kernel/linux.git/net/ipv6, branch v6.18.43

netfilter: nf_tables: remove register tracking infrastructure

2026-08-03T09:22:09+00:00

[ Upstream commit 6b94d081f81dd524626f7aab2b98a9de335edb72 ] This facility was disabled in commit 9e539c5b6d9c ("netfilter: nf_tables: disable expression reduction infra"), because not all nft_exprs guarantee they will update the destination register: some may set NFT_BREAK instead to cancel evaluation of the rule. This has been dead code ever since. There are no plans to salvage this at this time, so remove this. Signed-off-by: Florian Westphal Link: https://patch.msgid.link/20260224205048.4718-10-fw@strlen.de Signed-off-by: Jakub Kicinski Stable-dep-of: d07955dd34ec ("netfilter: nft_fib: reject fib expression on the netdev egress hook") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

tcp: initialize standalone TCP-AO response padding

2026-08-03T09:22:05+00:00

commit e1a9d3cc11829c5414a75eb39c704f461936eb24 upstream. tcp_v4_send_ack() and tcp_v6_send_response() construct standalone TCP responses with TCP-AO options. The option length carries the actual MAC length, but the TCP header length includes the option rounded up to a four-byte boundary. tcp_ao_hash_hdr() writes the MAC only. Thus, when the MAC length is not four-byte aligned, the one to three bytes after the MAC are left uninitialized and may be transmitted. For the normal TCP-AO hashing mode, those bytes also have to be initialized before computing the MAC. Initialize only the alignment padding in the TCP-AO branches, before hashing the header. Use TCPOPT_NOP, as in the normal TCP-AO output path. This avoids adding work to non-AO TCP responses while preserving a valid authenticated header. Fixes: decde2586b34 ("net/tcp: Add TCP-AO sign to twsk") Fixes: da7dfaa6d6f7 ("net/tcp: Consistently align TCP-AO option in the header") 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 Suggested-by: Eric Dumazet Signed-off-by: Yizhou Zhao Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260713105631.8616-1-zhaoyz24@mails.tsinghua.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ila: reload IPv6 header after pskb_may_pull in checksum adjust

2026-08-03T09:22:04+00:00

commit 92d3817649df2b0b6a008a686c8275c88d7ef594 upstream. ila_csum_adjust_transport() caches ip6h = ipv6_hdr(skb) before calling pskb_may_pull(). On a non-linear skb whose transport header sits in a page fragment, pskb_may_pull() can call __pskb_pull_tail() / pskb_expand_head() and free the old skb head, leaving ip6h dangling; the following get_csum_diff(ip6h, p) then reads freed memory. ila_update_ipv6_locator() uses ip6h (and the iaddr derived from it) again after the csum-adjust call and additionally writes the new locator through that pointer. Impact: a remote IPv6 packet routed through a configured ILA csum-adjust-transport route or receive-side mapping triggers a slab-use-after-free in ila_update_ipv6_locator() (KASAN). The route or mapping requires CAP_NET_ADMIN to configure, but trigger packets are unauthenticated once it exists. Reload ip6h after each pskb_may_pull() in ila_csum_adjust_transport() before the csum-diff read. In ila_update_ipv6_locator() only the ILA_CSUM_ADJUST_TRANSPORT case pulls the skb, so reload ip6h and iaddr in that case alone before the destination-address write; the neutral-map modes never pull and keep their cached pointers. Fixes: 33f11d16142b ("ila: Create net/ipv6/ila directory") Cc: stable@vger.kernel.org Signed-off-by: Michael Bommarito Reviewed-by: Simon Horman Reviewed-by: Antoine Tenart Link: https://patch.msgid.link/20260714114903.3763420-1-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ipv6: Change allocation flags to match rcu_read_lock section requirements

2026-08-03T09:21:47+00:00

[ Upstream commit 313a123e1fca8827bb463db1f4bb211309764563 ] Since the call to __ip6_del_rt_siblings has been converted under rcu read lock and it only has one call point we should no longer block or yield. Our stack trace from the syzbot reproducer looks as follows: __ip6_del_rt_siblings rtnl_notify (Here we pass gfp_any() -> GFP_KERNEL) nlmsg_notify nlmsg_multicast nlmsg_multicast_filtered netlink_broadcast_filtered (GFP_KERNEL passed from earlier) netlink_broadcast_filtered can yield if GFP_KERNEL is passed, which we do not want to happen. Fix this by changing the allocation flag of rtnl_notify. Also change the flag passed to nlmsg_new. Even though it is not related to the syzbot generated bug it still falls under the same requirements. Reported-by: syzbot+84d4a405ed798b40c96d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=84d4a405ed798b40c96d Fixes: bd11ff421d36 ("ipv6: Get rid of RTNL for SIOCDELRT and RTM_DELROUTE.") Signed-off-by: Nikola Z. Ivanov Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260719105759.558050-1-zlatistiv@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: ipv6: fix dif and sdif mismatch in raw6_icmp_error

2026-08-03T09:21:47+00:00

[ Upstream commit 440e274da4d1b93c7df2cb0ce893c3009dd4db55 ] In raw6_icmp_error(), raw_v6_match() is called with inet6_iif(skb) passed to both the 'dif' and 'sdif' arguments. This is a copy-paste or typo error, as the last argument should represent the secondary interface index (sdif). This mismatch breaks ICMPv6 error handling for IPv6 raw sockets in VRF (Virtual Routing and Forwarding) environments. When a raw socket is bound to a VRF master device, raw_v6_match() fails to find a match because it is not given the correct sdif value, causing the socket to miss relevant ICMPv6 error notifications. Fix this by properly passing inet6_sdif(skb) as the last argument to raw_v6_match(). Fixes: 5108ab4bf446fa ("net: ipv6: add second dif to raw socket lookups") Signed-off-by: Li RongQing Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260717143230.1836-1-lirongqing@baidu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: gre: fix lltx regression for GRE tunnels with SEQ/CSUM

2026-08-03T09:21:46+00:00

[ Upstream commit 675ed582c1aa4d919dd535490de08c015005c653 ] Before commit 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev->lltx"), NETIF_F_LLTX was set unconditionally in both __gre_tunnel_init() and ip6gre_tnl_init_features() alongside GRE_FEATURES: dev->features |= GRE_FEATURES | NETIF_F_LLTX; When that commit converted NETIF_F_LLTX to the dev->lltx flag, it placed 'dev->lltx = true' after the SEQ/CSUM early returns instead of before them. This causes GRE/GRETAP/ip6gre tunnels with SEQ or CSUM+encap to lose lockless TX, reintroducing _xmit_lock acquisition around their ndo_start_xmit. Since GRE xmit re-enters the stack via ip_tunnel_xmit(), holding _xmit_lock risks ABBA deadlock with the underlay device. CPU0 CPU1 ---- ---- lock(&qdisc_xmit_lock_key#6); lock(&qdisc_xmit_lock_key#3); lock(&qdisc_xmit_lock_key#6); lock(&qdisc_xmit_lock_key#3); Fix by moving dev->lltx = true before the early returns in both functions, restoring the original unconditional behavior. Fixes: 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev->lltx") Signed-off-by: Yun Zhou Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260713150945.1779628-1-yun.zhou@windriver.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

tcp: fix TIME_WAIT socket reference leak on PSP policy failure

2026-08-03T09:21:35+00:00

[ Upstream commit 2c1931a81122c3cdc4c89448fe0442c69e21c0d5 ] Release the TIME_WAIT socket reference and jump to discard_it upon PSP policy failure in both IPv4 and IPv6 receive paths. This prevents a memory leak of tcp_tw_bucket structures. Fixes: 659a2899a57d ("tcp: add datapath logic for PSP with inline key exchange") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Reviewed-by: Daniel Zahka Link: https://patch.msgid.link/20260710181317.4060230-1-edumazet@google.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()

2026-08-03T09:21:29+00:00

[ Upstream commit 136992de9bb91871084ae52d172610541c76e4d2 ] On the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst() releases the device reference with netdev_put() but leaves xdst->u.dst.dev set. dst_destroy() later calls netdev_put(dst->dev) again, so the same net_device reference is released twice, underflowing its refcount (ref_tracker WARNING + "unregister_netdevice: waiting for to become free"). Clear xdst->u.dst.dev after the netdev_put(), the same way the XFRM device-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in net/xfrm/xfrm_device.c NULL ->dev when releasing the reference on error. ref_tracker: reference already released. ref_tracker: allocated in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86) ... udpv6_sendmsg (net/ipv6/udp.c:1696) ... ref_tracker: freed in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90) ... WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780 dst_destroy (net/core/dst.c:115) rcu_core handle_softirqs ... Fixes: 84c4a9dfbf43 ("xfrm6: release dev before returning error") Reported-by: AutonomousCodeSecurity@microsoft.com Signed-off-by: Xiang Mei (Microsoft) Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink

2026-07-24T14:17:12+00:00

commit 2496fa0b7d180b3ad356b514e7ff93bb14e6140a upstream. ip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Gate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed. Reported-by: Xiao Liang Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/ Fixes: 0bd8762824e7 ("ip6tnl: add x-netns support") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260612085941.3158249-5-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: ip6_gre: require CAP_NET_ADMIN in the device netns for changelink

2026-07-24T14:17:12+00:00

commit f00a50876d2818bd6dc86fa98b3ef360884c53c8 upstream. ip6gre_changelink() and ip6erspan_changelink() operate on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Gate both ops on rtnl_dev_link_net_capable() at their top, before any attribute is parsed. Reported-by: Xiao Liang Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/ Fixes: 690afc165bb3 ("net: ip6_gre: fix moving ip6gre between namespaces") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260612085941.3158249-6-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman