linux-stable.git/include/net/ip_vs.h, branch v7.1.9

ipvs: separate destination availability state

2026-08-19T16:20:23+00:00

commit cdcc4e46180df8161f4d2f3c6fd6beaf6990133d upstream.

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao 
Reported-by: Yuxiang Yang 
Reported-by: Ao Wang 
Reported-by: Xuewei Feng 
Reported-by: Qi Li 
Reported-by: Ke Xu 
Link: https://lore.kernel.org/all/8913381c-1e02-35c7-0ec4-61de5a12fd35@ssi.bg/
Assisted-by: Claude-Code:GLM-5.2
Suggested-by: Julian Anastasov 
Signed-off-by: Yizhou Zhao 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

ipvs: properly update the overload flag on dest edit

2026-08-19T16:20:23+00:00

commit 8f843441c4e7eae8ea83491e8c203c2b192edcf5 upstream.

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Julian Anastasov 
Signed-off-by: Yizhou Zhao 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

ipvs: add totalconns for dest

2026-08-19T16:20:23+00:00

commit 04d2feaed8d0103c498727191ba04001d5100e67 upstream.

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Julian Anastasov 
Signed-off-by: Yizhou Zhao 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

ipvs: return the csum validation for forward hook

2026-08-19T16:20:15+00:00

[ Upstream commit 99609cb0aa789c8d071050ce8579989551882cc6 ]

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: e876b75b9020 ("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 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: avoid out-of-bounds write in ip_vs_nat_icmp

2026-08-19T16:20:15+00:00

[ Upstream commit 646922a0379496154e8c8faca4f8e2fd9100cacc ]

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260722101517.36313-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: do not mangle ICMP replies for non-first fragments

2026-08-09T18:26:27+00:00

[ Upstream commit 342e24a339b90e8e339a0f8c151ca479b8565661 ]

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260720201122.79882-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: fix places with wrong packet offsets

2026-08-09T18:26:27+00:00

[ Upstream commit 15cab31a3730e05f0767b922a7450e5d784b2607 ]

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260710143733.29741-2-fw%40strlen.de
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: fix the checksum validations

2026-08-09T18:26:27+00:00

[ Upstream commit e876b75b9020a97bbdc79721e7fc749024891c65 ]

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: 2a3b791e6e11 ("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 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: pass parsed transport offset to state handlers

2026-07-24T14:20:45+00:00

[ Upstream commit bae7ce7bafb59e42dc0e0e2999fdd9d1cffe3866 ]

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 
Acked-by: Julian Anastasov 
Signed-off-by: Florian Westphal 
Stable-dep-of: 2500fa3958b1 ("ipvs: use parsed transport offset in TCP state lookup")
Signed-off-by: Sasha Levin

ipvs: clear the svc scheduler ptr early on edit

2026-06-01T11:43:52+00:00

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: 05f00505a89a ("ipvs: fix crash if scheduler is changed")
Signed-off-by: Julian Anastasov 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso