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2026-04-05mm/memory: remove "zap_details" parameter from zap_page_range_single()David Hildenbrand (Arm)
Nobody except memory.c should really set that parameter to non-NULL. So let's just drop it and make unmap_mapping_range_vma() use zap_page_range_single_batched() instead. [david@kernel.org: format on a single line] Link: https://lkml.kernel.org/r/8a27e9ac-2025-4724-a46d-0a7c90894ba7@kernel.org Link: https://lkml.kernel.org/r/20260227200848.114019-3-david@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Puranjay Mohan <puranjay@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Arve <arve@android.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Dave Airlie <airlied@gmail.com> Cc: David Ahern <dsahern@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hartley Sweeten <hsweeten@visionengravers.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ian Abbott <abbotti@mev.co.uk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jakub Kacinski <kuba@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Namhyung kim <namhyung@kernel.org> Cc: Neal Cardwell <ncardwell@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Todd Kjos <tkjos@android.com> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-03ipv4: icmp: fix null-ptr-deref in icmp_build_probe()Yiqi Sun
ipv6_stub->ipv6_dev_find() may return ERR_PTR(-EAFNOSUPPORT) when the IPv6 stack is not active (CONFIG_IPV6=m and not loaded), and passing this error pointer to dev_hold() will cause a kernel crash with null-ptr-deref. Instead, silently discard the request. RFC 8335 does not appear to define a specific response for the case where an IPv6 interface identifier is syntactically valid but the implementation cannot perform the lookup at runtime, and silently dropping the request may safer than misreporting "No Such Interface". Fixes: d329ea5bd884 ("icmp: add response to RFC 8335 PROBE messages") Signed-off-by: Yiqi Sun <sunyiqixm@gmail.com> Link: https://patch.msgid.link/20260402070419.2291578-1-sunyiqixm@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03ipv4: nexthop: allocate skb dynamically in rtm_get_nexthop()Fernando Fernandez Mancera
When querying a nexthop object via RTM_GETNEXTHOP, the kernel currently allocates a fixed-size skb using NLMSG_GOODSIZE. While sufficient for single nexthops and small Equal-Cost Multi-Path groups, this fixed allocation fails for large nexthop groups like 512 nexthops. This results in the following warning splat: WARNING: net/ipv4/nexthop.c:3395 at rtm_get_nexthop+0x176/0x1c0, CPU#20: rep/4608 [...] RIP: 0010:rtm_get_nexthop (net/ipv4/nexthop.c:3395) [...] Call Trace: <TASK> rtnetlink_rcv_msg (net/core/rtnetlink.c:6989) netlink_rcv_skb (net/netlink/af_netlink.c:2550) netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) ____sys_sendmsg (net/socket.c:721 net/socket.c:736 net/socket.c:2585) ___sys_sendmsg (net/socket.c:2641) __sys_sendmsg (net/socket.c:2671) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) </TASK> Fix this by allocating the size dynamically using nh_nlmsg_size() and using nlmsg_new(), this is consistent with nexthop_notify() behavior. In addition, adjust nh_nlmsg_size_grp() so it calculates the size needed based on flags passed. While at it, also add the size of NHA_FDB for nexthop group size calculation as it was missing too. This cannot be reproduced via iproute2 as the group size is currently limited and the command fails as follows: addattr_l ERROR: message exceeded bound of 1048 Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Reported-by: Yiming Qian <yimingqian591@gmail.com> Closes: https://lore.kernel.org/netdev/CAL_bE8Li2h4KO+AQFXW4S6Yb_u5X4oSKnkywW+LPFjuErhqELA@mail.gmail.com/ Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260402072613.25262-2-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03ipv4: nexthop: avoid duplicate NHA_HW_STATS_ENABLE on nexthop group dumpFernando Fernandez Mancera
Currently NHA_HW_STATS_ENABLE is included twice everytime a dump of nexthop group is performed with NHA_OP_FLAG_DUMP_STATS. As all the stats querying were moved to nla_put_nh_group_stats(), leave only that instance of the attribute querying. Fixes: 5072ae00aea4 ("net: nexthop: Expose nexthop group HW stats to user space") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260402072613.25262-1-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03inet: remove leftover EXPORT_SYMBOL()Eric Dumazet
IPv6 is no longer a module, we no longer need to export these symbols. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260402174430.2462800-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-29ipv4: drop ipv6_stub usage and use direct function callsFernando Fernandez Mancera
As IPv6 is built-in only, the ipv6_stub infrastructure is no longer necessary. The IPv4 stack interacts with IPv6 mainly to support IPv4 routes with IPv6 next-hops (RFC 8950). Convert all these cross-family calls from ipv6_stub to direct function calls. The fallback functions introduced previously will prevent linkage errors when CONFIG_IPV6 is disabled. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Tested-by: Ricardo B. Marlière <rbm@suse.com> Link: https://patch.msgid.link/20260325120928.15848-8-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-29net: remove EXPORT_IPV6_MOD() and EXPORT_IPV6_MOD_GPL() macrosFernando Fernandez Mancera
As IPv6 is built-in only, the macro is always evaluating to an empty one. Remove it completely from the code. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260325120928.15848-3-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-29ipv6: convert CONFIG_IPV6 to built-in only and clean up KconfigsFernando Fernandez Mancera
Maintaining a modular IPv6 stack offers image size savings for specific setups, this benefit is outweighed by the architectural burden it imposes on the subsystems on implementation and maintenance. Therefore, drop it. Change CONFIG_IPV6 from tristate to bool. Remove all Kconfig dependencies across the tree that explicitly checked for IPV6=m. In addition, remove MODULE_DESCRIPTION(), MODULE_ALIAS(), MODULE_AUTHOR() and MODULE_LICENSE(). This is also replacing module_init() by device_initcall(). It is not possible to use fs_initcall() as IPv4 does because that creates a race condition on IPv6 addrconf. Finally, modify the default configs from CONFIG_IPV6=m to CONFIG_IPV6=y except for m68k as according to the bloat-o-meter the image is increasing by 330KB~ and that isn't acceptable. Instead, disable IPv6 on this architecture by default. This is aligned with m68k RAM requirements and recommendations [1]. [1] http://www.linux-m68k.org/faq/ram.html Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Tested-by: Ricardo B. Marlière <rbm@suse.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> # arm64 Link: https://patch.msgid.link/20260325120928.15848-2-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-26tcp: tcp_vegas: use tcp_vegas_cwnd_event_tx_start()Eric Dumazet
While net/ipv4/tcp_yeah.c is correctly setting .cwnd_event_tx_start to tcp_vegas_cwnd_event_tx_start(), I forgot to do the same in tcp_vegas.c Fixes: d1e59a469737 ("tcp: add cwnd_event_tx_start to tcp_congestion_ops") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260325212440.4146579-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.0-rc6). No conflicts, or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-24tcp: add cwnd_event_tx_start to tcp_congestion_opsEric Dumazet
(tcp_congestion_ops)->cwnd_event() is called very often, with @event oscillating between CA_EVENT_TX_START and other values. This is not branch prediction friendly. Provide a new cwnd_event_tx_start pointer dedicated for CA_EVENT_TX_START. Both BBR and CUBIC benefit from this change, since they only care about CA_EVENT_TX_START. No change in kernel size: $ scripts/bloat-o-meter -t vmlinux.0 vmlinux add/remove: 4/4 grow/shrink: 3/1 up/down: 564/-568 (-4) Function old new delta bbr_cwnd_event_tx_start - 450 +450 cubictcp_cwnd_event_tx_start - 70 +70 __pfx_cubictcp_cwnd_event_tx_start - 16 +16 __pfx_bbr_cwnd_event_tx_start - 16 +16 tcp_unregister_congestion_control 93 99 +6 tcp_update_congestion_control 518 521 +3 tcp_register_congestion_control 422 425 +3 __tcp_transmit_skb 3308 3306 -2 __pfx_cubictcp_cwnd_event 16 - -16 __pfx_bbr_cwnd_event 16 - -16 cubictcp_cwnd_event 80 - -80 bbr_cwnd_event 454 - -454 Total: Before=25240512, After=25240508, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260323234920.1097858-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-24Merge tag 'ipsec-2026-03-23' of ↵Paolo Abeni
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2026-03-23 1) Add missing extack for XFRMA_SA_PCPU in add_acquire and allocspi. From Sabrina Dubroca. 2) Fix the condition on x->pcpu_num in xfrm_sa_len by using the proper check. From Sabrina Dubroca. 3) Call xdo_dev_state_delete during state update to properly cleanup the xdo device state. From Sabrina Dubroca. 4) Fix a potential skb leak in espintcp when async crypto is used. From Sabrina Dubroca. 5) Validate inner IPv4 header length in IPTFS payload to avoid parsing malformed packets. From Roshan Kumar. 6) Fix skb_put() panic on non-linear skb during IPTFS reassembly. From Fernando Fernandez Mancera. 7) Silence various sparse warnings related to RCU, state, and policy handling. From Sabrina Dubroca. 8) Fix work re-schedule race after cancel in xfrm_nat_keepalive_net_fini(). From Hyunwoo Kim. 9) Prevent policy_hthresh.work from racing with netns teardown by using a proper cleanup mechanism. From Minwoo Ra. 10) Validate that the family of the source and destination addresses match in pfkey_send_migrate(). From Eric Dumazet. 11) Only publish mode_data after the clone is setup in the IPTFS receive path. This prevents leaving x->mode_data pointing at freed memory on error. From Paul Moses. Please pull or let me know if there are problems. ipsec-2026-03-23 * tag 'ipsec-2026-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: iptfs: only publish mode_data after clone setup af_key: validate families in pfkey_send_migrate() xfrm: prevent policy_hthresh.work from racing with netns teardown xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini() xfrm: avoid RCU warnings around the per-netns netlink socket xfrm: add rcu_access_pointer to silence sparse warning for xfrm_input_afinfo xfrm: policy: silence sparse warning in xfrm_policy_unregister_afinfo xfrm: policy: fix sparse warnings in xfrm_policy_{init,fini} xfrm: state: silence sparse warnings during netns exit xfrm: remove rcu/state_hold from xfrm_state_lookup_spi_proto xfrm: state: add xfrm_state_deref_prot to state_by* walk under lock xfrm: state: fix sparse warnings around XFRM_STATE_INSERT xfrm: state: fix sparse warnings in xfrm_state_init xfrm: state: fix sparse warnings on xfrm_state_hold_rcu xfrm: iptfs: fix skb_put() panic on non-linear skb during reassembly xfrm: iptfs: validate inner IPv4 header length in IPTFS payload esp: fix skb leak with espintcp and async crypto xfrm: call xdo_dev_state_delete during state update xfrm: fix the condition on x->pcpu_num in xfrm_sa_len xfrm: add missing extack for XFRMA_SA_PCPU in add_acquire and allocspi ==================== Link: https://patch.msgid.link/20260323083440.2741292-1-steffen.klassert@secunet.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-23udp: Fix wildcard bind conflict check when using hash2Martin KaFai Lau
When binding a udp_sock to a local address and port, UDP uses two hashes (udptable->hash and udptable->hash2) for collision detection. The current code switches to "hash2" when hslot->count > 10. "hash2" is keyed by local address and local port. "hash" is keyed by local port only. The issue can be shown in the following bind sequence (pseudo code): bind(fd1, "[fd00::1]:8888") bind(fd2, "[fd00::2]:8888") bind(fd3, "[fd00::3]:8888") bind(fd4, "[fd00::4]:8888") bind(fd5, "[fd00::5]:8888") bind(fd6, "[fd00::6]:8888") bind(fd7, "[fd00::7]:8888") bind(fd8, "[fd00::8]:8888") bind(fd9, "[fd00::9]:8888") bind(fd10, "[fd00::10]:8888") /* Correctly return -EADDRINUSE because "hash" is used * instead of "hash2". udp_lib_lport_inuse() detects the * conflict. */ bind(fail_fd, "[::]:8888") /* After one more socket is bound to "[fd00::11]:8888", * hslot->count exceeds 10 and "hash2" is used instead. */ bind(fd11, "[fd00::11]:8888") bind(fail_fd, "[::]:8888") /* succeeds unexpectedly */ The same issue applies to the IPv4 wildcard address "0.0.0.0" and the IPv4-mapped wildcard address "::ffff:0.0.0.0". For example, if there are existing sockets bound to "192.168.1.[1-11]:8888", then binding "0.0.0.0:8888" or "[::ffff:0.0.0.0]:8888" can also miss the conflict when hslot->count > 10. TCP inet_csk_get_port() already has the correct check in inet_use_bhash2_on_bind(). Rename it to inet_use_hash2_on_bind() and move it to inet_hashtables.h so udp.c can reuse it in this fix. Fixes: 30fff9231fad ("udp: bind() optimisation") Reported-by: Andrew Onyshchuk <oandrew@meta.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260319181817.1901357-1-martin.lau@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.0-rc5). net/netfilter/nft_set_rbtree.c 598adea720b97 ("netfilter: revert nft_set_rbtree: validate open interval overlap") 3aea466a43998 ("netfilter: nft_set_rbtree: don't disable bh when acquiring tree lock") https://lore.kernel.org/abgaQBpeGstdN4oq@sirena.org.uk No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-19icmp: fix NULL pointer dereference in icmp_tag_validation()Weiming Shi
icmp_tag_validation() unconditionally dereferences the result of rcu_dereference(inet_protos[proto]) without checking for NULL. The inet_protos[] array is sparse -- only about 15 of 256 protocol numbers have registered handlers. When ip_no_pmtu_disc is set to 3 (hardened PMTU mode) and the kernel receives an ICMP Fragmentation Needed error with a quoted inner IP header containing an unregistered protocol number, the NULL dereference causes a kernel panic in softirq context. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:icmp_unreach (net/ipv4/icmp.c:1085 net/ipv4/icmp.c:1143) Call Trace: <IRQ> icmp_rcv (net/ipv4/icmp.c:1527) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:207) ip_local_deliver_finish (net/ipv4/ip_input.c:242) ip_local_deliver (net/ipv4/ip_input.c:262) ip_rcv (net/ipv4/ip_input.c:573) __netif_receive_skb_one_core (net/core/dev.c:6164) process_backlog (net/core/dev.c:6628) handle_softirqs (kernel/softirq.c:561) </IRQ> Add a NULL check before accessing icmp_strict_tag_validation. If the protocol has no registered handler, return false since it cannot perform strict tag validation. Fixes: 8ed1dc44d3e9 ("ipv4: introduce hardened ip_no_pmtu_disc mode") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Link: https://patch.msgid.link/20260318130558.1050247-4-bestswngs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-17fou: Remove IPPROTO_UDPLITE check in gue_err() and gue6_err().Kuniyuki Iwashima
UDP-Lite has been removed, and its error handler is no longer found in either inet_protos[IPPROTO_UDPLITE] or inet6_protos[IPPROTO_UDPLITE]. The recursion fixed by the protocol check in gue_err() and gue6_err() no longer occurs with UDP-Lite. Let's remove the checks. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Joe Damato <joe@dama.to> Link: https://patch.msgid.link/20260316133127.2646421-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-16bonding: prevent potential infinite loop in bond_header_parse()Eric Dumazet
bond_header_parse() can loop if a stack of two bonding devices is setup, because skb->dev always points to the hierarchy top. Add new "const struct net_device *dev" parameter to (struct header_ops)->parse() method to make sure the recursion is bounded, and that the final leaf parse method is called. Fixes: 950803f72547 ("bonding: fix type confusion in bond_setup_by_slave()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@shopee.com> Tested-by: Jiayuan Chen <jiayuan.chen@shopee.com> Cc: Jay Vosburgh <jv@jvosburgh.net> Cc: Andrew Lunn <andrew+netdev@lunn.ch> Link: https://patch.msgid.link/20260315104152.1436867-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-14ipv4: validate IPV4_DEVCONF attributes properlyFernando Fernandez Mancera
As the IPV4_DEVCONF netlink attributes are not being validated, it is possible to use netlink to set read-only values like mc_forwarding. In addition, valid ranges are not being validated neither but that is less relevant as they aren't in sysctl. To avoid similar situations in the future, define a NLA policy for IPV4_DEVCONF attributes which are nested in IFLA_INET_CONF. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260312142637.5704-1-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-14net: dropreason: add SKB_DROP_REASON_RECURSION_LIMITEric Dumazet
ip[6]tunnel_xmit() can drop packets if a too deep recursion level is detected. Add SKB_DROP_REASON_RECURSION_LIMIT drop reason. We will use this reason later in __dev_queue_xmit(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <joe@dama.to> Link: https://patch.msgid.link/20260312201824.203093-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-14tcp: increase LINUX_MIB_BEYOND_WINDOW for SKB_DROP_REASON_TCP_OVERWINDOWSimon Baatz
Since commit 9ca48d616ed7 ("tcp: do not accept packets beyond window"), the path leading to SKB_DROP_REASON_TCP_OVERWINDOW in tcp_data_queue() is probably dead. However, it can be reached now when tcp_max_receive_window() is larger than tcp_receive_window(). In that case, increment LINUX_MIB_BEYOND_WINDOW as done in tcp_sequence(). Signed-off-by: Simon Baatz <gmbnomis@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260309-tcp_rfc7323_retract_wnd_rfc-v3-3-4c7f96b1ec69@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-14tcp: implement RFC 7323 window retraction receiver requirementsSimon Baatz
By default, the Linux TCP implementation does not shrink the advertised window (RFC 7323 calls this "window retraction") with the following exceptions: - When an incoming segment cannot be added due to the receive buffer running out of memory. Since commit 8c670bdfa58e ("tcp: correct handling of extreme memory squeeze") a zero window will be advertised in this case. It turns out that reaching the required memory pressure is easy when window scaling is in use. In the simplest case, sending a sufficient number of segments smaller than the scale factor to a receiver that does not read data is enough. - Commit b650d953cd39 ("tcp: enforce receive buffer memory limits by allowing the tcp window to shrink") addressed the "eating memory" problem by introducing a sysctl knob that allows shrinking the window before running out of memory. However, RFC 7323 does not only state that shrinking the window is necessary in some cases, it also formulates requirements for TCP implementations when doing so (Section 2.4). This commit addresses the receiver-side requirements: After retracting the window, the peer may have a snd_nxt that lies within a previously advertised window but is now beyond the retracted window. This means that all incoming segments (including pure ACKs) will be rejected until the application happens to read enough data to let the peer's snd_nxt be in window again (which may be never). To comply with RFC 7323, the receiver MUST honor any segment that would have been in window for any ACK sent by the receiver and, when window scaling is in effect, SHOULD track the maximum window sequence number it has advertised. This patch tracks that maximum window sequence number rcv_mwnd_seq throughout the connection and uses it in tcp_sequence() when deciding whether a segment is acceptable. rcv_mwnd_seq is updated together with rcv_wup and rcv_wnd in tcp_select_window(). If we count tcp_sequence() as fast path, it is read in the fast path. Therefore, rcv_mwnd_seq is put into rcv_wnd's cacheline group. The logic for handling received data in tcp_data_queue() is already sufficient and does not need to be updated. Signed-off-by: Simon Baatz <gmbnomis@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260309-tcp_rfc7323_retract_wnd_rfc-v3-1-4c7f96b1ec69@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Don't pass proto to __udp4_lib_rcv() and __udp6_lib_rcv().Kuniyuki Iwashima
UDP and UDP-Lite shared __udp4_lib_rcv() and __udp6_lib_rcv() by passing IPPROTO_UDP or IPPROTO_UDPLITE. Now, @proto is always IPPROTO_UDP. Let's not pass it and rename the functions accordingly. With this series removing a bunch of conditionals for UDP-Lite from the fast path, udp_rr with 20,000 flows sees a 10% increase in pps (13.3 Mpps -> 14.7 Mpps) on an AMD EPYC 7B12 (Zen 2) 64-Core Processor platform. [ With FDO, the baseline is much higher and the delta was ~3%, 20.1 Mpps -> 20.7 Mpps ] Before: $ nstat > /dev/null; sleep 1; nstat | grep Udp Udp6InDatagrams 14013408 0.0 Udp6OutDatagrams 14013128 0.0 After: $ nstat > /dev/null; sleep 1; nstat | grep Udp Udp6InDatagrams 15491971 0.0 Udp6OutDatagrams 15491671 0.0 $ ./scripts/bloat-o-meter vmlinux.before vmlinux.after add/remove: 13/75 grow/shrink: 11/75 up/down: 13777/-18401 (-4624) Function old new delta udp4_gro_receive 872 866 -6 udp6_gro_receive 910 903 -7 udp_rcv 32 1727 +1695 udpv6_rcv 32 1450 +1418 __udp4_lib_rcv 2045 - -2045 __udp6_lib_rcv 2084 - -2084 udp_unicast_rcv_skb 160 149 -11 udp6_unicast_rcv_skb 196 181 -15 __udp4_lib_mcast_deliver 925 846 -79 __udp6_lib_mcast_deliver 922 810 -112 __udp4_lib_lookup 973 969 -4 __udp6_lib_lookup 940 929 -11 __udp4_lib_lookup_skb 106 100 -6 __udp6_lib_lookup_skb 71 66 -5 udp4_lib_lookup_skb 132 127 -5 udp6_lib_lookup_skb 87 81 -6 udp_queue_rcv_skb 326 356 +30 udpv6_queue_rcv_skb 331 361 +30 udp_queue_rcv_one_skb 1233 914 -319 udpv6_queue_rcv_one_skb 1250 930 -320 __udp_enqueue_schedule_skb 1067 995 -72 udp_rcv_segment 520 480 -40 udp_post_segment_fix_csum 120 - -120 udp_lib_checksum_complete 200 84 -116 udp_err 27 1103 +1076 udpv6_err 36 1417 +1381 __udp4_lib_err 1112 - -1112 __udp6_lib_err 1448 - -1448 udp_recvmsg 1149 994 -155 udpv6_recvmsg 1349 1294 -55 udp_sendmsg 2730 2648 -82 udp_send_skb 909 681 -228 udpv6_sendmsg 3022 2861 -161 udp_v6_send_skb 1214 952 -262 ... Total: Before=18446744073748075501, After=18446744073748070877, chg -0.00% Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-16-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Don't pass udptable to IPv4 socket lookup functions.Kuniyuki Iwashima
Since UDP and UDP-Lite had dedicated socket hash tables for each, we have had to pass the pointer down to many socket lookup functions. UDP-Lite gone, and we do not need to do that. Let's fetch net->ipv4.udp_table only where needed in IPv4 stack: __udp4_lib_lookup(), __udp4_lib_mcast_deliver(), and udp_diag_dump(). Some functions are renamed as the wrapper functions are no longer needed. __udp4_lib_err() -> udp_err() __udp_diag_destroy() -> udp_diag_destroy() udp_dump_one() -> udp_diag_dump_one() udp_dump() -> udp_diag_dump() Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-15-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Don't pass udptable to IPv6 socket lookup functions.Kuniyuki Iwashima
Since UDP and UDP-Lite had dedicated socket hash tables for each, we have had to pass the pointer down to many socket lookup functions. UDP-Lite gone, and we do not need to do that. Let's fetch net->ipv4.udp_table only where needed in IPv6 stack: __udp6_lib_lookup() and __udp6_lib_mcast_deliver(). __udp6_lib_err() is renamed to udpv6_err() as its wrapper is no longer needed. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-14-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Remove dead check in __udp[46]_lib_lookup() for BPF.Kuniyuki Iwashima
BPF socket lookup for SO_REUSEPORT does not support UDP-Lite. In __udp4_lib_lookup() and __udp6_lib_lookup(), it checks if the passed udptable pointer is the same as net->ipv4.udp_table, which is only true for UDP. Now, the condition is always true. Let's remove the check. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-13-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Remove udp_table in struct udp_seq_afinfo.Kuniyuki Iwashima
Since UDP and UDP-Lite had dedicated socket hash tables for each, we have had to fetch them from different pointers for procfs or bpf iterator. UDP always has its global or per-netns table in net->ipv4.udp_table and struct udp_seq_afinfo.udp_table is NULL. OTOH, UDP-Lite had only one global table in the pointer. We no longer use the field. Let's remove it and udp_get_table_seq(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-12-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Remove struct proto.h.udp_table.Kuniyuki Iwashima
Since UDP and UDP-Lite had dedicated socket hash tables for each, we have had to fetch them from different pointers. UDP always has its global or per-netns table in net->ipv4.udp_table and struct proto.h.udp_table is NULL. OTOH, UDP-Lite had only one global table in the pointer. We no longer use the field. Let's remove it and udp_get_table_prot(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-11-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Remove UDPLITE_SEND_CSCOV and UDPLITE_RECV_CSCOV.Kuniyuki Iwashima
UDP-Lite supports variable-length checksum and has two socket options, UDPLITE_SEND_CSCOV and UDPLITE_RECV_CSCOV, to control the checksum coverage. Let's remove the support. setsockopt(UDPLITE_SEND_CSCOV / UDPLITE_RECV_CSCOV) was only available for UDP-Lite and returned -ENOPROTOOPT for UDP. Now, the options are handled in ip_setsockopt() and ipv6_setsockopt(), which still return the same error. getsockopt(UDPLITE_SEND_CSCOV / UDPLITE_RECV_CSCOV) was available for UDP and always returned 0, meaning full checksum, but now -ENOPROTOOPT is returned. Given that getsockopt() is meaningless for UDP and even the options are not defined under include/uapi/, this should not be a problem. $ man 7 udplite ... BUGS Where glibc support is missing, the following definitions are needed: #define IPPROTO_UDPLITE 136 #define UDPLITE_SEND_CSCOV 10 #define UDPLITE_RECV_CSCOV 11 Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-10-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Remove partial csum code in TX.Kuniyuki Iwashima
UDP TX paths also have some code for UDP-Lite partial checksum: * udplite_csum() in udp_send_skb() and udp_v6_send_skb() * udplite_getfrag() in udp_sendmsg() and udpv6_sendmsg() Let's remove such code. Now, we can use IPPROTO_UDP directly instead of sk->sk_protocol or fl6->flowi6_proto for csum_tcpudp_magic() and csum_ipv6_magic(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-9-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Remove partial csum code in RX.Kuniyuki Iwashima
UDP-Lite supports the partial checksum and the coverage is stored in the position of the length field of struct udphdr. In RX paths, udp4_csum_init() / udp6_csum_init() save the value in UDP_SKB_CB(skb)->cscov and set UDP_SKB_CB(skb)->partial_cov to 1 if the coverage is not full. The subsequent processing diverges depending on the value, but such paths are now dead. Also, these functions have some code guarded for UDP: * udp_unicast_rcv_skb / udp6_unicast_rcv_skb * __udp4_lib_rcv() and __udp6_lib_rcv(). Let's remove the partial csum code and the unnecessary guard for UDP-Lite in RX. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-8-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Remove UDP-Lite SNMP stats.Kuniyuki Iwashima
Since UDP and UDP-Lite shared most of the code, we have had to check the protocol every time we increment SNMP stats. Now that the UDP-Lite paths are dead, let's remove UDP-Lite SNMP stats. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13ipv4: Retire UDP-Lite.Kuniyuki Iwashima
We have deprecated IPv6 UDP-Lite sockets. Let's drop support for IPv4 UDP-Lite sockets as well. Most of the changes are similar to the IPv6 patch: removing udplite.c and udp_impl.h, marking most functions in udp_impl.h as static, moving the prototype for udp_recvmsg() to udp.h, and adding INDIRECT_CALLABLE_SCOPE for it. In addition, the INET_DIAG support for UDP-Lite is dropped. We will remove the remaining dead code in the following patches. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-5-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-13udp: Make udp[46]_seq_show() static.Kuniyuki Iwashima
Since commit a3d2599b2446 ("ipv{4,6}/udp{,lite}: simplify proc registration"), udp4_seq_show() and udp6_seq_show() are not used in net/ipv4/udplite.c and net/ipv6/udplite.c. Instead, udp_seq_ops and udp6_seq_ops are exposed to UDP-Lite. Let's make udp4_seq_show() and udp6_seq_show() static. udp_seq_ops and udp6_seq_ops are moved to udp_impl.h so that we can make them static when the header is removed. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.0-rc4). drivers/net/ethernet/mellanox/mlx5/core/en_rx.c db25c42c2e1f9 ("net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ") dff1c3164a692 ("net/mlx5e: SHAMPO, Always calculate page size") https://lore.kernel.org/aa7ORohmf67EKihj@sirena.org.uk drivers/net/ethernet/ti/am65-cpsw-nuss.c 840c9d13cb1ca ("net: ethernet: ti: am65-cpsw-nuss: Fix rx_filter value for PTP support") a23c657e332f2 ("net: ethernet: ti: am65-cpsw: Use also port number to identify timestamps") https://lore.kernel.org/abK3EkIXuVgMyGI7@sirena.org.uk No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-12net: prevent NULL deref in ip[6]tunnel_xmit()Eric Dumazet
Blamed commit missed that both functions can be called with dev == NULL. Also add unlikely() hints for these conditions that only fuzzers can hit. Fixes: 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit functions") Signed-off-by: Eric Dumazet <edumazet@google.com> CC: Weiming Shi <bestswngs@gmail.com> Link: https://patch.msgid.link/20260312043908.2790803-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-12tcp: add tcp_release_cb_cond() helperEric Dumazet
Majority of tcp_release_cb() calls do nothing at all. Provide tcp_release_cb_cond() helper so that release_sock() can avoid these calls. Also hint the compiler that __release_sock() and wake_up() are rarely called. $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-77 (-77) Function old new delta release_sock 258 181 -77 Total: Before=25235790, After=25235713, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260310124451.2280968-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-11ipv6: move the disable_ipv6_mod knob to core codeJakub Kicinski
From: Jakub Kicinski <kuba@kernel.org> Make sure disable_ipv6_mod itself is not part of the IPv6 module, in case core code wants to refer to it. We will remove support for IPv6=m soon, this change helps make fixes we commit before that less messy. Link: https://patch.msgid.link/20260307-net-nd_tbl_fixes-v4-1-e2677e85628c@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-10inet: add ip_local_port_step_width sysctl to improve port usage distributionFernando Fernandez Mancera
With the current port selection algorithm, ports after a reserved port range or long time used port are used more often than others [1]. This causes an uneven port usage distribution. This combines with cloud environments blocking connections between the application server and the database server if there was a previous connection with the same source port, leading to connectivity problems between applications on cloud environments. The real issue here is that these firewalls cannot cope with standards-compliant port reuse. This is a workaround for such situations and an improvement on the distribution of ports selected. The proposed solution is to implement a variant of RFC 6056 Algorithm 5. The step size is selected randomly on every connect() call ensuring it is a coprime with respect to the size of the range of ports we want to scan. This way, we can ensure that all ports within the range are scanned before returning an error. To enable this algorithm, the user must configure the new sysctl option "net.ipv4.ip_local_port_step_width". In addition, on graphs generated we can observe that the distribution of source ports is more even with the proposed approach. [2] [1] https://0xffsoftware.com/port_graph_current_alg.html [2] https://0xffsoftware.com/port_graph_random_step_alg.html Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260309023946.5473-2-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-10net: add xmit recursion limit to tunnel xmit functionsWeiming Shi
Tunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own recursion limit. When a bond device in broadcast mode has GRE tap interfaces as slaves, and those GRE tunnels route back through the bond, multicast/broadcast traffic triggers infinite recursion between bond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing kernel stack overflow. The existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not sufficient because tunnel recursion involves route lookups and full IP output, consuming much more stack per level. Use a lower limit of 4 (IP_TUNNEL_RECURSION_LIMIT) to prevent overflow. Add recursion detection using dev_xmit_recursion helpers directly in iptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel paths including UDP encapsulated tunnels (VXLAN, Geneve, etc.). Move dev_xmit_recursion helpers from net/core/dev.h to public header include/linux/netdevice.h so they can be used by tunnel code. BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160 Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11 Workqueue: mld mld_ifc_work Call Trace: <TASK> __build_flow_key.constprop.0 (net/ipv4/route.c:515) ip_rt_update_pmtu (net/ipv4/route.c:1073) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84) ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) ip_finish_output2 (net/ipv4/ip_output.c:237) ip_output (net/ipv4/ip_output.c:438) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) ip_finish_output2 (net/ipv4/ip_output.c:237) ip_output (net/ipv4/ip_output.c:438) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86) ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) mld_sendpack mld_ifc_work process_one_work worker_thread </TASK> Fixes: 745e20f1b626 ("net: add a recursion limit in xmit path") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Link: https://patch.msgid.link/20260306160133.3852900-2-bestswngs@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-09tcp: inline tcp_chrono_start()Eric Dumazet
tcp_chrono_start() is small enough, and used in TCP sendmsg() fast path (from tcp_skb_entail()). Note clang is already inlining it from functions in tcp_output.c. Inlining it improves performance and reduces bloat : $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 0/2 grow/shrink: 1/0 up/down: 1/-84 (-83) Function old new delta tcp_skb_entail 280 281 +1 __pfx_tcp_chrono_start 16 - -16 tcp_chrono_start 68 - -68 Total: Before=25192434, After=25192351, chg -0.00% Note that tcp_chrono_stop() is too big. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20260308123549.2924460-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09tcp: avoid dst->ops->check() call in tcp_v{4,6}_do_rcv()Eric Dumazet
If incoming skb dst matches the socket cached one, there is no need to call again dst->ops->check(). Network layer already validated the skb dst for us, usually from tcp_v{4,6}_early_demux(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260306154322.1086539-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09tcp: move tcp_v4_early_demux() to net/ipv4/ip_input.cEric Dumazet
tcp_v4_early_demux() has a single caller : ip_rcv_finish_core(). Move it to net/ipv4/ip_input.c and mark it static, for possible compiler/linker optimizations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260306131130.654991-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09tcp: remove unused hash_size from struct tcp_out_optionsKeita Morisaki
hash_size is declared but never read. The MD5 path always uses a fixed size of 16, and the TCP-AO path uses tcp_ao_maclen(). This closes a 7-byte hole and reduces the struct size from 96 to 88 bytes. Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Keita Morisaki <kmta1236@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260307051619.51685-1-kmta1236@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09net: nexthop: fix percpu use-after-free in remove_nh_grp_entryMehul Rao
When removing a nexthop from a group, remove_nh_grp_entry() publishes the new group via rcu_assign_pointer() then immediately frees the removed entry's percpu stats with free_percpu(). However, the synchronize_net() grace period in the caller remove_nexthop_from_groups() runs after the free. RCU readers that entered before the publish still see the old group and can dereference the freed stats via nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a use-after-free on percpu memory. Fix by deferring the free_percpu() until after synchronize_net() in the caller. Removed entries are chained via nh_list onto a local deferred free list. After the grace period completes and all RCU readers have finished, the percpu stats are safely freed. Fixes: f4676ea74b85 ("net: nexthop: Add nexthop group entry stats") Cc: stable@vger.kernel.org Signed-off-by: Mehul Rao <mehulrao@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260306233821.196789-1-mehulrao@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09net: Add SPDX ids to some source filesTim Bird
Add SPDX-License-Identifier lines to several source files under the network sub-directory. Work on files in the core, dns_resolver, ipv4, ipv6 and netfilter sub-dirs. Remove boilerplate and license reference text to avoid ambiguity. Rusty Russell has expressed that his contributions were intended to be GPL-2.0-or-later. Signed-off-by: Tim Bird <tim.bird@sony.com> Link: https://patch.msgid.link/20260305004724.87469-1-tim.bird@sony.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-06net: annotate data races around sk->sk_protJiayuan Chen
inet_sendmsg() and inet_recvmsg() access sk->sk_prot without lock_sock() or any other synchronization. sock_replace_proto() (used by sockmap), TLS and MPTCP can change sk->sk_prot under us, so these functions need READ_ONCE() to avoid load tearing. Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260304064253.16955-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-06inet_diag: report delayed ack timer informationEric Dumazet
inet_sk_diag_fill() populates r->idiag_timer with the following precedence order: 1 - Retransmit timer. 4 - Probe0 timer. 2 - Keepalive timer. This patch adds a new value, last in the list, if other timers are not active. 5 - Delayed ACK timer. A corresponding iproute2 patch will follow to replace "unknown" with "delack": ESTAB 10 0 [2002:a05:6830:1f86::]:12875 [2002:a05:6830:1f85::]:50438 timer:(unknown,003ms,0) ino:152178 sk:3004 cgroup:unreachable:189 <-> skmem:(r1344,rb12780520,t0,tb262144,f2752,w0,o250,bl0,d0) ts usec_ts ... Also add the following enum in uapi/linux/inet_diag.h as suggested by David Ahern. enum { IDIAG_TIMER_OFF, IDIAG_TIMER_ON, IDIAG_TIMER_KEEPALIVE, IDIAG_TIMER_TIMEWAIT, IDIAG_TIMER_PROBE0, IDIAG_TIMER_DELACK, }; Neal Cardwell suggested to test for ICSK_ACK_TIMER: inet_csk_clear_xmit_timer() does not call sk_stop_timer() because INET_CSK_CLEAR_TIMERS is unset. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260305114829.2163276-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-06net: change sock.sk_ino and sock_i_ino() to u64Jeff Layton
inode->i_ino is being converted to a u64. sock.sk_ino (which caches the inode number) must also be widened to avoid truncation on 32-bit architectures where unsigned long is only 32 bits. Change sk_ino from unsigned long to u64, and update the return type of sock_i_ino() to match. Fix all format strings that print the result of sock_i_ino() (%lu -> %llu), and widen the intermediate variables and function parameters in the diag modules that were using int to hold the inode number. Note that the UAPI socket diag structures (inet_diag_msg.idiag_inode, unix_diag_msg.udiag_ino, etc.) are all __u32 and cannot be changed without breaking the ABI. The assignments to those fields will silently truncate, which is the existing behavior. Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260304-iino-u64-v3-3-2257ad83d372@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-05tcp: Initialise ehash secrets during connect() and listen().Kuniyuki Iwashima
inet_ehashfn() and inet6_ehashfn() initialise random secrets on the first call by net_get_random_once(). While the init part is patched out using static keys, with CONFIG_STACKPROTECTOR_STRONG=y, this causes a compiler to generate a stack canary due to an automatic variable, unsigned long ___flags, in the DO_ONCE() macro being passed to __do_once_start(). With FDO, this is visible in __inet_lookup_established() and __inet6_lookup_established() too. Let's initialise the secrets by get_random_sleepable_once() in the slow paths: inet_hash() for listen(), and inet_hash_connect() and inet6_hash_connect() for connect(). Note that IPv6 listener will initialise both IPv4 & IPv6 secrets in inet_hash() for IPv4-mapped IPv6 address. With the patch, the stack size is reduced by 16 bytes (___flags + a stack canary) and NOPs for the static key go away. Before: __inet6_lookup_established() ... push %rbx sub $0x38,%rsp # stack is 56 bytes mov %edx,%ebx # sport mov %gs:0x299419f(%rip),%rax # load stack canary mov %rax,0x30(%rsp) and store it onto stack mov 0x440(%rdi),%r15 # net->ipv4.tcp_death_row.hashinfo nop 32: mov %r8d,%ebp # hnum shl $0x10,%ebp # hnum << 16 nop 3d: mov 0x70(%rsp),%r14d # sdif or %ebx,%ebp # INET_COMBINED_PORTS(sport, hnum) mov 0x11a8382(%rip),%eax # inet6_ehashfn() ... After: __inet6_lookup_established() ... push %rbx sub $0x28,%rsp # stack is 40 bytes mov 0x60(%rsp),%ebp # sdif mov %r8d,%r14d # hnum shl $0x10,%r14d # hnum << 16 or %edx,%r14d # INET_COMBINED_PORTS(sport, hnum) mov 0x440(%rdi),%rax # net->ipv4.tcp_death_row.hashinfo mov 0x1194f09(%rip),%r10d # inet6_ehashfn() ... Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260303235424.3877267-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-05tcp: shrink per-packet memset in __tcp_transmit_skb()Keita Morisaki
Use struct_group() to group the three fields in tcp_out_options that are read unconditionally by tcp_options_write() and bpf_skops_write_hdr_opt() (mss, bpf_opt_len, num_sack_blocks), then replace the full-struct memset with a targeted memset of only that group. struct tcp_out_options is 40 bytes without MPTCP and 96 bytes with CONFIG_MPTCP=y (typical distro config). Every remaining field is either assigned before first use by tcp_established_options()/tcp_syn_options(), or gated behind its OPTION_* flag in tcp_options_write(). This memset runs on every transmitted TCP packet, so shrinking it from 96 (or 40) bytes to 4 bytes reduces per-packet overhead on the hot path. Assembly comparison (x86-64, GCC 13, CONFIG_MPTCP=y): Before: rep stos zeroing 96 bytes (5 instructions, 12 8-byte stores) After: movl $0x0 zeroing 4 bytes (1 instruction, 1 store) Also add opts->options = 0 at the top of tcp_syn_options(), which already used |= without a prior clear. tcp_established_options() already clears opts->options at its top. Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Keita Morisaki <kmta1236@gmail.com> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260304111517.2088694-1-kmta1236@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>