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1,010 commits

Author SHA1 Message Date
Julian Anastasov
d93660df4d ipvs: revalidate ihl to prevent out-of-bounds access
While the outer IP header is already pulled into the skb head,
we must be careful and revalidate the embedded headers after
reading them from the skb frags to prevent out-of-bounds
access.

One such place reported by Sashiko is ip_vs_nat_icmp() where
local process can change the ihl field and after
skb_ensure_writable() we can see larger value which is a
problem for the ip_send_check(cih) calls.

Add check to drop the packet if the ihl field is changed.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260730183506.87473-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-08-10 20:27:15 +02:00
Kyle Zeng
e0ba936287 ipvs: clear IPv4 options after rebasing tunnel ICMP errors
ip_vs_in_icmp() rebases an skb from the outer ICMP packet to the
quoted original request before passing it to icmp_send(). However,
IPCB(skb)->opt still describes the outer IPv4 header.

A timestamp option in the outer header can therefore leave an offset
that points into the quoted transport header after the rebase.
__ip_options_echo() treats a byte at that stale location as the option
length and copies it into the fixed-size option storage on the
__icmp_send() stack, causing a stack out-of-bounds write.

Clear the stale option metadata after resetting the network header.
Keep the remaining control block fields, including the ingress
interface used by the ICMP response path.

Fixes: f2edb9f770 ("ipvs: implement passive PMTUD for IPIP packets")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6-sol Codex:gpt-5.5-cyber
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Co-developed-by: David Lee <david.lee@trailofbits.com>
Signed-off-by: David Lee <david.lee@trailofbits.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-08-10 20:27:07 +02:00
Yizhou Zhao
cdcc4e4618 ipvs: separate destination availability state
IPVS configuration paths update destination availability while connection
accounting updates destination overload state. The two independent states
share dest->flags, so their read-modify-write updates can race and lose one
another.

Keep OVERLOAD in flags, where the preceding patch serializes its updates
with dst_lock, and move AVAILABLE to cflags. This keeps configuration-
controlled availability out of the scheduler hot cacheline until a
scheduler needs to check it. It also prevents availability updates from
clobbering overload state.

The destination status bits are not exposed through the IPVS sockopt or
netlink interfaces, so keep their definitions in the internal IPVS header.

Readers can still observe stale destination state; this does not provide a
cross-field snapshot.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
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>
Link: https://lore.kernel.org/all/8913381c-1e02-35c7-0ec4-61de5a12fd35@ssi.bg/
Assisted-by: Claude-Code:GLM-5.2
Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-08-10 20:23:35 +02:00
Julian Anastasov
8f843441c4 ipvs: properly update the overload flag on dest edit
The upper/lower connection thresholds for dest can be changed,
so use ip_vs_dest_update_overload() to properly update the
dest overload flag.

The thresholds were not limited, fit them in the 0 .. INT_MAX
range as already done in ipvsadm.

As the thresholds are also read when connections are created
and expired, use WRITE_ONCE/READ_ONCE to access them.

As the lower threshold is optional, use (u - (u >> 2)) to
calculate the 75% default value based on the upper threshold
by preserving the integer rounding, as suggested by Yizhou Zhao.

Trigger flag update when totalconns reaches one of the
thresholds and use dst_lock to serialize the updating.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-08-10 20:14:54 +02:00
Julian Anastasov
04d2feaed8 ipvs: add totalconns for dest
Replace the inactconns dest counter with totalconns, now
inactconns can be obtained from totalconns - activeconns.
This reduces the atomic inc/dec ops for TCP/SCTP from
6 to 4 if the connection is established and then closed.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-08-10 20:14:20 +02:00
Julian Anastasov
99609cb0aa ipvs: return the csum validation for forward hook
Sashiko notes that playing games with the skb dst and rt
flags instead of providing hooknum is not a good idea
when validating the checksums.

Also, skipping checksum validation for FORWARD packets
risk silent data corruption, even if the only user is
the FTP-CMD packets coming from the real server.

Sashiko also noticed that by using common checksum
helper in the previous commit we actually fixed old bug
where the TCP/UDP checksum for IPv6 on CHECKSUM_COMPLETE
was not validated correctly.

Fixes: e876b75b90 ("ipvs: fix the checksum validations")
Link: https://sashiko.dev/#/patchset/20260722211420.153933-1-pablo%40netfilter.org
Link: https://sashiko.dev/#/patchset/20260727185024.67534-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260728202520.59179-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-07-31 15:58:30 +02:00
Julian Anastasov
646922a037 ipvs: avoid out-of-bounds write in ip_vs_nat_icmp
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>
2026-07-31 15:58:16 +02:00
Zhiling Zou
558f67f134 ipvs: stop estimator after disabled calc phase
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>
2026-07-31 15:56:23 +02:00
Julian Anastasov
da7d894c41 ipvs: clear the nfct flag under lock
Sashiko warns that cp->flags should be changed under cp->lock

Fixes: 35dfb01314 ("ipvs: queue delayed work to expire no destination connections if expire_nodest_conn=1")
Fixes: f0a5e4d7a5 ("ipvs: allow connection reuse for unconfirmed conntrack")
Link: https://sashiko.dev/#/patchset/CALMqdkR704S2BG_QD_bgHTFp2%2B1QCi7n0T4zoZyTo8mDZevYSA%40mail.gmail.com
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-07-23 18:17:19 +02:00
Julian Anastasov
342e24a339 ipvs: do not mangle ICMP replies for non-first fragments
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>
2026-07-23 18:08:22 +02:00
Julian Anastasov
15cab31a37 ipvs: fix places with wrong packet offsets
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>
2026-07-23 18:05:08 +02:00
Julian Anastasov
e876b75b90 ipvs: fix the checksum validations
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>
2026-07-23 18:04:40 +02:00
Julian Anastasov
712d2993be ipvs: adjust double hashing when fwd method changes
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>
2026-07-23 17:59:20 +02:00
Zhiling Zou
a63d2dbaeb ipvs: do not propagate one-packet flag to synced conns
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>
2026-07-23 17:59:02 +02:00
Julian Anastasov
b3fe4cbd58 ipvs: fix more places with wrong ipv6 transport offsets
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>
2026-07-10 16:28:47 +02:00
Florian Westphal
a2f57827bf ipvs: reload ip header after head reallocation
__ip_vs_get_out_rt() calls skb_ensure_writable() which may
reallocate skb->head.

Fixes: 8d8e20e2d7 ("ipvs: Decrement ttl")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-sonnet-4-6
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-07-10 16:28:47 +02:00
Julian Anastasov
3f7a535ff0 ipvs: ensure inner headers in ICMP errors are in headroom
Sashiko points out that after stripping the outer headers
with pskb_pull() we should ensure the inner IP headers
in ICMP errors from tunnels are present in the skb headroom
for functions like ipv4_update_pmtu(), icmp_send() and
IP_VS_DBG().

Also, add more checks for the length of the inner headers.

Fixes: f2edb9f770 ("ipvs: implement passive PMTUD for IPIP packets")
Link: https://sashiko.dev/#/patchset/20260702073430.67680-1-zhaoyz24%40mails.tsinghua.edu.cn
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-07-08 15:33:44 +02:00
Yizhou Zhao
2f75c0faa3 ipvs: use parsed transport offset in SCTP state lookup
set_sctp_state() reads the SCTP chunk header again in order to drive the
IPVS SCTP state table. For IPv6 it computes the offset with
sizeof(struct ipv6hdr), while the surrounding IPVS code uses iph.len from
ip_vs_fill_iph_skb(), where ipv6_find_hdr() has already skipped
extension headers and found the real transport header.

This makes the state machine read from the wrong offset for IPv6 SCTP
packets that carry extension headers. For example, an INIT packet with an
8-byte destination options header can be scheduled correctly by
sctp_conn_schedule(), but set_sctp_state() reads the first byte of the
SCTP verification tag as a DATA chunk type. The connection then moves
from NONE to ESTABLISHED instead of INIT1, gets the longer established
timeout, and updates the active/inactive destination counters
incorrectly. This happens even though the SCTP handshake has not
completed.

Use the parsed transport offset passed down from ip_vs_set_state() for
the SCTP chunk-header lookup. For IPv4 and IPv6 packets without
extension headers this preserves the existing offset.

Fixes: 2906f66a56 ("ipvs: SCTP Trasport Loadbalancing Support")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/netdev/20260705123040.35755-1-zhaoyz24@mails.tsinghua.edu.cn/
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>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-07-08 15:33:44 +02:00
Yizhou Zhao
2500fa3958 ipvs: use parsed transport offset in TCP state lookup
TCP state handling reparses the skb to find the TCP header. For IPv6 it
uses sizeof(struct ipv6hdr), while the surrounding IPVS code already
parsed the packet with ip_vs_fill_iph_skb() and has the real
transport-header offset in iph.len.

This makes TCP state handling look at the wrong bytes when an IPv6
packet carries extension headers. Use the parsed transport offset passed
down from ip_vs_set_state() when reading the TCP header.

For IPv4 and for IPv6 packets without extension headers, the passed
offset matches the previous value.

Fixes: 0bbdd42b7e ("IPVS: Extend protocol DNAT/SNAT and state handlers")
Link: https://lore.kernel.org/netdev/20260705125659.37744-1-zhaoyz24@mails.tsinghua.edu.cn/
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>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-07-08 15:33:44 +02:00
Yizhou Zhao
bae7ce7baf ipvs: pass parsed transport offset to state handlers
IPVS callers already parse the packet into struct ip_vs_iphdr before
updating connection state. For IPv6 this records the real
transport-header offset after extension headers in iph.len.

Pass this parsed transport offset through ip_vs_set_state() and the
protocol state_transition() callback so protocol handlers can use the
same packet context as scheduling and NAT handling. This patch only
changes the common callback plumbing and adapts the protocol callback
signatures; TCP and SCTP start using the value in follow-up patches.

Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-07-08 15:33:44 +02:00
Yizhou Zhao
2975324d16 ipvs: reset full ip_vs_seq structs in ip_vs_conn_new
Commit 9a05475ceb ("ipvs: avoid kmem_cache_zalloc in
ip_vs_conn_new") changed ip_vs_conn_new() to allocate an ip_vs_conn
object with kmem_cache_alloc().  The function then initializes many
fields explicitly, but only resets in_seq.delta and out_seq.delta in the
two struct ip_vs_seq members.

That leaves init_seq and previous_delta uninitialized.  This is normally
harmless while the corresponding IP_VS_CONN_F_IN_SEQ or
IP_VS_CONN_F_OUT_SEQ flag is clear.  For connections learned from a sync
message, however, ip_vs_proc_conn() preserves those flags from
IP_VS_CONN_F_BACKUP_MASK and passes opt=NULL when the message omits
IPVS_OPT_SEQ_DATA.  In that case the new connection can be hashed with
SEQ flags set but with the rest of in_seq/out_seq still containing stale
slab data.

When a packet for such a connection is later handled by an IPVS
application helper, vs_fix_seq() and vs_fix_ack_seq() use
previous_delta and init_seq to rewrite TCP sequence numbers.  A malformed
sync message can therefore make forwarded packets carry stale slab bytes
in their TCP seq/ack numbers, and can also corrupt the forwarded TCP
flow.

Reset both struct ip_vs_seq members completely before publishing the
connection.  This matches the existing "reset struct ip_vs_seq" comment
and keeps the sequence-adjustment gates inactive unless valid sequence
data is installed later.

Fixes: 9a05475ceb ("ipvs: avoid kmem_cache_zalloc in ip_vs_conn_new")
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>
2026-07-03 14:45:21 +02:00
Yizhou Zhao
6b335af0d0 ipvs: fix PMTU for GUE/GRE tunnel ICMP errors
When an ICMP Fragmentation Needed error is received for a tunneled IPVS
connection, ip_vs_in_icmp() recomputes the MTU that the original packet
can use by subtracting the tunnel overhead from the reported next-hop
MTU.

The current code always subtracts sizeof(struct iphdr), which is only
the IPIP overhead. For GUE and GRE tunnels, ipvs_udp_decap() and
ipvs_gre_decap() already compute the additional tunnel header length,
but that value is scoped to the decapsulation block and is lost before
the ICMP_FRAG_NEEDED handling. As a result, the ICMP error sent back to
the client advertises an MTU that is too large, so PMTUD can fail to
converge for GUE/GRE-tunneled real servers.

With a reported next-hop MTU of 1400, a GUE tunnel currently returns
1380 to the client. The correct value is 1368:

  1400 - sizeof(struct iphdr) - sizeof(struct udphdr) -
  sizeof(struct guehdr)

Hoist the tunnel header length into the main ip_vs_in_icmp() scope and
subtract sizeof(struct iphdr) + ulen in the Fragmentation Needed path.
The IPIP path keeps ulen as 0, so its existing 1400 - 20 = 1380 result
is unchanged.

Fixes: 508f744c0d ("ipvs: strip udp tunnel headers from icmp errors")
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>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-07-03 14:45:21 +02:00
Marco Crivellari
30877f3da9 ipvs: Replace use of system_unbound_wq with system_dfl_long_wq
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>
2026-06-14 12:49:32 +02:00
Julian Anastasov
4a15044a2b ipvs: add conn_max sysctl to limit connections
Currently, we are using atomic_t to track the number of
connections. On 64-bit setups with large memory there is
a risk this counter to overflow. Also, setups with many
containers may need to tune the limit for connections.

Add sysctl control to limit the number of connections to
1,073,741,824 (64-bit) and 16,777,216 (32-bit).
Depending on the admin's privilege, the value is
used to change a soft or hard limit allowing
unprivileged admins to change the soft limit in
range determined by privileged admins.

Link: https://sashiko.dev/#/patchset/20260523172715.94795-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260430074420.26697-7-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260522105546.13732-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:54 +02:00
Jakub Kicinski
8d72997dab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.1-rc7).

Silent conflicts:

net/wireless/nl80211.c
  cb9959ab5f ("wifi: cfg80211: enforce HE/EHT cap/oper consistency")
  a384ae9699 ("wifi: cfg80211: move AP HT/VHT/... operation to beacon info")
https://lore.kernel.org/aiGJDaHV4UlCexIQ@sirena.org.uk

Conflicts:

drivers/net/wireless/intel/iwlwifi/mld/ap.c
  a342c99cb7 ("wifi: iwlwifi: mld: honor BSS_CHANGED_BEACON_ENABLED")
  9bf1b409af ("wifi: iwlwifi: mld: send tx power constraints before link activation")
https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk

drivers/net/wireless/intel/iwlwifi/pcie/drv.c
  093305d801 ("wifi: iwlwifi: pcie: simplify the resume flow if fast resume is not used")
  e2323929a6 ("wifi: iwlwifi: pcie: add debug print for resume flow if powered off")
https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk

Adjacent changes:

drivers/net/ethernet/airoha/airoha_eth.c
  b38cae85d1 ("net: airoha: Fix use-after-free in metadata dst teardown")
  ec6c391bcc ("net: airoha: Introduce airoha_gdm_dev struct")

drivers/net/ethernet/microchip/lan743x_main.c
  8173d22b21 ("net: lan743x: permit VLAN-tagged packets up to configured MTU")
  e3c6508a46 ("net: lan743x: avoid netdev-based logging before netdev registration")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 15:29:04 -07:00
Julian Anastasov
193989cc6d ipvs: clear the svc scheduler ptr early on edit
ip_vs_edit_service() while unbinding the old scheduler clears
the svc->scheduler ptr after the scheduler module initiates
RCU callbacks. This can cause packets to use the old
scheduler at the time when svc->sched_data is already freed
after RCU grace period.

Fix it by clearing the ptr early in ip_vs_unbind_scheduler(),
before the done_service method schedules any RCU callbacks.

Also, if the new scheduler fails to initialize when replacing
the old scheduler, try to restore the old scheduler while still
returning the error code.

Link: https://sashiko.dev/#/patchset/20260519015506.634185-1-rosenp%40gmail.com
Fixes: 05f00505a8 ("ipvs: fix crash if scheduler is changed")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-01 13:43:52 +02:00
Florian Westphal
403cec8ab6 netfilter: add option for GCOV profiling
Similar to a few other subsystems: add a new config toggle to
enable netfilter gcov profiling in netfilter, including ebtables,
arptables and so on.

ipset and ipvs gain their own, dedicated toggles.

Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-05-24 22:55:47 +02:00
Julian Anastasov
5522d65d81 ipvs: avoid possible loop in ip_vs_dst_event on resizing
Sashiko points out that unprivileged user can frequently
call ip_vs_flush() or ip_vs_del_service() to trigger
svc_table_changes updates that can lead to infinite loop
in ip_vs_dst_event(). This can also happen if the user
triggers frequent table resizing without deleting all
services. We should also consider the possible effects
if the user triggers many NETDEV_DOWN events.

One way to solve it is to hold svc_resize_sem in
ip_vs_dst_event() but this can block the dev notifier
during the whole resizing process.

Instead, use new rw_semaphore svc_replace_sem to protect just
the svc_table replacement which is a short code section.
Then hold svc_replace_sem in ip_vs_dst_event() to serialize
with replacing the svc_table. As result, loop is avoided
as there is no need to repeat the table walking from the
start. By this way changes in svc_table_changes can happen
only when all services are removed and all dev references
dropped which allows us to abort the table walking.

As IP_VS_WORK_SVC_NORESIZE is the flag used to stop the
svc_resize_work under service_mutex, we should check only
this flag often but not while under service_mutex.

To remove the mutex_trylock() for service_mutex in the
second phase where the resizer installs the new table
after rehashing, we will avoid holding the service_mutex
there. As result, the code in configuration context which
is under service_mutex should access ipvs->svc_table under
RCU because it can be replaced at anytime and released
after a RCU grace period. As for ip_vs_zero_all(), it needs
different solution as a table walker which can escape
single RCU read-side critical section: to hold the
svc_replace_sem to prevent table to be replaced.

In ip_vs_status_show() prefer to hold svc_replace_sem
to avoid many loops, just detect if the svc_table is
removed.

Prefer the newly attached table for the u_thresh/l_thresh
checks to know when to grow/shrink while adding or deleting
services because the new table size is based on the latest
parameters.

Link: https://sashiko.dev/#/patchset/20260505001648.360569-1-pablo%40netfilter.org
Fixes: 840aac3d90 ("ipvs: use resizable hash table for services")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-16 12:19:56 +02:00
Waiman Long
aa60652069 ipvs: Guard access of HK_TYPE_KTHREAD cpumask with RCU
The ip_vs_ctl.c file and the associated ip_vs.h file are the only places
in the kernel where HK_TYPE_KTHREAD cpumask is being retrieved and used.
Now that HK_TYPE_KTHREAD/HK_TYPE_DOMAIN cpumask can be changed at run
time. We need to use RCU to guard access to this cpumask to avoid a
potential UAF problem as the returned cpumask may be freed before it
is being used.

We can replace HK_TYPE_KTHREAD by HK_TYPE_DOMAIN as they are aliases
of each other, but keeping the HK_TYPE_KTHREAD name can highlight the
fact that it is the kthread initiated by ipvs that is being controlled.

Fixes: 03ff735101 ("cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-05 01:52:55 +02:00
Julian Anastasov
4ee52b7021 ipvs: fix shift-out-of-bounds in ip_vs_rht_desired_size
Calling roundup_pow_of_two() with 0 has undefined result:

UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13
shift exponent 64 is too large for 64-bit type 'unsigned long'
CPU: 1 UID: 0 PID: 77 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound conn_resize_work_handler
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
 __ubsan_handle_shift_out_of_bounds+0x385/0x410 lib/ubsan.c:494
 __roundup_pow_of_two include/linux/log2.h:57 [inline]
 ip_vs_rht_desired_size+0x2cf/0x410 net/netfilter/ipvs/ip_vs_core.c:240
 ip_vs_conn_desired_size net/netfilter/ipvs/ip_vs_conn.c:765 [inline]
 conn_resize_work_handler+0x1b6/0x14c0 net/netfilter/ipvs/ip_vs_conn.c:822
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Reported-by: syzbot+217f1db9c791e27fe54a@syzkaller.appspotmail.com
Fixes: b655388111 ("ipvs: add resizable hash tables")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-05 01:52:55 +02:00
Julian Anastasov
2fd1092389 ipvs: fix races around est_mutex and est_cpulist
Sashiko reports for races and possible crash around
the usage of est_cpulist_valid and sysctl_est_cpulist.
The problem is that we do not lock est_mutex in some
places which can lead to wrong write ordering and
as result problems when calling cpumask_weight()
and cpumask_empty().

Fix them by moving the est_max_threads read/write under
locked est_mutex. Do the same for one ip_vs_est_reload_start()
call to protect the cpumask_empty() usage of sysctl_est_cpulist.

To remove the chance of deadlock while stopping the
estimation kthreads, keep the data structure for kthread 0
even after last estimator is removed and do not hold mutexes
while stopping this task. Now we will use a new flag 'needed'
to know when kthread 0 should run. The kthreads above 0
do not use mutexes, so stop them under est_mutex because
their kthread data still can be destroyed if they do not
serve estimators. Now all kthreads will be started by
the est_reload_work to properly serialize the stop/start
for kthread 0.

Reduce the use of service_mutex in ip_vs_est_calc_phase()
because under est_mutex we can safely walk est_kt_arr to
stop the kthreads above slot 0.

As ip_vs_stop_estimator() for tot_stats should be called
under service_mutex, do it early in the netns exit path
in ip_vs_flush() to avoid locking the mutex again later.
It still should be called in ip_vs_control_net_cleanup_sysctl()
when we are called during netns init error. Use -2 for ktid
as indicator if estimator was already stopped.

Finally, fix use-after-free for kd->est_row in
ip_vs_est_calc_phase(). est->ktrow should simply switch to
a delay value while estimator is linked to est_temp_list.

Link: https://sashiko.dev/#/patchset/20260331165015.2777765-1-longman%40redhat.com
Link: https://sashiko.dev/#/patchset/20260420171308.87192-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260422125123.40658-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260424175858.54752-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260425103918.7447-1-ja%40ssi.bg
Fixes: f0be83d542 ("ipvs: add est_cpulist and est_nice sysctl vars")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-05 01:52:55 +02:00
Julian Anastasov
fbe1e01e81 ipvs: do not leak dest after get from dest trash
Sashiko warns about leaked dest if ip_vs_start_estimator()
fails in ip_vs_add_dest(). Add ip_vs_trash_put_dest() to
put back the dest into dest trash.

Link: https://sashiko.dev/#/patchset/20260428175725.72050-1-ja%40ssi.bg
Fixes: 705dd34440 ("ipvs: use kthreads for stats estimation")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-05 01:52:55 +02:00
Julian Anastasov
d493d9de1c ipvs: fix the spin_lock usage for RT build
syzbot reports for sleeping function called from invalid context [1].
The recently added code for resizable hash tables uses
hlist_bl bit locks in combination with spin_lock for
the connection fields (cp->lock).

Fix the following problems:

* avoid using spin_lock(&cp->lock) under locked bit lock
because it sleeps on PREEMPT_RT

* as the recent changes call ip_vs_conn_hash() only for newly
allocated connection, the spin_lock can be removed there because
the connection is still not linked to table and does not need
cp->lock protection.

* the lock can be removed also from ip_vs_conn_unlink() where we
are the last connection user.

* the last place that is fixed is ip_vs_conn_fill_cport()
where now the cp->lock is locked before the other locks to
ensure other packets do not modify the cp->flags in non-atomic
way. Here we make sure cport and flags are changed only once
if two or more packets race to fill the cport. Also, we fill
cport early, so that if we race with resizing there will be
valid cport key for the hashing. Add a warning if too many
hash table changes occur for our RCU read-side critical
section which is error condition but minor because the
connection still can expire gracefully. Still, restore the
cport to 0 to allow retransmitted packet to properly fill
the cport. Problems reported by Sashiko.

[1]:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 16, name: ktimers/0
preempt_count: 2, expected: 0
RCU nest depth: 3, expected: 3
8 locks held by ktimers/0/16:
 #0: ffffffff8de5f260 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
 #1: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
 #2: ffff8880b8826360 (&base->expiry_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #2: ffff8880b8826360 (&base->expiry_lock){+...}-{3:3}, at: timer_base_lock_expiry kernel/time/timer.c:1502 [inline]
 #2: ffff8880b8826360 (&base->expiry_lock){+...}-{3:3}, at: __run_timer_base+0x120/0x9f0 kernel/time/timer.c:2384
 #3: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #3: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #3: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #3: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
 #4: ffffc90000157a80 ((&cp->timer)){+...}-{0:0}, at: call_timer_fn+0xd4/0x5e0 kernel/time/timer.c:1745
 #5: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #5: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #5: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: ip_vs_conn_unlink net/netfilter/ipvs/ip_vs_conn.c:315 [inline]
 #5: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: ip_vs_conn_expire+0x257/0x2390 net/netfilter/ipvs/ip_vs_conn.c:1260
 #6: ffffffff8de5f260 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
 #7: ffff888068d4c3f0 (&cp->lock#2){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #7: ffff888068d4c3f0 (&cp->lock#2){+...}-{3:3}, at: ip_vs_conn_unlink net/netfilter/ipvs/ip_vs_conn.c:324 [inline]
 #7: ffff888068d4c3f0 (&cp->lock#2){+...}-{3:3}, at: ip_vs_conn_expire+0xd4a/0x2390 net/netfilter/ipvs/ip_vs_conn.c:1260
Preemption disabled at:
[<ffffffff898a6358>] bit_spin_lock include/linux/bit_spinlock.h:38 [inline]
[<ffffffff898a6358>] hlist_bl_lock+0x18/0x110 include/linux/list_bl.h:149
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G        W    L      syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 __might_resched+0x329/0x480 kernel/sched/core.c:9162
 __rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline]
 rt_spin_lock+0xc2/0x400 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:45 [inline]
 ip_vs_conn_unlink net/netfilter/ipvs/ip_vs_conn.c:324 [inline]
 ip_vs_conn_expire+0xd4a/0x2390 net/netfilter/ipvs/ip_vs_conn.c:1260
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1151
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Reported-by: syzbot+504e778ddaecd36fdd17@syzkaller.appspotmail.com
Link: https://sashiko.dev/#/patchset/20260415200216.79699-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260420165539.85174-4-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260422135823.50489-4-ja%40ssi.bg
Fixes: 2fa7cc9c70 ("ipvs: switch to per-net connection table")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-05 01:52:55 +02:00
Julian Anastasov
f2da9a96ab ipvs: fix races around the conn_lfactor and svc_lfactor sysctl vars
Sashiko warns that the new sysctls vars can be changed
after the hash tables are destroyed and their respective
resizing works canceled, leading to mod_delayed_work()
being called for canceled works.

Solve this in different ways. conn_tab can be present even
without services and is destroyed only on netns exit, so use
disable_delayed_work_sync() to disable the work instead of
adding more synchronization mechanisms.

As for the svc_table, it is destroyed when the services
are deleted, so we must be sure that netns exit is not
called yet (the check for 'enable') and the work is
not canceled by checking all under same mutex lock.

Also, use WRITE_ONCE when updating the sysctl vars as we
already read them with READ_ONCE.

Link: https://sashiko.dev/#/patchset/20260410112352.23599-1-fw%40strlen.de
Fixes: 8d7de5477e ("ipvs: add conn_lfactor and svc_lfactor sysctl vars")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-05 01:52:55 +02:00
Julian Anastasov
afbd961305 ipvs: fixes for the new ip_vs_status info
Sashiko reports some problems for the recently added
/proc/net/ip_vs_status:

* ip_vs_status_show() as a table reader may run long after the
conn_tab and svc_table table are released. While ip_vs_conn_flush()
properly changes the conn_tab_changes counter when conn_tab is removed,
ip_vs_del_service() and ip_vs_flush() were missing such change for
the svc_table_changes counter. As result, readers like
ip_vs_dst_event() and ip_vs_status_show() may continue to use
a freed table after a cond_resched_rcu() call.

* While counting the buckets in ip_vs_status_show() make sure we
traverse only the needed number of entries in the chain. This also
prevents possible overflow of the 'count' variable.

* Add check for 'loops' to prevent infinite loops while restarting
the traversal on table change.

* While IP_VS_CONN_TAB_MAX_BITS is 20 on 32-bit platforms and
there is no risk to overflow when multiplying the number of
conn_tab buckets to 100, prefer the div_u64() helper to make
the following dividing safer.

* Use 0440 permissions for ip_vs_status to restrict the
info only to root due to the exported information for hash
distribution.

Link: https://sashiko.dev/#/patchset/20260410112352.23599-1-fw%40strlen.de
Fixes: 9a9ccef907 ("ipvs: add ip_vs_status info")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-05-05 01:52:55 +02:00
Yingnan Zhang
67bf42cae4 ipvs: fix MTU check for GSO packets in tunnel mode
Currently, IPVS skips MTU checks for GSO packets by excluding them with
the !skb_is_gso(skb) condition. This creates problems when IPVS tunnel
mode encapsulates GSO packets with IPIP headers.

The issue manifests in two ways:

1. MTU violation after encapsulation:
   When a GSO packet passes through IPVS tunnel mode, the original MTU
   check is bypassed. After adding the IPIP tunnel header, the packet
   size may exceed the outgoing interface MTU, leading to unexpected
   fragmentation at the IP layer.

2. Fragmentation with problematic IP IDs:
   When net.ipv4.vs.pmtu_disc=1 and a GSO packet with multiple segments
   is fragmented after encapsulation, each segment gets a sequentially
   incremented IP ID (0, 1, 2, ...). This happens because:

   a) The GSO packet bypasses MTU check and gets encapsulated
   b) At __ip_finish_output, the oversized GSO packet is split into
      separate SKBs (one per segment), with IP IDs incrementing
   c) Each SKB is then fragmented again based on the actual MTU

   This sequential IP ID allocation differs from the expected behavior
   and can cause issues with fragment reassembly and packet tracking.

Fix this by properly validating GSO packets using
skb_gso_validate_network_len(). This function correctly validates
whether the GSO segments will fit within the MTU after segmentation. If
validation fails, send an ICMP Fragmentation Needed message to enable
proper PMTU discovery.

Fixes: 4cdd34084d ("netfilter: nf_conntrack_ipv6: improve fragmentation handling")
Signed-off-by: Yingnan Zhang <342144303@qq.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20 23:45:43 +02:00
Julian Anastasov
8d7de5477e ipvs: add conn_lfactor and svc_lfactor sysctl vars
Allow the default load factor for the connection and service tables
to be configured.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10 12:16:26 +02:00
Julian Anastasov
9a9ccef907 ipvs: add ip_vs_status info
Add /proc/net/ip_vs_status to show current state of IPVS.

The motivation for this new /proc interface is to provide the output
for the users to help them decide when to tune the load factor for
hash tables, which is possible with the new sysctl knobs coming in
followup patch.

The output also includes information for the kthreads used for stats.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10 12:16:25 +02:00
Julian Anastasov
22e620fe84 ipvs: show the current conn_tab size to users
As conn_tab is per-net, better to show the current hash table size
to users instead of the ip_vs_conn_tab_size (max).

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10 12:16:25 +02:00
Jakub Kicinski
b6e39e4846 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.0-rc8).

Conflicts:

net/ipv6/seg6_iptunnel.c
  c3812651b5 ("seg6: separate dst_cache for input and output paths in seg6 lwtunnel")
  78723a62b9 ("seg6: add per-route tunnel source address")
https://lore.kernel.org/adZhwtOYfo-0ImSa@sirena.org.uk

net/ipv4/icmp.c
  fde29fd934 ("ipv4: icmp: fix null-ptr-deref in icmp_build_probe()")
  d98adfbdd5 ("ipv4: drop ipv6_stub usage and use direct function calls")
https://lore.kernel.org/adO3dccqnr6j-BL9@sirena.org.uk

Adjacent changes:

drivers/net/ethernet/stmicro/stmmac/chain_mode.c
  51f4e090b9 ("net: stmmac: fix integer underflow in chain mode")
  6b4286e055 ("net: stmmac: rename STMMAC_GET_ENTRY() -> STMMAC_NEXT_ENTRY()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-09 13:20:59 -07:00
Weiming Shi
9a91797e61 ipvs: fix NULL deref in ip_vs_add_service error path
When ip_vs_bind_scheduler() succeeds in ip_vs_add_service(), the local
variable sched is set to NULL.  If ip_vs_start_estimator() subsequently
fails, the out_err cleanup calls ip_vs_unbind_scheduler(svc, sched)
with sched == NULL.  ip_vs_unbind_scheduler() passes the cur_sched NULL
check (because svc->scheduler was set by the successful bind) but then
dereferences the NULL sched parameter at sched->done_service, causing a
kernel panic at offset 0x30 from NULL.

 Oops: general protection fault, [..] [#1] PREEMPT SMP KASAN NOPTI
 KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
 RIP: 0010:ip_vs_unbind_scheduler (net/netfilter/ipvs/ip_vs_sched.c:69)
 Call Trace:
  <TASK>
  ip_vs_add_service.isra.0 (net/netfilter/ipvs/ip_vs_ctl.c:1500)
  do_ip_vs_set_ctl (net/netfilter/ipvs/ip_vs_ctl.c:2809)
  nf_setsockopt (net/netfilter/nf_sockopt.c:102)
  [..]

Fix by simply not clearing the local sched variable after a successful
bind.  ip_vs_unbind_scheduler() already detects whether a scheduler is
installed via svc->scheduler, and keeping sched non-NULL ensures the
error path passes the correct pointer to both ip_vs_unbind_scheduler()
and ip_vs_scheduler_put().

While the bug is older, the problem popups in more recent kernels (6.2),
when the new error path is taken after the ip_vs_start_estimator() call.

Fixes: 705dd34440 ("ipvs: use kthreads for stats estimation")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Acked-by: Simon Horman <horms@kernel.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08 13:33:28 +02:00
Julian Anastasov
f20c73b046 ipvs: use more keys for connection hashing
Simon Kirby reported long time ago that IPVS connection hashing
based only on the client address/port (caddr, cport) as hash keys
is not suitable for setups that accept traffic on multiple virtual
IPs and ports. It can happen for multiple VIP:VPORT services, for
single or many fwmark service(s) that match multiple virtual IPs
and ports or even for passive FTP with peristence in DR/TUN mode
where we expect traffic on multiple ports for the virtual IP.

Fix it by adding virtual addresses and ports to the hash function.
This causes the traffic from NAT real servers to clients to use
second hashing for the in->out direction.

As result:

- the IN direction from client will use hash node hn0 where
the source/dest addresses and ports used by client will be used
as hash keys

- the OUT direction from NAT real servers will use hash node hn1
for the traffic from real server to client

- the persistence templates are hashed only with parameters based on
the IN direction, so they now will also use the virtual address,
port and fwmark from the service.

OLD:
- all methods: c_list node: proto, caddr:cport
- persistence templates: c_list node: proto, caddr_net:0
- persistence engine templates: c_list node: per-PE, PE-SIP uses jhash

NEW:
- all methods: hn0 node (dir 0): proto, caddr:cport -> vaddr:vport
- MASQ method: hn1 node (dir 1): proto, daddr:dport -> caddr:cport
- persistence templates: hn0 node (dir 0):
  proto, caddr_net:0 -> vaddr:vport_or_0
  proto, caddr_net:0 -> fwmark:0
- persistence engine templates: hn0 node (dir 0): as before

Also reorder the ip_vs_conn fields, so that hash nodes are on same
read-mostly cache line while write-mostly fields are on separate
cache line.

Reported-by: Simon Kirby <sim@hostway.ca>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-04 11:45:45 +01:00
Julian Anastasov
2fa7cc9c70 ipvs: switch to per-net connection table
Use per-net resizable hash table for connections. The global table
is slow to walk when using many namespaces.

The table can be resized in the range of [256 - ip_vs_conn_tab_size].
Table is attached only while services are present. Resizing is done
by delayed work based on load (the number of connections).

Add a hash_key field into the connection to store the table ID in
the highest bit and the entry's hash value in the lowest bits. The
lowest part of the hash value is used as bucket ID, the remaining
part is used to filter the entries in the bucket before matching
the keys and as result, helps the lookup operation to access only
one cache line. By knowing the table ID and bucket ID for entry,
we can unlink it without calculating the hash value and doing
lookup by keys. We need only to validate the saved hash_key under
lock.

For better security switch from jhash to siphash for the default
connection hashing but the persistence engines may use their own
function. Keeping the hash table loaded with entries below the
size (12%) allows to avoid collision for 96+% of the conns.

ip_vs_conn_fill_cport() now will rehash the connection with proper
locking because unhash+hash is not safe for RCU readers.

To invalidate the templates setting just dport to 0xffff is enough,
no need to rehash them. As result, ip_vs_conn_unhash() is now
unused and removed.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-04 11:45:45 +01:00
Julian Anastasov
840aac3d90 ipvs: use resizable hash table for services
Make the hash table for services resizable in the bit range of 4-20.
Table is attached only while services are present. Resizing is done
by delayed work based on load (the number of hashed services).
Table grows when load increases 2+ times (above 12.5% with lfactor=-3)
and shrinks 8+ times when load decreases 16+ times (below 0.78%).

Switch to jhash hashing to reduce the collisions for multiple
services.

Add a hash_key field into the service to store the table ID in
the highest bit and the entry's hash value in the lowest bits. The
lowest part of the hash value is used as bucket ID, the remaining
part is used to filter the entries in the bucket before matching
the keys and as result, helps the lookup operation to access only
one cache line. By knowing the table ID and bucket ID for entry,
we can unlink it without calculating the hash value and doing
lookup by keys. We need only to validate the saved hash_key under
lock.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-04 11:45:45 +01:00
Julian Anastasov
b655388111 ipvs: add resizable hash tables
Add infrastructure for resizable hash tables based on hlist_bl
which we will use in followup patches.

The tables allow RCU lookups during resizing, bucket modifications
are protected with per-bucket bit lock and additional custom locking,
the tables are resized when load reaches thresholds determined based
on load factor parameter.

Compared to other implementations we rely on:
* fast entry removal by using node unlinking without pre-lookup
* entry rehashing when hash key changes
* entries can contain multiple hash nodes
* custom locking depending on different contexts
* adjustable load factor to customize the grow/shrink process

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-03-04 11:45:45 +01:00
Jakub Kicinski
0314e382cf Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.0-rc2).

Conflicts:

tools/testing/selftests/drivers/net/hw/rss_ctx.py
  19c3a2a81d ("selftests: drv-net: rss: Generate unique ports for RSS context tests")
  ce5a0f4612 ("selftests: drv-net: rss_ctx: test RSS contexts persist after ifdown/up")

include/net/inet_connection_sock.h
  858d2a4f67 ("tcp: fix potential race in tcp_v6_syn_recv_sock()")
  fcd3d039fa ("tcp: make tcp_v{4,6}_send_check() static")
https://lore.kernel.org/aZ8PSFLzBrEU3I89@sirena.org.uk

drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
drivers/net/ethernet/mellanox/mlx5/core/en/xsk/pool.c
  69050f8d6d ("treewide: Replace kmalloc with kmalloc_obj for non-scalar types")
  bf4afc53b7 ("Convert 'alloc_obj' family to use the new default GFP_KERNEL argument")
  8a96b9144f ("net/mlx5e: Alloc xsk channel param out of mlx5e_open_xsk()")

Adjacent changes:

net/netfilter/ipvs/ip_vs_ctl.c
  c59bd9e62e ("ipvs: use more counters to avoid service lookups")
  bf4afc53b7 ("Convert 'alloc_obj' family to use the new default GFP_KERNEL argument")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-26 10:23:00 -08:00
Julian Anastasov
09b71fb459 ipvs: no_cport and dropentry counters can be per-net
Change the no_cport counters to be per-net and address family.
This should reduce the extra conn lookups done during present
NO_CPORT connections.

By changing from global to per-net dropentry counters, one net
will not affect the drop rate of another net.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20260224205048.4718-7-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-25 19:36:26 -08:00
Julian Anastasov
c59bd9e62e ipvs: use more counters to avoid service lookups
When new connection is created we can lookup for services multiple
times to support fallback options. We already have some counters
to skip specific lookups because it costs CPU cycles for hash
calculation, etc.

Add more counters for fwmark/non-fwmark services (fwm_services and
nonfwm_services) and make all counters per address family.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20260224205048.4718-6-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-25 19:36:26 -08:00
Julian Anastasov
40fb72209f ipvs: do not keep dest_dst after dest is removed
Before now dest->dest_dst is not released when server is moved into
dest_trash list after removal. As result, we can keep dst/dev
references for long time without actively using them.

It is better to avoid walking the dest_trash list when
ip_vs_dst_event() receives dev events. So, make sure we do not
hold dev references in dest_trash list. As packets can be flying
while server is being removed, check the IP_VS_DEST_F_AVAILABLE
flag in slow path to ensure we do not save new dev references to
removed servers.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20260224205048.4718-5-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-25 19:36:26 -08:00
Julian Anastasov
b24ae1a387 ipvs: use single svc table
fwmark based services and non-fwmark based services can be hashed
in same service table. This reduces the burden of working with two
tables.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20260224205048.4718-4-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-25 19:36:25 -08:00