set validate callback,
yet this is a get operation.
Add a get validate callback and move the NFT_META_BRI_IIFHWADDR key
there.
AFAICS this is harmless, NFT_META_BRI_IIFHWADDR can deal with a NULL
input device and the set handler ignores a NFT_META_BRI_IIFHWADDR
operation, but it allows to read 4 bytes off bridge skb->cb[].
Fixes: cbd2257dc9 ("netfilter: nft_meta_bridge: introduce NFT_META_BRI_IIFHWADDR support")
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>
Large offsets were rejected based on netlink policy, but blamed commit
removed the policy without updating nft_payload_inner_init() to use the
truncation-check helper.
Silent truncation is not a problem, but not wanted either, so add a
check.
Fixes: 077dc4a275 ("netfilter: nft_payload: extend offset to 65535 bytes")
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>
Sashiko noticed that when destroying a set,
cancel_delayed_work_sync() was called while gc
calls queue_delayed_work() unconditionally which
can lead not to properly shutting down the gc.
Fixes: f66ee0410b ("netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Sashiko pointed out that kfree_rcu() was called before
rcu_assign_pointer() in handling the comment extension.
Fix the order so that rcu_assign_pointer() called first.
Fixes: b57b2d1fa5 ("netfilter: ipset: Prepare the ipset core to use RCU at set level")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The pair of the patch "netfilter: ipset: Don't use test_bit() in lockless
RCU readers in hash types" for the bitmap types.
Fixes: 02a3231b6d ("netfilter: nf_conntrack_expect: store netns and zone in expectation")
Fixes: b0da3905bb ("netfilter: ipset: Bitmap types using the unified code base")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Sashiko pointed out that there are a few lockless RCU readers
using test_bit() which is a relaxed atomic operation and
provides no memory barrier guarantees. Use test_bit_acquire()
instead where the operation may run parallel with add/del/gc,
i.e. is not one from the next cases
- protected by region lock
- in a set destroy phase
- in a new/temporary set creation phase
Fixes: 18f84d41d3 ("netfilter: ipset: Introduce RCU locking in hash:* types")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fix nf_flow_ip6_tunnel_proto() to use pskb_may_pull() instead of
skb_header_pointer() to ensure the outer IPv6 header is in the skb
headroom, which is required for subsequent packet processing. Move
ctx->offset update inside the IPPROTO_IPV6 conditional block since it
should only be adjusted when an IP6IP6 tunnel is actually detected.
Simplify the rx path by removing ipv6_skip_exthdr() and checking
ip6h->nexthdr directly, as the flowtable fast path only handles simple
IP6IP6 encapsulation without extension headers.
Drop the tunnel encapsulation limit destination option support from the
tx path to match, since the rx path no longer handles extension headers.
Remove the encap_limit parameter from nf_flow_offload_ipv6_forward(),
nf_flow_tunnel_ip6ip6_push() and nf_flow_tunnel_v6_push(), along with
the ipv6_tel_txoption struct and related headroom/MTU adjustments.
Fixes: d98103575d ("netfilter: flowtable: Add IP6IP6 rx sw acceleration")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
xt_cluster_mt() treats any non-NULL nf_ct_get() result as a fully
initialized conntrack and passes it to xt_cluster_hash().
This causes a state confusion bug when the raw table CT target attaches
a template conntrack to skb->_nfct before normal conntrack processing.
Templates carry IPS_TEMPLATE status but do not have a valid tuple for
hashing yet, so xt_cluster_hash() can hit its WARN_ON() path on the
zeroed l3num field.
Reject template conntracks before hashing them. This matches existing
netfilter handling for template objects and avoids hashing incomplete
conntrack state.
Fixes: 0269ea4937 ("netfilter: xtables: add cluster match")
Cc: stable@vger.kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Assisted-by: Codex:GPT-5.4
Signed-off-by: Wyatt Feng <bronzed_45_vested@icloud.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The br_netfilter fake rtable is embedded in struct net_bridge and is
attached to bridged packets with skb_dst_set_noref(). If such a packet is
queued to NFQUEUE, __nf_queue() upgrades that fake dst with
skb_dst_force().
At that point the queued skb can hold a real dst reference after bridge
teardown has started. The problem is not that every bridged packet needs
its own dst reference. The problem is that NFQUEUE can keep the bridge
private fake dst alive after unregister begins.
Fix this by keeping the bridge fake dst model unchanged and pinning the
bridge master device only while the packet sits in NFQUEUE. Record the
bridge device in nf_queue_entry when the queued skb carries a bridge fake
dst, take a device reference for the queue lifetime, and drop it when the
queue entry is freed.
Also make sure queued entries are reaped when that bridge device goes
down, and drop the redundant nf_bridge_info_exists() test from the fake
dst detection.
This keeps netdev_priv(br->dev) alive until verdict completion, so the
embedded fake rtable and its metrics backing storage cannot be freed out
from under dst_release(). It also avoids the constant refcount bump and
avoids using ipv4-specific dst helpers for IPv6 bridge traffic.
Fixes: 34666d467c ("netfilter: bridge: move br_netfilter out of the core")
Cc: stable@kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Haoze Xie <royenheart@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
OpenWrt has recently migrated many platforms to kernel 6.18. On the
MediaTek platform, which supports hardware network offloading, WiFi
connections accelerated via the WED path were observed to drop after
roughly 300 seconds.
After several debugging sessions, assisted by the Claude LLM, the
problem was narrowed down as follows:
nf_flow_table_extend_ct_timeout() extends ct->timeout for offloaded
flows using:
cmpxchg(&ct->timeout, expires, new_timeout);
'expires' comes from nf_ct_expires(ct) and is a relative value, while
ct->timeout holds an absolute timestamp. The two are never equal, so
the cmpxchg always fails and the timeout is never extended.
This goes unnoticed for most flows, but a long-lived hardware (WED)
offloaded flow on MediaTek MT7986 eventually has ct->timeout decay to
zero, the conntrack entry is reaped and the connection breaks.
Open-code the relative value from a single READ_ONCE(ct->timeout)
snapshot and compare against that same absolute snapshot in the
cmpxchg, so the timeout extension actually takes effect while the
datapath remains authoritative if it updates ct->timeout concurrently.
Fixes: 03428ca5ce ("netfilter: conntrack: rework offload nf_conn timeout extension logic")
Cc: stable@vger.kernel.org
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Adrian Bente <adibente@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
