laptop-kernel/net/netfilter/ipvs, branch master

ipvs: filter some flags received in the backup server

2026-09-30T07:35:20Z

While the IPVS SYNC protocol is not secure by design we can still protect the backup server from messages that can wreak havoc. This commit addresses problems from received connection flags or their combinations. We now drop messages as follows: 1. the NO_CPORT+TEMPLATE combination allows lookups for normal connections to hit template which can break in many ways. While the master does not sync connections with NO_CPORT flag, i.e. before they are established, we still accept NO_CPORT without TEMPLATE. 2. ONE_PACKET: it is not sent by master, so we do not expect it in backup. Before now it was ignored by IP_VS_CONN_F_BACKUP_MASK for protocol v1 while protocol v0 created connections that are not hashed and dropped immediately. Better to apply the IP_VS_CONN_F_BACKUP_MASK also to the flags from v0 messages for consistency with v1. Fixes: 87375ab47cd0 ("[IPVS]: ip_vs_ftp breaks connections using persistence") Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

ipvs: do not create invisible templates

2026-09-30T07:35:20Z

The IP_VS_CONN_F_ONE_PACKET flag was implemented for normal connections. When conn template inherits this flag from dest->conn_flags it will not be hashed. As result, we will create new template for every new normal connection. Fix it to allow one template to be used by many normal connections. Fixes: 26ec037f9841 ("IPVS: one-packet scheduling") Link: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260916231652.127456-1-pablo%40netfilter.org Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

ipvs: bound LBLCR and LBLC cache growth

2026-09-30T07:35:20Z

ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for every previously unseen destination address. The table max_size only tells the periodic collector to reclaim entries after the cache has already exceeded the limit. It does not reclaim entries that the attacker continues to use. Reject new cache entries once either table reaches max_size * 3 / 2. The extra headroom lets the periodic collector catch up while the existing scheduler fallback continues to use the selected destination when cache creation fails. New traffic therefore stays serviceable without growing the tables further. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Vega Suggested-by: Julian Anastasov Signed-off-by: Zhiling Zou Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

ipvs: fix missing counter decrement in lblc

2026-09-30T07:35:20Z

LBLC may delete cache entries for destinations that are removed or overloaded and replace them with available ones. But ip_vs_lblc_new() forgets to decrement the tbl->entries counter after calling ip_vs_lblc_del(). This can lead to increased shrinking of the cache with every new garbage collection. Fixes: 2f3d771a35fe ("ipvs: do not use dest after ip_vs_dest_put in LBLC") Link: https://sashiko.dev/#/patchset/0bdd5abe9968ded7ca2b9cb6844ba83d94cc8d53.1787318053.git.zhilinz%40nebusec.ai Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

ipvs: revalidate ihl before icmp_send

2026-09-18T08:58:07Z

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 possible out-of-bounds access. One such place reported by Sashiko is ip_vs_in_icmp() where local process can change the ihl field and after pskb_may_pull() we can see larger value. Even if icmp_send() has checks to prevent out-of-bounds access, play safe and add check to drop the packet if the ihl field is changed. As the outer headers are pulled, make sure the transport header is updated too, it was used before commit 7fcc2fe39fed ("net: icmp: avoid invalid transport header access in icmp_send tracepoint") Fixes: f2edb9f7706d ("ipvs: implement passive PMTUD for IPIP packets") Link: https://sashiko.dev/#/patchset/20260806105211.34622-1-ja%40ssi.bg Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

ipvs: fix reversed sequence option serialization

2026-09-02T23:39:27Z

hton_seq() expects the host-order source first and the unaligned network-order destination second. The version 1 sync sender passes these arguments in reverse for both sequence blocks. This leaves 24 bytes of the kmalloc-backed message unwritten. It may disclose stale heap data and replace the live connection sequence state with values read from the buffer. Pass the connection sequence state as the source and the message payload as the destination for both blocks. Fixes: 986a07579533 ("IPVS: Backup, Change sending to Version 1 format") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Kyle Zeng Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

ipvs: reject invalid states in connection template sync records

2026-09-02T23:39:27Z

IPVS sync receivers validate protocol states before creating or updating a connection. For connection templates, however, they only log states outside the template state range and still store the value in the connection. A template can be returned by ordinary connection lookup. TCP and SCTP then use the invalid state as an index into their transition tables. Reject invalid template states in both sync protocol versions before looking up or modifying a connection. The version 1 path handles both IPv4 and IPv6 records. Fixes: 275411430f89 ("ipvs: add assured state for conn templates") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Kyle Zeng Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

ipvs: fix integer overflow in ftp helper port/address parsing

2026-08-17T22:56:43Z

ip_vs_ftp_get_addrport() accumulates decimal digits into a __u16 (hport) and into unsigned char (p[]) without checking for overflow. A crafted FTP PASV/EPSV response with an over-long port or address octet wraps the value, so the helper configures the data connection with a truncated port/address. The netfilter conntrack FTP helper had the same defect, fixed in commit 2b413fc689ba ("netfilter: nf_conntrack_ftp: avoid u16 overflows"). Apply the equivalent fix here: widen the port accumulator to u32 and reject values above 65535, and reject address octets above 255. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Joas Antonio dos Santos Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-08-13T18:00:14Z

Cross-merge networking fixes after downstream PR (net-7.2-rc8). No conflicts. Adjacent changes: drivers/net/ethernet/wangxun/ngbe/ngbe_main.c 5f3a13e0bb5e ("net: ngbe: fix NULL pointer dereference in non-MSI-X interrupt enabling") d661abdc30c2 ("net: ngbe: correct misleading interrupt comment") drivers/net/ipvlan/ipvlan_main.c e16e960d55a4 ("ipvlan: inherit needed_headroom and needed_tailroom from phy_dev") 00a40d809207 ("ipvlan: Support per-netns netdev unregistration.") Signed-off-by: Jakub Kicinski

ipvs: revalidate ihl to prevent out-of-bounds access

2026-08-10T18:27:15Z

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: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://sashiko.dev/#/patchset/20260730183506.87473-1-ja%40ssi.bg Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso