Incoming skbs passing through netfilter flowtable offload hooks (or XFRM
offload path) might already carry a ref-counted dst_entry assigned during
earlier RX or routing steps.
Calling skb_dst_set_noref() when skb already holds a ref-counted dst
overwrites skb->_skb_refdst, leaking the previous dst_entry reference
count and triggering a DEBUG_NET_WARN_ON_ONCE assertion in
skb_dst_check_unset():
WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170
WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234
WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864
Drop any existing dst_entry reference with skb_dst_drop(skb) before
setting the non-referenced flowtable destination.
Fixes: 2a79fd3908 ("netfilter: nf_flow_table: attach dst to skbs")
Reported-by: syzbot+76d4e3a055aec3b007ec@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a71b141.9511d2ce.1fc5b9.033b.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://patch.msgid.link/20260804093328.1831847-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Sashiko warns that local attacker can modify the packet
while it is processed by IPVS. Some places read the
IP ihl field multiple times which can cause out-of-bounds
access. One such place is ip_vs_nat_icmp where we
can write after the validated area.
Fix it by providing ciph argument just like it is done for
IPv6 and use ciph->len as offset to the embedded transport
header.
Modify some IPv4 header checks by reading the ihl field
only once.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260722101517.36313-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In the initial ipset rhashtable conversion RFC series syzbot reported
following splat:
BUG: sleeping function [..] at kernel/irq_work.c:289
in_atomic(): 1, [..]
irq_work_sync.. kernel/irq_work.c:289
rhashtable_free_and_destroy.. lib/rhashtable.c:1295
hash_netport4_destroy.. net/netfilter/ipset/ip_set_hash_gen.h:420
ip_set_destroy_set_rcu.. net/netfilter/ipset/ip_set_core.c:1169
rcu_core.. kernel/rcu/tree.c:2897
This is because post-rhashtable-conversion hash implementation needs
to schedule in the destroy callback. At this time this isn't allowed.
Replace existing call_rcu() based destruction with rcu_work api.
Also allows to undo split of set destruction and gc work cancelling in
a future patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Preparation patch. Once the ipset hash table is replaced with rhashtable
these functions are needed. Add them in extra commit to have reviewable
chunks.
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 hash types do not acquire set->lock, they use 'region locking' where
only part of the hash table is locked. Parallel inserts and deletes are
possible and CPUs can race on ->ext_size update. Switch to atomic64_t.
This leaves another bug unresolved: there still can be a race on
comment extension re-init. This will be handled in a later commit
when converting to rhashtable backend.
Fixes: f66ee0410b ("netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
According to sashiko, the current bookkeeping of cidr values are unsafe
on weakly-ordered architectures. Replace the in-place updating with an
RCU based method: create the new bookeeping structure, update and replace
the old one with the new. Downside that we need to allocate memory when
deleting a cidr entry - in case of memory pressure fall back to leave holes
which possibility is taken into account at evaluation time.
Thanks to Pablo (Pablo Neira Ayuso <pablo@netfilter.org>) and Cyntia
(Cynthia <cynthia@kosmx.dev>) for helping me in debugging which resulted
the patch "netfilter: ipset: allocate the proper memory for the generic
hash structure" on which this very patch depends.
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
IPVS estimator kthread 0 starts with zeroed chain and tick limits until
its initial calculation phase completes. If network namespace teardown
clears ipvs->enable during that phase, ip_vs_est_calc_phase() can return
without installing positive limits.
The kthread can then continue into its main loop and drain
est_temp_list with zero chain_max, tick_max and est_max_count values.
Each enqueue consumes one available tick row, but est_count never
reaches the zero est_max_count value. After all rows are consumed, the
row lookup returns IPVS_EST_NTICKS and ip_vs_enqueue_estimator() writes
past the ticks and tick_len arrays.
Exit kthread 0 after the calculation phase if the kthread is stopping or
IPVS has been disabled. That keeps temporary estimators from being
drained after the limits failed to initialize.
Estimator kthreads can now self-exit before teardown or reload stops
kd->task. Keep an extra task reference after creation and release it
with kthread_stop_put(), so kd->task remains valid until the stop paths
consume that reference.
Fixes: 705dd34440 ("ipvs: use kthreads for stats estimation")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Commit be0502a3f2 ("netfilter: conntrack: tcp: only close if RST
matches exact sequence") keeps an established conntrack entry in
ESTABLISHED when an in-window RST does not match the expected sequence
number exactly, so the endpoint can validate the RST with a challenge
ACK.
The timeout selection nevertheless uses the CLOSE timeout for every RST
packet. The bug is that timeout selection is based on the packet type,
not on the state transition result: even when RST validation keeps
new_state in ESTABLISHED, the timeout is still forced to
TCP_CONNTRACK_CLOSE.
Linux TCP independently rate limits challenge ACKs per socket. A second
non-exact RST can therefore arrive after the first challenge ACK has
restored the timeout but before the rate limit expires. The second RST
lowers the timeout to 10 seconds again while the endpoint suppresses the
second challenge ACK, allowing the conntrack entry to expire while both
TCP endpoints remain established.
Using the ESTABLISHED timeout for such RSTs would avoid this short
expiration window, but it could also retain stale entries for the
five-day default because conntrack cannot reliably match the endpoint's
exact TCP state.
Use the UNACK timeout for RST packets that leave the conntrack entry in
TCP_CONNTRACK_ESTABLISHED. Exact-match RSTs and accepted RST packet
trains still fall through to timeouts[new_state], which preserves the
CLOSE timeout when conntrack accepts the RST as closing the flow.
This avoids the aggressive 10-second expiration window for non-exact
RSTs while preserving the short timeout for RSTs that conntrack accepts
as closing the flow.
Suggested-by: Florian Westphal <fw@strlen.de>
Reported-by: Minghao Zhang <zhangmh25@mails.tsinghua.edu.cn>
Reported-by: Jianjun Chen <jianjun@tsinghua.edu.cn>
Signed-off-by: Minghao Zhang <zhangmh25@mails.tsinghua.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When fetching the dst_entry from the skb, check if it valid, ie. this is
not a template dst, for extensions that can be used from the netdev
ingress and egress chains.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_flow_tunnel_update_route() can lazy fail, leaving an incomplete
forward path set ip. The route lookup also happens twice, once from
dev_fill_forward_path() and again in this aforementioned function.
Update ipip and ip6ip6 not to release the dst_entry and pass it on
via the tunnel forward path information.
In case of failure when setting up the forwarding path, release the
tunnel dst that was provided via dev_fill_forward_path().
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The flowtable path discovery stops at the DSA user device when setting
up the forward path. Let's just report there is no more devices after
the DSA user port through the .fill_forward_path interface.
No functional changes are intended.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check that device belongs to the flowtable right after the flowtable
discovery path. This is a preparation patch to obtain the dst entry
from the .fill_forward_path in tunnels.
No functional changes are intended.
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
info->indev and info->outdev refer to the same device, a single
info->dev field is sufficient.
While at it, remove unused router parameter from the flowtable path
discovery function.
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When get_ct_or_tuple_from_skb() falls back to looking for a connection
via nf_conntrack_find_get(), a successful lookup sets ct but leaves
tuple and zone unupdated.
If the packet belongs to a reply flow, tuple will remain in the reply
direction. As conncount relies on the original direction tuple to count
the connections consistenly, passing an unnormalized reply tuple could
lead to problems.
Fix this by making sure that tuple and zone are normalized.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
As per Documentation/process/deprecated.rst, open-coded kmalloc
assignments for struct objects are deprecated. Replace
kzalloc(sizeof(*ptr), GFP_KERNEL) with kzalloc_obj() and
kvmalloc_array(n, sizeof(*ptr), GFP_KERNEL) with kvmalloc_objs()
in ip_vs_rht_alloc().
Compile tested with CONFIG_IP_VS=y and runtime tested using
tools/testing/selftests/net/netfilter/ipvs.sh on x86_64/QEMU.
Signed-off-by: Subasri S <subasris1210@gmail.com>
Reviewed-by: Phil Sutter <phil@nwl.cc>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Store the event cache in the expectation instead of accessing the
exp->master cache, as a step forward towards turning the exp->master
into a cookie.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pass master conntrack as argument to helper functions that parse the
packet payload, instead of using exp->master. Although accessing
exp->master is safe in this case because it refers to the master
conntrack in used by this skb, remove it to step towards turning the
exp->master field into a cookie value.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In case of route updates, tear down flow entries with stale dst to give
them a chance to obtain a fresh route.
This is specifically useful for hardware offloaded entries, where the
flowtable software dataplane sees no packet, where the existing check
for stale dst entries does not help.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
sashiko says:
If map_addr() changes the packet length, such as when the public NAT IP
string is shorter or longer than the internal IP, coff will still point to
the offset relative to the pre-mangled packet.
If the packet shrinks, coff could overshoot the correct position,
potentially causing the next ct_sip_parse_header_uri() call to silently
skip bytes and miss subsequent Contact headers. Could this lead to a
failure to NAT those subsequent headers and leak internal network details?
Fixes: c978cd3a93 ("[NETFILTER]: nf_nat_sip: translate all Contact headers")
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
sashiko reports:
Is it intentional that the new parameter validation callback is applied
only to the NFPROTO_IPV4 match?
Fixes: 68fc6c6470 ("netfilter: xt_tcpmss: add checkentry for parameter validation")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Under synflood conditions binding these handlers to system_long_wq may
pin them to a saturated CPU.
We've observed improved throughtput on a DPDK/VPP application with this
change, which we attribute to the reduced context switching.
Neither handler has per-CPU data dependencies nor cache locality
requirements that would prevent this change.
Signed-off-by: Ismael Luceno <iluceno@suse.de>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_payload_offload_mask() builds the offload match mask for a payload
expression that covers only part of a header field. For a partial IPv6
address match (field_len = 16, priv_len = 1) that shift is 1 << 120, which
is undefined on the 32-bit int operand. It also trims only one word, so
the remaining words stay 0xffffffff (and when priv_len is a multiple of 4
the trim is skipped entirely), leaving the mask covering more bytes than
the rule matches.
UBSAN: shift-out-of-bounds in net/netfilter/nft_payload.c:278:20
shift exponent 120 is too large for 32-bit type 'int'
...
The match is byte-granular and struct nft_data is zero-initialised, so the
correct mask is simply the first priv_len bytes set to 0xff. Set those
bytes directly and drop the word/shift trimming; this removes the undefined
shift and no longer over-masks the trailing bytes.
Fixes: a5d45bc0dc ("netfilter: nftables_offload: build mask based from the matching bytes")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Sashiko warns that ip_vs_nat_icmp() unconditionally mangles the
payload for embedded non-first IPv4 fragments. The problem is
in the very old inverted pp->dont_defrag check which should not
continue when embedded is a non-first TCP/UDP/SCTP fragment.
Check for embedded non-first fragment is also missing from
ip_vs_out_icmp_v6(), it is needed before any connection
lookups that expect ports after the network headers.
Drop the blocking code from ip_vs_in_icmp_v6() which prevents
ICMPv6 from local clients to use non-MASQ forwarding.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260720201122.79882-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The offsets we use to packet headers and payloads should be
based on skb->data. We even already respect non-zero
network offset in ip_vs_fill_iph_skb() but some places
do it wrongly and support only zero offset which is expected
for the IP layer where IPVS has hooks.
Change all places that instead of skb->data use offsets based
on the network header (skb_network_header, ip_hdr, etc) because
this doubles the network offset as noted by Sashiko.
For ip_vs_nat_icmp_v6() we can even rely on the IPv6 header
parsing done by the caller.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260710143733.29741-2-fw%40strlen.de
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip_vs_in_icmp_v6() is missing checksum validation for ICMPv6
packets from clients. In fact, as for TCP/UDP we should
validate the checksum for ICMP packets only when we
mangle the packets on MASQ or on reply for tunnel.
Also, Sashiko points out that handle_response_icmp() being
common for IPv4 and IPv6 is missing the pseudo-header
calculation while validating ICMPv6 messages from real
servers which is a problem if checksum is not validated
by the hardware.
Fix the problems by creating ip_vs_checksum_common_check()
helper and use it for TCP/UDP/ICMP both for IPv4 and IPv6.
Rely on the nf_checksum() for validating the ICMP messages
but use it also for TCP and UDP.
Use correct IP offset for IP_VS_DBG_RL_PKT for TCP/UDP/SCTP.
IPVS packets (TCP/UDP/SCTP/ICMP) do not need checksum
validation on LOCAL_OUT (local clients or local real
servers) and on FORWARD (traffic from servers on LAN).
Do it only on LOCAL_IN, in case nf_checksum() is not
called on PRE_ROUTING.
Also, ip_vs_checksum_complete() can be marked static.
Fixes: 2a3b791e6e ("IPVS: Add/adjust Netfilter hook functions and helpers for v6")
Link: https://sashiko.dev/#/patchset/20260708180315.77413-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The XT_HASHLIMIT_RATE_MATCH flag mode changes the semantics of the
dsthash_ent structure which represents an entry in the hashtable. There
is a union area which uses a different layout to express the rate match
mode.
Update .checkentry path to validate the XT_HASHLIMIT_RATE_MATCH mode
flag is requested by two or more different rules that refer to the same
hashtable. Otherwise, uninitialized access to the burst field in the
union is possible.
Reject the use of the XT_HASHLIMIT_RATE_MATCH mode flag if set on by
revision less than 3 too.
Fixes: bea74641e3 ("netfilter: xt_hashlimit: add rate match mode")
Reported-and-tested-by: Talha Berk Arslan <talha.anything.info@gmail.com>
Link: https://patch.msgid.link/20260721074629.668-1-talha.anything.info@gmail.com/
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The nft_object rhltable is global, this allows for accessing objects
that are being dismangled from lookup path by other existing netns.
Given the nft_obj_destroy() releases the object inmediately, this might
lead to use-after-free of these objects that are being released.
Make the existing rhltable per table to address this issue to deal with
with the nft_rcv_nl_event() path too.
Update nft_obj_lookup() to take the table as non-const, otherwise,
compiler complains when passing the objname_ht to rhltable_lookup().
Fixes: 4d44175aa5 ("netfilter: nf_tables: handle nft_object lookups via rhltable")
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Synced conns can be created with one forwarding method
and later updated with different one after the dest
server is configured. This needs adjusting the hashing
for node hn1 because only MASQ supports double hashing.
Modify conn_tab_lock() to support seeking for hash node
hn0 together with adding for hn1. By this way we can
safely modify the forwarding method and hn1.hash_key
under bucket lock for the first node hn0. The forwarding
method is also protected by cp->lock as it is part of
cp->flags.
Fix the usage of stale idx/idx2 values in conn_tab_lock
after jumping to the retry label. Instead, use idx/idx2
values just to order the locking for the old/new tables.
Reported-by: Zhiling Zou <roxy520tt@gmail.com>
Link: https://patch.msgid.link/1b914f41d725bc064c9ba9830dc8169329737270.1782540466.git.roxy520tt@gmail.com/
Link: https://sashiko.dev/#/patchset/CALMqdkR704S2BG_QD_bgHTFp2%2B1QCi7n0T4zoZyTo8mDZevYSA%40mail.gmail.com
Fixes: f20c73b046 ("ipvs: use more keys for connection hashing")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Synced connections can be created before their destination exists. When
the destination is later added, ip_vs_bind_dest() copies connection flags
from the destination into cp->flags.
IP_VS_CONN_F_ONE_PACKET connections are not synced. If a synced
connection inherits IP_VS_CONN_F_ONE_PACKET while it is already hashed,
expiry can treat it as a one-packet connection and skip unlinking the
existing conn_tab node, leaving stale hash nodes pointing at a freed
struct ip_vs_conn.
Drop IP_VS_CONN_F_ONE_PACKET from destination flags when binding synced
connections.
Fixes: 26ec037f98 ("IPVS: one-packet scheduling")
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: Xin Liu <bird@lzu.edu.cn>
Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Zhiling Zou <roxy520tt@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
mtype_resize() copies comment pointers with memcpy(), not the comment
objects themselves. During the window after an entry has been copied but
before the table swap and backlog replay, the old table is still
published for packet-side updates while the replacement-table entry
already holds the same ip_set_comment_rcu pointer.
If xt_SET --add-set ... --exist hits that old entry in this window,
mtype_add() calls ip_set_init_comment() even though packet-side adds
carry no comment payload. That call frees the shared comment through the
old entry, so the replacement-table entry now holds a stale pointer.
When the queued add is replayed on the new table, mtype_add() calls
ip_set_init_comment() again and strlen() dereferences the stale pointer.
Fix this in mtype_add() by skipping ip_set_init_comment() when
ext->target marks a packet-side add. Userspace adds still update
comments, while packet-side adds can no longer free comment storage
shared with a resize copy.
Fixes: f66ee0410b ("netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports")
Cc: stable@vger.kernel.org
Signed-off-by: David Lee <david.lee@trailofbits.com>
Assisted-by: Codex:gpt-5.5
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new function to insert a pair of expectations, this is required by
the SIP and H323 NAT helpers. The spinlock is held to check if there is
a slot for both expectations, in such case, insert them.
This removes the need for nf_ct_unexpect_related() inside the loop to
find a pair of consecutive ports, otherwise inserting expectations whose
dead flag is already set on can happen.
Bump master_help->expecting for the expectation class after checking if
the expectation fits in the master expectation list, which is needed for
this new _pair() function variant to run the eviction routine including
the preallocated slot for the first expectation in the pair.
Fixes: b8b09dc2bf ("netfilter: nf_conntrack_expect: use conntrack GC to reap expectations")
Reported-by: Jaeyeong Lee <iostreampy@proton.me>
Link: https://patch.msgid.link/178377968720.33756.12204817361601593230@proton.me/
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
sip_help_tcp() stores the size change of each NAT-rewritten SIP message
in s16 diff and accumulates it in s16 tdiff, but a single message can
grow by more than S16_MAX while the packet stays under the 65535
enlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long
Contact list expands the message by tens of kilobytes. diff then wraps,
and "datalen = datalen + diff - msglen" yields a huge unsigned datalen,
so the next iteration's ct_sip_get_header() reads past the linearized skb
tail.
Widen diff, tdiff and the seq_adjust hook to s32. Both are bounded by the
65535 byte packet limit, and the seqadj core is already s32
(nf_ct_seqadj_set() takes s32), so no previously accepted input is
rejected.
BUG: KASAN: use-after-free in ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)
Read of size 1 at addr ffff888010800000 by task ksoftirqd/1/25
ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)
sip_help_tcp (net/netfilter/nf_conntrack_sip.c:1694)
nf_confirm (net/netfilter/nf_conntrack_proto.c:183)
nf_hook_slow (net/netfilter/core.c:619)
ip6_output (net/ipv6/ip6_output.c:246)
ip6_forward (net/ipv6/ip6_output.c:690)
ipv6_rcv (net/ipv6/ip6_input.c:351)
__netif_receive_skb_one_core (net/core/dev.c:6212)
process_backlog (net/core/dev.c:6676)
__napi_poll (net/core/dev.c:7735)
net_rx_action (net/core/dev.c:7955)
handle_softirqs (kernel/softirq.c:622)
run_ksoftirqd (kernel/softirq.c:1076)
...
Fixes: f5b321bd37 ("netfilter: nf_conntrack_sip: add TCP support")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Link: https://patch.msgid.link/netfilter-devel/20260712234201.3213635-1-xmei5@asu.edu
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Alice Mikityanska says:
====================
BIG TCP for UDP tunnels
This series is a follow-up to "BIG TCP without HBH in IPv6", and it adds
support for BIG TCP IPv4/IPv6 workloads in vxlan and geneve. Now that
IPv6 BIG TCP doesn't require stripping the HBH in all various
combinations in tunneled traffic, adding BIG TCP becomes feasible.
Patch 01 adds accessors for the length field in the UDP header, as
suggested by Paolo in review. The usage of udp_set_len is then added in
the following patches that start using length=0 in BIG TCP UDP packets.
Patches 02-04 close the gaps that prevent BIG TCP packets from going
through UDP tunnel code.
Patch 05 validates packets in udp_gro_receive to exclude packets with
length=0 from GRO aggregation.
Patch 06 is for proper formatting in tcpdump (set UDP len to 0 rather
than a trimmed value on overflow).
Patches 07-08 bump up tso_max_size for VXLAN and GENEVE.
Patch 09 adds selftests.
====================$
Link: https://patch.msgid.link/20260710134242.216538-1-alice.kernel@fastmail.im
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Wherever a GSO packet can occur, and its length is used to fill the UDP
header, use udp_set_len that assigns 0 if the length doesn't fit 16
bits, so that the packet can be properly parsed and segmented later,
instead of having truncated length.
Use udp_get_len in udp_validate_len to treat BIG TCP packets as valid.
Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260710134242.216538-4-alice.kernel@fastmail.im
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Since BIG TCP for UDP tunnels will start using len=0 in the UDP header
as an indicator of a GSO packet bigger than 65535 bytes, this commit
introduces the following getter and setters to use tree-wide, in order
to explicitly mark places where len=0 may be expected, and handle them
properly:
1. udp_set_len() sets uh->len to its real value if it's not bigger than
65535, and to 0 otherwise: to be used in GSO context with aggregated
packets.
2. udp_set_len_short() is to be used when the length is known to fit 16
bits. It WARNs when the caller tries to assign a bigger value if
CONFIG_DEBUG_NET=y.
3. udp_get_len_short() returns len in host byte order: to be used on the
RX side to deal with non-aggregated packets, or to access the raw value
of the len field.
4. udp_get_len() decodes uh->len set by udp_set_len(). It checks whether
the packet is GSO to guard from malformed packets.
At the moment udp_set_len() is not used, a following commit will start
using it after enabling len>65535 for GSO.
Raw uh->len (in network byte order) is still accessed in a few places
for checksum calculation purposes, and to decode len=0 in udpv6_rcv for
jumbograms. udp_rcv and udpv6_rcv will be addressed by the commit that
starts using udp_set_len() to set UDP len=0 for BIG TCP packets in UDP
tunnels.
Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://patch.msgid.link/20260710134242.216538-2-alice.kernel@fastmail.im
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
... and must not be subjected to the 'nul terminated' constraint.
If the interface name is 15 characters long, the mask is 16-bytes
'0xff' (to cover for \0) and the valid device name is rejected.
Fixes: 8df772afc9 ("netfilter: x_physdev: reject empty or not-nul terminated device names")
Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/neutron/+bug/2159935
Signed-off-by: Florian Westphal <fw@strlen.de>
Sashiko reports for more incorrect IPv6 transport offsets.
The app code for TCP was assuming IPv4 network header
even after the ipvsh argument was provided. This can
cause problems with apps over IPv6. As for the only
official app in the kernel tree (FTP) this problem is
harmless because we use Netfilter to mangle the FTP
ports and we do not adjust the TCP seq numbers.
Also, provide correct offset of the ICMPV6 header in
ip_vs_out_icmp_v6() for correct checksum checks when
the IPv6 packet has extension headers.
Fixes: d12e12299a ("ipvs: add ipv6 support to ftp")
Fixes: 2a3b791e6e ("IPVS: Add/adjust Netfilter hook functions and helpers for v6")
Cc: stable@vger.kernel.org
Link: https://sashiko.dev/#/patchset/20260706101624.69471-1-zhaoyz24%40mails.tsinghua.edu.cn
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
The layer 2 encapsulation and layer 3 tunnel information in the xmit
path is taken from the other tuple, because the tunnel information that
is included in the tuple for hashtable lookups is also used to perform
the egress encapsulation in the transmit path.
This patch uses the correct direction when setting up the tunnel, the
original proposed patch to address this fix uses the reversed direction.
While at it, remove the redundant check to call dst_release() to drop
the reference on the dst that was obtained from the forward path, which
is not useful in the direct xmit path unless tunneling is performed.
Fixes: fa7395c02d ("netfilter: flowtable: support IPIP tunnel with direct xmit")
Cc: stable@vger.kernel.org
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
The "already exists" dedup logic in __nf_conncount_add() decides
whether a connection has already been counted and can be skipped instead
of incrementing the connlimit count. It compares the conntrack zone of a
list entry with the zone of the connection being added using
nf_ct_zone_id() and nf_ct_zone_equal(), passing conn->zone.dir or
zone->dir as the direction argument.
Those helpers take enum ip_conntrack_dir values: IP_CT_DIR_ORIGINAL is 0
and IP_CT_DIR_REPLY is 1. However, zone->dir is a u8 bitmask:
NF_CT_ZONE_DIR_ORIG is 1, NF_CT_ZONE_DIR_REPL is 2 and
NF_CT_DEFAULT_ZONE_DIR is 3. Passing that bitmask as the enum direction
shifts the meaning of every non-zero value. An ORIG-only zone passes 1
and is tested as REPLY, while REPL-only and default zones pass 2 or 3 and
test bits beyond the valid direction range. In those cases
nf_ct_zone_id() can fall back to NF_CT_DEFAULT_ZONE_ID instead of using
the real zone id, so different zones can be treated as equal and dedup
collapses to tuple equality alone.
nf_conncount stores and compares the original-direction tuple for a
connection. If an skb already has an attached conntrack entry,
get_ct_or_tuple_from_skb() explicitly copies
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, regardless of the packet's
ctinfo. Therefore the zone comparison in the tuple dedup path must use
IP_CT_DIR_ORIGINAL as well; the zone direction bitmask describes where a
zone id applies, not which direction this conncount tuple represents.
Fix the two dedup comparisons by passing IP_CT_DIR_ORIGINAL directly.
Do not special-case NF_CT_DEFAULT_ZONE_DIR and do not compare raw zone
ids: using the existing helpers with IP_CT_DIR_ORIGINAL preserves the
direction-aware NF_CT_DEFAULT_ZONE_ID fallback. A default bidirectional
zone contains the ORIG bit, so it naturally returns the real zone id;
reply-only zones continue to fall back for original-direction tuple
comparisons.
Fixes: 21ba8847f8 ("netfilter: nf_conncount: Fix garbage collection with zones")
Fixes: b36e4523d4 ("netfilter: nf_conncount: fix garbage collection confirm race")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Assisted-by: Claude-Code:GLM-5.2
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Signed-off-by: Florian Westphal <fw@strlen.de>
ecache_work_evict_list() redelivers DESTROY events for conntracks that
were moved to the per-netns dying_list after event delivery failed. It
sets a 10ms deadline:
stop = jiffies + ECACHE_MAX_JIFFIES
but then tests:
time_after(stop, jiffies)
This condition is true while the deadline is still in the future, so the
worker returns STATE_RESTART after the first successful redelivery in the
usual case. ecache_work() maps STATE_RESTART to delay 0, which turns the
redelivery path into one dying conntrack per workqueue dispatch and makes
the sent > 16 batching/cond_resched() path effectively unreachable.
A conntrack netlink listener whose receive queue is congested can make
DESTROY event delivery fail with -ENOBUFS. With sustained conntrack
churn, entries then accumulate on the dying_list and are only drained at
the degraded one-entry-per-dispatch rate once delivery succeeds again,
wasting CPU on back-to-back workqueue reschedules and prolonging
conntrack memory/resource pressure.
In a KASAN QEMU test with CONFIG_NF_CONNTRACK_EVENTS=y and
nf_conntrack.enable_hooks=1, a congested DESTROY listener caused 8192
nf_ct_delete() calls to return false and move entries to the dying_list.
After closing the listener, the unfixed kernel needed 7670 ecache_work()
entries to destroy 7669 conntracks. With this change, the same 8192
entries were destroyed by 2 ecache_work() entries.
Swap the comparison so the worker restarts only after the deadline has
expired.
Fixes: 2ed3bf188b ("netfilter: ecache: use dedicated list for event redelivery")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Assisted-by: Claude-Code:GLM-5.2
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Signed-off-by: Florian Westphal <fw@strlen.de>
xt_nat SNAT and DNAT target handlers assume IP-family conntrack state
is present and can dereference a NULL pointer when instantiated from an
unsupported family through nft_compat. A bridge-family compat rule can
therefore trigger a NULL-dereference in nf_nat_setup_info().
Reject non-IP families in xt_nat_checkentry() so unsupported targets
cannot be installed. Keep NFPROTO_INET allowed for valid inet NAT
compat users and leave the runtime fast path unchanged.
[ The crash was fixed via
9dbba7e694 ("netfilter: nft_compat: ebtables emulation must reject non-bridge targets"),
so this patch is no longer critical.
Nevertheless, NAT is only relevant for ipv4/ipv6, so this extra
family check is a good idea in any case. ]
Fixes: c7232c9979 ("netfilter: add protocol independent NAT core")
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: Florian Westphal <fw@strlen.de>
