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2025-10-23tcp: Remove unnecessary null check in tcp_inbound_md5_hash()Eric Biggers
The 'if (!key && hash_location)' check in tcp_inbound_md5_hash() implies that hash_location might be null. However, later code in the function dereferences hash_location anyway, without checking for null first. Fortunately, there is no real bug, since tcp_inbound_md5_hash() is called only with non-null values of hash_location. Therefore, remove the unnecessary and misleading null check of hash_location. This silences a Smatch static checker warning (https://lore.kernel.org/netdev/aPi4b6aWBbBR52P1@stanley.mountain/) Also fix the related comment at the beginning of the function. Signed-off-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://patch.msgid.link/20251022221209.19716-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Martin KaFai Lau says: ==================== pull-request: bpf-next 2025-10-16 We've added 6 non-merge commits during the last 1 day(s) which contain a total of 18 files changed, 577 insertions(+), 38 deletions(-). The main changes are: 1) Bypass the global per-protocol memory accounting either by setting a netns sysctl or using bpf_setsockopt in a bpf program, from Kuniyuki Iwashima. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: selftests/bpf: Add test for sk->sk_bypass_prot_mem. bpf: Introduce SK_BPF_BYPASS_PROT_MEM. bpf: Support bpf_setsockopt() for BPF_CGROUP_INET_SOCK_CREATE. net: Introduce net.core.bypass_prot_mem sysctl. net: Allow opt-out from global protocol memory accounting. tcp: Save lock_sock() for memcg in inet_csk_accept(). ==================== Link: https://patch.msgid.link/20251016204539.773707-1-martin.lau@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17tcp: Convert tcp-md5 to use MD5 library instead of crypto_ahashEric Biggers
Make tcp-md5 use the MD5 library API (added in 6.18) instead of the crypto_ahash API. This is much simpler and also more efficient: - The library API just operates on struct md5_ctx. Just allocate this struct on the stack instead of using a pool of pre-allocated crypto_ahash and ahash_request objects. - The library API accepts standard pointers and doesn't require scatterlists. So, for hashing the headers just use an on-stack buffer instead of a pool of pre-allocated kmalloc'ed scratch buffers. - The library API never fails. Therefore, checking for MD5 hashing errors is no longer necessary. Update tcp_v4_md5_hash_skb(), tcp_v6_md5_hash_skb(), tcp_v4_md5_hash_hdr(), tcp_v6_md5_hash_hdr(), tcp_md5_hash_key(), tcp_sock_af_ops::calc_md5_hash, and tcp_request_sock_ops::calc_md5_hash to return void instead of int. - The library API provides direct access to the MD5 code, eliminating unnecessary overhead such as indirect function calls and scatterlist management. Microbenchmarks of tcp_v4_md5_hash_skb() on x86_64 show a speedup from 7518 to 7041 cycles (6% fewer) with skb->len == 1440, or from 1020 to 678 cycles (33% fewer) with skb->len == 140. Since tcp_sigpool_hash_skb_data() can no longer be used, add a function tcp_md5_hash_skb_data() which is specialized to MD5. Of course, to the extent that this duplicates any code, it's well worth it. To preserve the existing behavior of TCP-MD5 support being disabled when the kernel is booted with "fips=1", make tcp_md5_do_add() check fips_enabled itself. Previously it relied on the error from crypto_alloc_ahash("md5") being bubbled up. I don't know for sure that this is actually needed, but this preserves the existing behavior. Tested with bidirectional TCP-MD5, both IPv4 and IPv6, between a kernel that includes this commit and a kernel that doesn't include this commit. (Side note: please don't use TCP-MD5! It's cryptographically weak. But as long as Linux supports it, it might as well be implemented properly.) Signed-off-by: Eric Biggers <ebiggers@kernel.org> Link: https://patch.msgid.link/20251014215836.115616-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17inet: Avoid ehash lookup race in inet_twsk_hashdance_schedule()Xuanqiang Luo
Since ehash lookups are lockless, if another CPU is converting sk to tw concurrently, fetching the newly inserted tw with tw->tw_refcnt == 0 cause lookup failure. The call trace map is drawn as follows: CPU 0 CPU 1 ----- ----- inet_twsk_hashdance_schedule() spin_lock() inet_twsk_add_node_rcu(tw, ...) __inet_lookup_established() (find tw, failure due to tw_refcnt = 0) __sk_nulls_del_node_init_rcu(sk) refcount_set(&tw->tw_refcnt, 3) spin_unlock() By replacing sk with tw atomically via hlist_nulls_replace_init_rcu() after setting tw_refcnt, we ensure that tw is either fully initialized or not visible to other CPUs, eliminating the race. It's worth noting that we held lock_sock() before the replacement, so there's no need to check if sk is hashed. Thanks to Kuniyuki Iwashima! Fixes: 3ab5aee7fe84 ("net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls") Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251015020236.431822-4-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17inet: Avoid ehash lookup race in inet_ehash_insert()Xuanqiang Luo
Since ehash lookups are lockless, if one CPU performs a lookup while another concurrently deletes and inserts (removing reqsk and inserting sk), the lookup may fail to find the socket, an RST may be sent. The call trace map is drawn as follows: CPU 0 CPU 1 ----- ----- inet_ehash_insert() spin_lock() sk_nulls_del_node_init_rcu(osk) __inet_lookup_established() (lookup failed) __sk_nulls_add_node_rcu(sk, list) spin_unlock() As both deletion and insertion operate on the same ehash chain, this patch introduces a new sk_nulls_replace_node_init_rcu() helper functions to implement atomic replacement. Fixes: 5e0724d027f0 ("tcp/dccp: fix hashdance race for passive sessions") Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251015020236.431822-3-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-16net: Allow opt-out from global protocol memory accounting.Kuniyuki Iwashima
Some protocols (e.g., TCP, UDP) implement memory accounting for socket buffers and charge memory to per-protocol global counters pointed to by sk->sk_proto->memory_allocated. Sometimes, system processes do not want that limitation. For a similar purpose, there is SO_RESERVE_MEM for sockets under memcg. Also, by opting out of the per-protocol accounting, sockets under memcg can avoid paying costs for two orthogonal memory accounting mechanisms. A microbenchmark result is in the subsequent bpf patch. Let's allow opt-out from the per-protocol memory accounting if sk->sk_bypass_prot_mem is true. sk->sk_bypass_prot_mem and sk->sk_prot are placed in the same cache line, and sk_has_account() always fetches sk->sk_prot before accessing sk->sk_bypass_prot_mem, so there is no extra cache miss for this patch. The following patches will set sk->sk_bypass_prot_mem to true, and then, the per-protocol memory accounting will be skipped. Note that this does NOT disable memcg, but rather the per-protocol one. Another option not to use the hole in struct sock_common is create sk_prot variants like tcp_prot_bypass, but this would complicate SOCKMAP logic, tcp_bpf_prots etc. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://patch.msgid.link/20251014235604.3057003-3-kuniyu@google.com
2025-10-16tcp: Save lock_sock() for memcg in inet_csk_accept().Kuniyuki Iwashima
If memcg is enabled, accept() acquires lock_sock() twice for each new TCP/MPTCP socket in inet_csk_accept() and __inet_accept(). Let's move memcg operations from inet_csk_accept() to __inet_accept(). Note that SCTP somehow allocates a new socket by sk_alloc() in sk->sk_prot->accept() and clones fields manually, instead of using sk_clone_lock(). mem_cgroup_sk_alloc() is called for SCTP before __inet_accept(), so I added the protocol check in __inet_accept(), but this can be removed once SCTP uses sk_clone_lock(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://patch.msgid.link/20251014235604.3057003-2-kuniyu@google.com
2025-10-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.18-rc2). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-16udp: do not use skb_release_head_state() before skb_attempt_defer_free()Eric Dumazet
Michal reported and bisected an issue after recent adoption of skb_attempt_defer_free() in UDP. The issue here is that skb_release_head_state() is called twice per skb, one time from skb_consume_udp(), then a second time from skb_defer_free_flush() and napi_consume_skb(). As Sabrina suggested, remove skb_release_head_state() call from skb_consume_udp(). Add a DEBUG_NET_WARN_ON_ONCE(skb_nfct(skb)) in skb_attempt_defer_free() Many thanks to Michal, Sabrina, Paolo and Florian for their help. Fixes: 6471658dc66c ("udp: use skb_attempt_defer_free()") Reported-and-bisected-by: Michal Kubecek <mkubecek@suse.cz> Closes: https://lore.kernel.org/netdev/gpjh4lrotyephiqpuldtxxizrsg6job7cvhiqrw72saz2ubs3h@g6fgbvexgl3r/ Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Michal Kubecek <mkubecek@suse.cz> Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: Florian Westphal <fw@strlen.de> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20251015052715.4140493-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-15tcp: better handle TCP_TX_DELAY on established flowsEric Dumazet
Some applications uses TCP_TX_DELAY socket option after TCP flow is established. Some metrics need to be updated, otherwise TCP might take time to adapt to the new (emulated) RTT. This patch adjusts tp->srtt_us, tp->rtt_min, icsk_rto and sk->sk_pacing_rate. This is best effort, and for instance icsk_rto is reset without taking backoff into account. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251013145926.833198-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-14tcp: fix tcp_tso_should_defer() vs large RTTEric Dumazet
Neal reported that using neper tcp_stream with TCP_TX_DELAY set to 50ms would often lead to flows stuck in a small cwnd mode, regardless of the congestion control. While tcp_stream sets TCP_TX_DELAY too late after the connect(), it highlighted two kernel bugs. The following heuristic in tcp_tso_should_defer() seems wrong for large RTT: delta = tp->tcp_clock_cache - head->tstamp; /* If next ACK is likely to come too late (half srtt), do not defer */ if ((s64)(delta - (u64)NSEC_PER_USEC * (tp->srtt_us >> 4)) < 0) goto send_now; If next ACK is expected to come in more than 1 ms, we should not defer because we prefer a smooth ACK clocking. While blamed commit was a step in the good direction, it was not generic enough. Another patch fixing TCP_TX_DELAY for established flows will be proposed when net-next reopens. Fixes: 50c8339e9299 ("tcp: tso: restore IW10 after TSO autosizing") Reported-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Tested-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251011115742.1245771-1-edumazet@google.com [pabeni@redhat.com: fixed whitespace issue] Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13net/ip6_tunnel: Prevent perpetual tunnel growthDmitry Safonov
Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer. Fixes: 8eb30be0352d ("ipv6: Create ip6_tnl_xmit") Cc: Florian Westphal <fw@strlen.de> Cc: Francesco Ruggeri <fruggeri05@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://patch.msgid.link/20251009-ip6_tunnel-headroom-v2-1-8e4dbd8f7e35@arista.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-06tcp: take care of zero tp->window_clamp in tcp_set_rcvlowat()Eric Dumazet
Some applications (like selftests/net/tcp_mmap.c) call SO_RCVLOWAT on their listener, before accept(). This has an unfortunate effect on wscale selection in tcp_select_initial_window() during 3WHS. For instance, tcp_mmap was negotiating wscale 4, regardless of tcp_rmem[2] and sysctl_rmem_max. Do not change tp->window_clamp if it is zero or bigger than our computed value. Zero value is special, it allows tcp_select_initial_window() to enable autotuning. Note that SO_RCVLOWAT use on listener is probably not wise, because tp->scaling_ratio has a default value, possibly wrong. Fixes: d1361840f8c5 ("tcp: fix SO_RCVLOWAT and RCVBUF autotuning") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251003184119.2526655-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-06tcp: Don't call reqsk_fastopen_remove() in tcp_conn_request().Kuniyuki Iwashima
syzbot reported the splat below in tcp_conn_request(). [0] If a listener is close()d while a TFO socket is being processed in tcp_conn_request(), inet_csk_reqsk_queue_add() does not set reqsk->sk and calls inet_child_forget(), which calls tcp_disconnect() for the TFO socket. After the cited commit, tcp_disconnect() calls reqsk_fastopen_remove(), where reqsk_put() is called due to !reqsk->sk. Then, reqsk_fastopen_remove() in tcp_conn_request() decrements the last req->rsk_refcnt and frees reqsk, and __reqsk_free() at the drop_and_free label causes the refcount underflow for the listener and double-free of the reqsk. Let's remove reqsk_fastopen_remove() in tcp_conn_request(). Note that other callers make sure tp->fastopen_rsk is not NULL. [0]: refcount_t: underflow; use-after-free. WARNING: CPU: 12 PID: 5563 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28) Modules linked in: CPU: 12 UID: 0 PID: 5563 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:refcount_warn_saturate (lib/refcount.c:28) Code: ab e8 8e b4 98 ff 0f 0b c3 cc cc cc cc cc 80 3d a4 e4 d6 01 00 75 9c c6 05 9b e4 d6 01 01 48 c7 c7 e8 df fb ab e8 6a b4 98 ff <0f> 0b e9 03 5b 76 00 cc 80 3d 7d e4 d6 01 00 0f 85 74 ff ff ff c6 RSP: 0018:ffffa79fc0304a98 EFLAGS: 00010246 RAX: d83af4db1c6b3900 RBX: ffff9f65c7a69020 RCX: d83af4db1c6b3900 RDX: 0000000000000000 RSI: 00000000ffff7fff RDI: ffffffffac78a280 RBP: 000000009d781b60 R08: 0000000000007fff R09: ffffffffac6ca280 R10: 0000000000017ffd R11: 0000000000000004 R12: ffff9f65c7b4f100 R13: ffff9f65c7d23c00 R14: ffff9f65c7d26000 R15: ffff9f65c7a64ef8 FS: 00007f9f962176c0(0000) GS:ffff9f65fcf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000180 CR3: 000000000dbbe006 CR4: 0000000000372ef0 Call Trace: <IRQ> tcp_conn_request (./include/linux/refcount.h:400 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/sock.h:1965 ./include/net/request_sock.h:131 net/ipv4/tcp_input.c:7301) tcp_rcv_state_process (net/ipv4/tcp_input.c:6708) tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1670) tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1906) ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:438) ip6_input (net/ipv6/ip6_input.c:500) ipv6_rcv (net/ipv6/ip6_input.c:311) __netif_receive_skb (net/core/dev.c:6104) process_backlog (net/core/dev.c:6456) __napi_poll (net/core/dev.c:7506) net_rx_action (net/core/dev.c:7569 net/core/dev.c:7696) handle_softirqs (kernel/softirq.c:579) do_softirq (kernel/softirq.c:480) </IRQ> Fixes: 45c8a6cc2bcd ("tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251001233755.1340927-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-03net: psp: don't assume reply skbs will have a socketJakub Kicinski
Rx path may be passing around unreferenced sockets, which means that skb_set_owner_edemux() may not set skb->sk and PSP will crash: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:psp_reply_set_decrypted (./include/net/psp/functions.h:132 net/psp/psp_sock.c:287) tcp_v6_send_response.constprop.0 (net/ipv6/tcp_ipv6.c:979) tcp_v6_send_reset (net/ipv6/tcp_ipv6.c:1140 (discriminator 1)) tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1683) tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1912) Fixes: 659a2899a57d ("tcp: add datapath logic for PSP with inline key exchange") Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251001022426.2592750-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-02Merge tag 'net-next-6.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "Core & protocols: - Improve drop account scalability on NUMA hosts for RAW and UDP sockets and the backlog, almost doubling the Pps capacity under DoS - Optimize the UDP RX performance under stress, reducing contention, revisiting the binary layout of the involved data structs and implementing NUMA-aware locking. This improves UDP RX performance by an additional 50%, even more under extreme conditions - Add support for PSP encryption of TCP connections; this mechanism has some similarities with IPsec and TLS, but offers superior HW offloads capabilities - Ongoing work to support Accurate ECN for TCP. AccECN allows more than one congestion notification signal per RTT and is a building block for Low Latency, Low Loss, and Scalable Throughput (L4S) - Reorganize the TCP socket binary layout for data locality, reducing the number of touched cachelines in the fastpath - Refactor skb deferral free to better scale on large multi-NUMA hosts, this improves TCP and UDP RX performances significantly on such HW - Increase the default socket memory buffer limits from 256K to 4M to better fit modern link speeds - Improve handling of setups with a large number of nexthop, making dump operating scaling linearly and avoiding unneeded synchronize_rcu() on delete - Improve bridge handling of VLAN FDB, storing a single entry per bridge instead of one entry per port; this makes the dump order of magnitude faster on large switches - Restore IP ID correctly for encapsulated packets at GSO segmentation time, allowing GRO to merge packets in more scenarios - Improve netfilter matching performance on large sets - Improve MPTCP receive path performance by leveraging recently introduced core infrastructure (skb deferral free) and adopting recent TCP autotuning changes - Allow bridges to redirect to a backup port when the bridge port is administratively down - Introduce MPTCP 'laminar' endpoint that con be used only once per connection and simplify common MPTCP setups - Add RCU safety to dst->dev, closing a lot of possible races - A significant crypto library API for SCTP, MPTCP and IPv6 SR, reducing code duplication - Supports pulling data from an skb frag into the linear area of an XDP buffer Things we sprinkled into general kernel code: - Generate netlink documentation from YAML using an integrated YAML parser Driver API: - Support using IPv6 Flow Label in Rx hash computation and RSS queue selection - Introduce API for fetching the DMA device for a given queue, allowing TCP zerocopy RX on more H/W setups - Make XDP helpers compatible with unreadable memory, allowing more easily building DevMem-enabled drivers with a unified XDP/skbs datapath - Add a new dedicated ethtool callback enabling drivers to provide the number of RX rings directly, improving efficiency and clarity in RX ring queries and RSS configuration - Introduce a burst period for the health reporter, allowing better handling of multiple errors due to the same root cause - Support for DPLL phase offset exponential moving average, controlling the average smoothing factor Device drivers: - Add a new Huawei driver for 3rd gen NIC (hinic3) - Add a new SpacemiT driver for K1 ethernet MAC - Add a generic abstraction for shared memory communication devices (dibps) - Ethernet high-speed NICs: - nVidia/Mellanox: - Use multiple per-queue doorbell, to avoid MMIO contention issues - support adjacent functions, allowing them to delegate their SR-IOV VFs to sibling PFs - support RSS for IPSec offload - support exposing raw cycle counters in PTP and mlx5 - support for disabling host PFs. - Intel (100G, ice, idpf): - ice: support for SRIOV VFs over an Active-Active link aggregate - ice: support for firmware logging via debugfs - ice: support for Earliest TxTime First (ETF) hardware offload - idpf: support basic XDP functionalities and XSk - Broadcom (bnxt): - support Hyper-V VF ID - dynamic SRIOV resource allocations for RoCE - Meta (fbnic): - support queue API, zero-copy Rx and Tx - support basic XDP functionalities - devlink health support for FW crashes and OTP mem corruptions - expand hardware stats coverage to FEC, PHY, and Pause - Wangxun: - support ethtool coalesce options - support for multiple RSS contexts - Ethernet virtual: - Macsec: - replace custom netlink attribute checks with policy-level checks - Bonding: - support aggregator selection based on port priority - Microsoft vNIC: - use page pool fragments for RX buffers instead of full pages to improve memory efficiency - Ethernet NICs consumer, and embedded: - Qualcomm: support Ethernet function for IPQ9574 SoC - Airoha: implement wlan offloading via NPU - Freescale - enetc: add NETC timer PTP driver and add PTP support - fec: enable the Jumbo frame support for i.MX8QM - Renesas (R-Car S4): - support HW offloading for layer 2 switching - support for RZ/{T2H, N2H} SoCs - Cadence (macb): support TAPRIO traffic scheduling - TI: - support for Gigabit ICSS ethernet SoC (icssm-prueth) - Synopsys (stmmac): a lot of cleanups - Ethernet PHYs: - Support 10g-qxgmi phy-mode for AQR412C, Felix DSA and Lynx PCS driver - Support bcm63268 GPHY power control - Support for Micrel lan8842 PHY and PTP - Support for Aquantia AQR412 and AQR115 - CAN: - a large CAN-XL preparation work - reorganize raw_sock and uniqframe struct to minimize memory usage - rcar_canfd: update the CAN-FD handling - WiFi: - extended Neighbor Awareness Networking (NAN) support - S1G channel representation cleanup - improve S1G support - WiFi drivers: - Intel (iwlwifi): - major refactor and cleanup - Broadcom (brcm80211): - support for AP isolation - RealTek (rtw88/89) rtw88/89: - preparation work for RTL8922DE support - MediaTek (mt76): - HW restart improvements - MLO support - Qualcomm/Atheros (ath10k): - GTK rekey fixes - Bluetooth drivers: - btusb: support for several new IDs for MT7925 - btintel: support for BlazarIW core - btintel_pcie: support for _suspend() / _resume() - btintel_pcie: support for Scorpious, Panther Lake-H484 IDs" * tag 'net-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1536 commits) net: stmmac: Add support for Allwinner A523 GMAC200 dt-bindings: net: sun8i-emac: Add A523 GMAC200 compatible Revert "Documentation: net: add flow control guide and document ethtool API" octeontx2-pf: fix bitmap leak octeontx2-vf: fix bitmap leak net/mlx5e: Use extack in set rxfh callback net/mlx5e: Introduce mlx5e_rss_params for RSS configuration net/mlx5e: Introduce mlx5e_rss_init_params net/mlx5e: Remove unused mdev param from RSS indir init net/mlx5: Improve QoS error messages with actual depth values net/mlx5e: Prevent entering switchdev mode with inconsistent netns net/mlx5: HWS, Generalize complex matchers net/mlx5: Improve write-combining test reliability for ARM64 Grace CPUs selftests/net: add tcp_port_share to .gitignore Revert "net/mlx5e: Update and set Xon/Xoff upon MTU set" net: add NUMA awareness to skb_attempt_defer_free() net: use llist for sd->defer_list net: make softnet_data.defer_count an atomic selftests: drv-net: psp: add tests for destroying devices selftests: drv-net: psp: add test for auto-adjusting TCP MSS ...
2025-09-29tcp: make tcp_rcvbuf_grow() accessible to mptcp codePaolo Abeni
To leverage the auto-tuning improvements brought by commit 2da35e4b4df9 ("Merge branch 'tcp-receive-side-improvements'"), the MPTCP stack need to access the mentioned helper. Acked-by: Geliang Tang <geliang@kernel.org> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-2-5da266aa9c1a@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29tcp: use skb->len instead of skb->truesize in tcp_can_ingest()Eric Dumazet
Some applications are stuck to the 20th century and still use small SO_RCVBUF values. After the blamed commit, we can drop packets especially when using LRO/hw-gro enabled NIC and small MSS (1500) values. LRO/hw-gro NIC pack multiple segments into pages, allowing tp->scaling_ratio to be set to a high value. Whenever the receive queue gets full, we can receive a small packet filling RWIN, but with a high skb->truesize, because most NIC use 4K page plus sk_buff metadata even when receiving less than 1500 bytes of payload. Even if we refine how tp->scaling_ratio is estimated, we could have an issue at the start of the flow, because the first round of packets (IW10) will be sent based on the initial tp->scaling_ratio (1/2) Relax tcp_can_ingest() to use skb->len instead of skb->truesize, allowing the peer to use final RWIN, assuming a 'perfect' scaling_ratio of 1. Fixes: 1d2fbaad7cd8 ("tcp: stronger sk_rcvbuf checks") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250927092827.2707901-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29Merge tag 'namespace-6.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull namespace updates from Christian Brauner: "This contains a larger set of changes around the generic namespace infrastructure of the kernel. Each specific namespace type (net, cgroup, mnt, ...) embedds a struct ns_common which carries the reference count of the namespace and so on. We open-coded and cargo-culted so many quirks for each namespace type that it just wasn't scalable anymore. So given there's a bunch of new changes coming in that area I've started cleaning all of this up. The core change is to make it possible to correctly initialize every namespace uniformly and derive the correct initialization settings from the type of the namespace such as namespace operations, namespace type and so on. This leaves the new ns_common_init() function with a single parameter which is the specific namespace type which derives the correct parameters statically. This also means the compiler will yell as soon as someone does something remotely fishy. The ns_common_init() addition also allows us to remove ns_alloc_inum() and drops any special-casing of the initial network namespace in the network namespace initialization code that Linus complained about. Another part is reworking the reference counting. The reference counting was open-coded and copy-pasted for each namespace type even though they all followed the same rules. This also removes all open accesses to the reference count and makes it private and only uses a very small set of dedicated helpers to manipulate them just like we do for e.g., files. In addition this generalizes the mount namespace iteration infrastructure introduced a few cycles ago. As reminder, the vfs makes it possible to iterate sequentially and bidirectionally through all mount namespaces on the system or all mount namespaces that the caller holds privilege over. This allow userspace to iterate over all mounts in all mount namespaces using the listmount() and statmount() system call. Each mount namespace has a unique identifier for the lifetime of the systems that is exposed to userspace. The network namespace also has a unique identifier working exactly the same way. This extends the concept to all other namespace types. The new nstree type makes it possible to lookup namespaces purely by their identifier and to walk the namespace list sequentially and bidirectionally for all namespace types, allowing userspace to iterate through all namespaces. Looking up namespaces in the namespace tree works completely locklessly. This also means we can move the mount namespace onto the generic infrastructure and remove a bunch of code and members from struct mnt_namespace itself. There's a bunch of stuff coming on top of this in the future but for now this uses the generic namespace tree to extend a concept introduced first for pidfs a few cycles ago. For a while now we have supported pidfs file handles for pidfds. This has proven to be very useful. This extends the concept to cover namespaces as well. It is possible to encode and decode namespace file handles using the common name_to_handle_at() and open_by_handle_at() apis. As with pidfs file handles, namespace file handles are exhaustive, meaning it is not required to actually hold a reference to nsfs in able to decode aka open_by_handle_at() a namespace file handle. Instead the FD_NSFS_ROOT constant can be passed which will let the kernel grab a reference to the root of nsfs internally and thus decode the file handle. Namespaces file descriptors can already be derived from pidfds which means they aren't subject to overmount protection bugs. IOW, it's irrelevant if the caller would not have access to an appropriate /proc/<pid>/ns/ directory as they could always just derive the namespace based on a pidfd already. It has the same advantage as pidfds. It's possible to reliably and for the lifetime of the system refer to a namespace without pinning any resources and to compare them trivially. Permission checking is kept simple. If the caller is located in the namespace the file handle refers to they are able to open it otherwise they must hold privilege over the owning namespace of the relevant namespace. The namespace file handle layout is exposed as uapi and has a stable and extensible format. For now it simply contains the namespace identifier, the namespace type, and the inode number. The stable format means that userspace may construct its own namespace file handles without going through name_to_handle_at() as they are already allowed for pidfs and cgroup file handles" * tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits) ns: drop assert ns: move ns type into struct ns_common nstree: make struct ns_tree private ns: add ns_debug() ns: simplify ns_common_init() further cgroup: add missing ns_common include ns: use inode initializer for initial namespaces selftests/namespaces: verify initial namespace inode numbers ns: rename to __ns_ref nsfs: port to ns_ref_*() helpers net: port to ns_ref_*() helpers uts: port to ns_ref_*() helpers ipv4: use check_net() net: use check_net() net-sysfs: use check_net() user: port to ns_ref_*() helpers time: port to ns_ref_*() helpers pid: port to ns_ref_*() helpers ipc: port to ns_ref_*() helpers cgroup: port to ns_ref_*() helpers ...
2025-09-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.17-rc8). Conflicts: drivers/net/can/spi/hi311x.c 6b6968084721 ("can: hi311x: fix null pointer dereference when resuming from sleep before interface was enabled") 27ce71e1ce81 ("net: WQ_PERCPU added to alloc_workqueue users") https://lore.kernel.org/72ce7599-1b5b-464a-a5de-228ff9724701@kernel.org net/smc/smc_loopback.c drivers/dibs/dibs_loopback.c a35c04de2565 ("net/smc: fix warning in smc_rx_splice() when calling get_page()") cc21191b584c ("dibs: Move data path to dibs layer") https://lore.kernel.org/74368a5c-48ac-4f8e-a198-40ec1ed3cf5f@kernel.org Adjacent changes: drivers/net/dsa/lantiq/lantiq_gswip.c c0054b25e2f1 ("net: dsa: lantiq_gswip: move gswip_add_single_port_br() call to port_setup()") 7a1eaef0a791 ("net: dsa: lantiq_gswip: support model-specific mac_select_pcs()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-25net: gro: remove unnecessary df checksRichard Gobert
Currently, packets with fixed IDs will be merged only if their don't-fragment bit is set. This restriction is unnecessary since packets without the don't-fragment bit will be forwarded as-is even if they were merged together. The merged packets will be segmented into their original forms before being forwarded, either by GSO or by TSO. The IDs will also remain identical unless NETIF_F_TSO_MANGLEID is set, in which case the IDs can become incrementing, which is also fine. Clean up the code by removing the unnecessary don't-fragment checks. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-5-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-25net: gso: restore ids of outer ip headers correctlyRichard Gobert
Currently, NETIF_F_TSO_MANGLEID indicates that the inner-most ID can be mangled. Outer IDs can always be mangled. Make GSO preserve outer IDs by default, with NETIF_F_TSO_MANGLEID allowing both inner and outer IDs to be mangled. This commit also modifies a few drivers that use SKB_GSO_FIXEDID directly. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> # for sfc Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-4-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-25net: gro: only merge packets with incrementing or fixed outer idsRichard Gobert
Only merge encapsulated packets if their outer IDs are either incrementing or fixed, just like for inner IDs and IDs of non-encapsulated packets. Add another ip_fixedid bit for a total of two bits: one for outer IDs (and for unencapsulated packets) and one for inner IDs. This commit preserves the current behavior of GSO where only the IDs of the inner-most headers are restored correctly. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-3-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-25net: gro: remove is_ipv6 from napi_gro_cbRichard Gobert
Remove is_ipv6 from napi_gro_cb and use sk->sk_family instead. This frees up space for another ip_fixedid bit that will be added in the next commit. udp_sock_create always creates either a AF_INET or a AF_INET6 socket, so using sk->sk_family is reliable. In IPv6-FOU, cfg->ipv6_v6only is always enabled. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-2-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23nexthop: Forbid FDB status change while nexthop is in a groupIdo Schimmel
The kernel forbids the creation of non-FDB nexthop groups with FDB nexthops: # ip nexthop add id 1 via 192.0.2.1 fdb # ip nexthop add id 2 group 1 Error: Non FDB nexthop group cannot have fdb nexthops. And vice versa: # ip nexthop add id 3 via 192.0.2.2 dev dummy1 # ip nexthop add id 4 group 3 fdb Error: FDB nexthop group can only have fdb nexthops. However, as long as no routes are pointing to a non-FDB nexthop group, the kernel allows changing the type of a nexthop from FDB to non-FDB and vice versa: # ip nexthop add id 5 via 192.0.2.2 dev dummy1 # ip nexthop add id 6 group 5 # ip nexthop replace id 5 via 192.0.2.2 fdb # echo $? 0 This configuration is invalid and can result in a NPD [1] since FDB nexthops are not associated with a nexthop device: # ip route add 198.51.100.1/32 nhid 6 # ping 198.51.100.1 Fix by preventing nexthop FDB status change while the nexthop is in a group: # ip nexthop add id 7 via 192.0.2.2 dev dummy1 # ip nexthop add id 8 group 7 # ip nexthop replace id 7 via 192.0.2.2 fdb Error: Cannot change nexthop FDB status while in a group. [1] BUG: kernel NULL pointer dereference, address: 00000000000003c0 [...] Oops: Oops: 0000 [#1] SMP CPU: 6 UID: 0 PID: 367 Comm: ping Not tainted 6.17.0-rc6-virtme-gb65678cacc03 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 RIP: 0010:fib_lookup_good_nhc+0x1e/0x80 [...] Call Trace: <TASK> fib_table_lookup+0x541/0x650 ip_route_output_key_hash_rcu+0x2ea/0x970 ip_route_output_key_hash+0x55/0x80 __ip4_datagram_connect+0x250/0x330 udp_connect+0x2b/0x60 __sys_connect+0x9c/0xd0 __x64_sys_connect+0x18/0x20 do_syscall_64+0xa4/0x2a0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Fixes: 38428d68719c ("nexthop: support for fdb ecmp nexthops") Reported-by: syzbot+6596516dd2b635ba2350@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68c9a4d2.050a0220.3c6139.0e63.GAE@google.com/ Tested-by: syzbot+6596516dd2b635ba2350@syzkaller.appspotmail.com Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250921150824.149157-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-23udp: remove busylock and add per NUMA queuesEric Dumazet
busylock was protecting UDP sockets against packet floods, but unfortunately was not protecting the host itself. Under stress, many cpus could spin while acquiring the busylock, and NIC had to drop packets. Or packets would be dropped in cpu backlog if RPS/RFS were in place. This patch replaces the busylock by intermediate lockless queues. (One queue per NUMA node). This means that fewer number of cpus have to acquire the UDP receive queue lock. Most of the cpus can either: - immediately drop the packet. - or queue it in their NUMA aware lockless queue. Then one of the cpu is chosen to process this lockless queue in a batch. The batch only contains packets that were cooked on the same NUMA node, thus with very limited latency impact. Tested: DDOS targeting a victim UDP socket, on a platform with 6 NUMA nodes (Intel(R) Xeon(R) 6985P-C) Before: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 1004179 0.0 Udp6InErrors 3117 0.0 Udp6RcvbufErrors 3117 0.0 After: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 1116633 0.0 Udp6InErrors 14197275 0.0 Udp6RcvbufErrors 14197275 0.0 We can see this host can now proces 14.2 M more packets per second while under attack, and the victim socket can receive 11 % more packets. I used a small bpftrace program measuring time (in us) spent in __udp_enqueue_schedule_skb(). Before: @udp_enqueue_us[398]: [0] 24901 |@@@ | [1] 63512 |@@@@@@@@@ | [2, 4) 344827 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [4, 8) 244673 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [8, 16) 54022 |@@@@@@@@ | [16, 32) 222134 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [32, 64) 232042 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [64, 128) 4219 | | [128, 256) 188 | | After: @udp_enqueue_us[398]: [0] 5608855 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [1] 1111277 |@@@@@@@@@@ | [2, 4) 501439 |@@@@ | [4, 8) 102921 | | [8, 16) 29895 | | [16, 32) 43500 | | [32, 64) 31552 | | [64, 128) 979 | | [128, 256) 13 | | Note that the remaining bottleneck for this platform is in udp_drops_inc() because we limited struct numa_drop_counters to only two nodes so far. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250922104240.2182559-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-23tcp: Update bind bucket state on port releaseJakub Sitnicki
Today, once an inet_bind_bucket enters a state where fastreuse >= 0 or fastreuseport >= 0 after a socket is explicitly bound to a port, it remains in that state until all sockets are removed and the bucket is destroyed. In this state, the bucket is skipped during ephemeral port selection in connect(). For applications using a reduced ephemeral port range (IP_LOCAL_PORT_RANGE socket option), this can cause faster port exhaustion since blocked buckets are excluded from reuse. The reason the bucket state isn't updated on port release is unclear. Possibly a performance trade-off to avoid scanning bucket owners, or just an oversight. Fix it by recalculating the bucket state when a socket releases a port. To limit overhead, each inet_bind2_bucket stores its own (fastreuse, fastreuseport) state. On port release, only the relevant port-addr bucket is scanned, and the overall state is derived from these. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250917-update-bind-bucket-state-on-unhash-v5-1-57168b661b47@cloudflare.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-22tcp: reclaim 8 bytes in struct request_sock_queueEric Dumazet
synflood_warned had to be u32 for xchg(), but ensuring atomicity is not really needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: move tcp_clean_acked to tcp_sock_read_tx groupEric Dumazet
tp->tcp_clean_acked is fetched in tx path when snd_una is updated. This field thus belongs to tcp_sock_read_tx group. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: move tcp->rcv_tstamp to tcp_sock_write_txrx groupEric Dumazet
tcp_ack() writes this field, it belongs to tcp_sock_write_txrx. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: remove CACHELINE_ASSERT_GROUP_SIZE() usesEric Dumazet
Maintaining the CACHELINE_ASSERT_GROUP_SIZE() uses for struct tcp_sock has been painful. This had little benefit, so remove them. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22net: move sk->sk_err_soft and sk->sk_sndbufEric Dumazet
sk->sk_sndbuf is read-mostly in tx path, so move it from sock_write_tx group to more appropriate sock_read_tx. sk->sk_err_soft was not identified previously, but is used from tcp_ack(). Move it to sock_write_tx group for better cache locality. Also change tcp_ack() to clear sk->sk_err_soft only if needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22net: replace use of system_wq with system_percpu_wqMarco Crivellari
Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. system_unbound_wq should be the default workqueue so as not to enforce locality constraints for random work whenever it's not required. Adding system_dfl_wq to encourage its use when unbound work should be used. The old system_unbound_wq will be kept for a few release cycles. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com> Link: https://patch.msgid.link/20250918142427.309519-3-marco.crivellari@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: Remove redundant sk_unhashed() in inet_unhash().Kuniyuki Iwashima
inet_unhash() checks sk_unhashed() twice at the entry and after locking ehash/lhash bucket. The former was somehow added redundantly by commit 4f9bf2a2f5aa ("tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH."). inet_unhash() is called for the full socket from 4 places, and it is always under lock_sock() or the socket is not yet published to other threads: 1. __sk_prot_rehash() -> called from inet_sk_reselect_saddr(), which has lockdep_sock_is_held() 2. sk_common_release() -> called when inet_create() or inet6_create() fail, then the socket is not yet published 3. tcp_set_state() -> calls tcp_call_bpf_2arg(), and tcp_call_bpf() has sock_owned_by_me() 4. inet_ctl_sock_create() -> creates a kernel socket and unhashes it immediately, but TCP socket is not hashed in sock_create_kern() (only SOCK_RAW is) So we do not need to check sk_unhashed() twice before/after ehash/lhash lock in inet_unhash(). Let's remove the 2nd one. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250919083706.1863217-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: Remove inet6_hash().Kuniyuki Iwashima
inet_hash() and inet6_hash() are exactly the same. Also, we do not need to export inet6_hash(). Let's consolidate the two into __inet_hash() and rename it to inet_hash(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250919083706.1863217-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: Remove osk from __inet_hash() arg.Kuniyuki Iwashima
__inet_hash() is called from inet_hash() and inet6_hash with osk NULL. Let's remove the 2nd arg from __inet_hash(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250919083706.1863217-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19net: ipv4: convert ip_rcv_options to drop reasonsAntoine Tenart
This converts the only path not returning drop reasons in ip_rcv_finish_core. Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250915091958.15382-4-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19net: ipv4: simplify drop reason handling in ip_rcv_finish_coreAntoine Tenart
Instead of setting the drop reason to SKB_DROP_REASON_NOT_SPECIFIED early and having to reset it each time it is overridden by a function returned value, just set the drop reason to the expected value before returning from ip_rcv_finish_core. Signed-off-by: Antoine Tenart <atenart@kernel.org> Link: https://patch.msgid.link/20250915091958.15382-3-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19net: ipv4: make udp_v4_early_demux explicitly return drop reasonAntoine Tenart
udp_v4_early_demux already returns drop reasons as it either returns 0 or ip_mc_validate_source, which itself returns drop reasons. Its return value is also already used as a drop reason itself. Makes this explicit by making it return drop reasons. Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250915091958.15382-2-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19tcp: prefer sk_skb_reason_drop()Eric Dumazet
Replace two calls to kfree_skb_reason() with sk_skb_reason_drop(). Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250918132007.325299-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19ipv4: use check_net()Christian Brauner
Don't directly acess the namespace count. There's even a dedicated helper for this. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.17-rc7). No conflicts. Adjacent changes: drivers/net/ethernet/mellanox/mlx5/core/en/fs.h 9536fbe10c9d ("net/mlx5e: Add PSP steering in local NIC RX") 7601a0a46216 ("net/mlx5e: Add a miss level for ipsec crypto offload") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-18Merge branch 'add-basic-psp-encryption-for-tcp-connections'Paolo Abeni
Daniel Zahka says: ================== add basic PSP encryption for TCP connections This is v13 of the PSP RFC [1] posted by Jakub Kicinski one year ago. General developments since v1 include a fork of packetdrill [2] with support for PSP added, as well as some test cases, and an implementation of PSP key exchange and connection upgrade [3] integrated into the fbthrift RPC library. Both [2] and [3] have been tested on server platforms with PSP-capable CX7 NICs. Below is the cover letter from the original RFC: Add support for PSP encryption of TCP connections. PSP is a protocol out of Google: https://github.com/google/psp/blob/main/doc/PSP_Arch_Spec.pdf which shares some similarities with IPsec. I added some more info in the first patch so I'll keep it short here. The protocol can work in multiple modes including tunneling. But I'm mostly interested in using it as TLS replacement because of its superior offload characteristics. So this patch does three things: - it adds "core" PSP code PSP is offload-centric, and requires some additional care and feeding, so first chunk of the code exposes device info. This part can be reused by PSP implementations in xfrm, tunneling etc. - TCP integration TLS style Reuse some of the existing concepts from TLS offload, such as attaching crypto state to a socket, marking skbs as "decrypted", egress validation. PSP does not prescribe key exchange protocols. To use PSP as a more efficient TLS offload we intend to perform a TLS handshake ("inline" in the same TCP connection) and negotiate switching to PSP based on capabilities of both endpoints. This is also why I'm not including a software implementation. Nobody would use it in production, software TLS is faster, it has larger crypto records. - mlx5 implementation That's mostly other people's work, not 100% sure those folks consider it ready hence the RFC in the title. But it works :) Not posted, queued a branch [4] are follow up pieces: - standard stats - netdevsim implementation and tests [1] https://lore.kernel.org/netdev/20240510030435.120935-1-kuba@kernel.org/ [2] https://github.com/danieldzahka/packetdrill [3] https://github.com/danieldzahka/fbthrift/tree/dzahka/psp [4] https://github.com/kuba-moo/linux/tree/psp Comments we intend to defer to future series: - we prefer to keep the version field in the tx-assoc netlink request, because it makes parsing keys require less state early on, but we are willing to change in the next version of this series. - using a static branch to wrap psp_enqueue_set_decrypted() and other functions called from tcp. - using INDIRECT_CALL for tls/psp in sk_validate_xmit_skb(). We prefer to address this in a dedicated patch series, so that this series does not need to modify the way tls_validate_xmit_skb() is declared and stubbed out. v12: https://lore.kernel.org/netdev/20250916000559.1320151-1-kuba@kernel.org/ v11: https://lore.kernel.org/20250911014735.118695-1-daniel.zahka@gmail.com v10: https://lore.kernel.org/netdev/20250828162953.2707727-1-daniel.zahka@gmail.com/ v9: https://lore.kernel.org/netdev/20250827155340.2738246-1-daniel.zahka@gmail.com/ v8: https://lore.kernel.org/netdev/20250825200112.1750547-1-daniel.zahka@gmail.com/ v7: https://lore.kernel.org/netdev/20250820113120.992829-1-daniel.zahka@gmail.com/ v6: https://lore.kernel.org/netdev/20250812003009.2455540-1-daniel.zahka@gmail.com/ v5: https://lore.kernel.org/netdev/20250723203454.519540-1-daniel.zahka@gmail.com/ v4: https://lore.kernel.org/netdev/20250716144551.3646755-1-daniel.zahka@gmail.com/ v3: https://lore.kernel.org/netdev/20250702171326.3265825-1-daniel.zahka@gmail.com/ v2: https://lore.kernel.org/netdev/20250625135210.2975231-1-daniel.zahka@gmail.com/ v1: https://lore.kernel.org/netdev/20240510030435.120935-1-kuba@kernel.org/ ================== Links: https://patch.msgid.link/20250917000954.859376-1-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- * add-basic-psp-encryption-for-tcp-connections: net/mlx5e: Implement PSP key_rotate operation net/mlx5e: Add Rx data path offload psp: provide decapsulation and receive helper for drivers net/mlx5e: Configure PSP Rx flow steering rules net/mlx5e: Add PSP steering in local NIC RX net/mlx5e: Implement PSP Tx data path psp: provide encapsulation helper for drivers net/mlx5e: Implement PSP operations .assoc_add and .assoc_del net/mlx5e: Support PSP offload functionality psp: track generations of device key net: psp: update the TCP MSS to reflect PSP packet overhead net: psp: add socket security association code net: tcp: allow tcp_timewait_sock to validate skbs before handing to device net: move sk_validate_xmit_skb() to net/core/dev.c psp: add op for rotation of device key tcp: add datapath logic for PSP with inline key exchange net: modify core data structures for PSP datapath support psp: base PSP device support psp: add documentation
2025-09-18net: psp: update the TCP MSS to reflect PSP packet overheadJakub Kicinski
PSP eats 40B of header space. Adjust MSS appropriately. We can either modify tcp_mtu_to_mss() / tcp_mss_to_mtu() or reuse icsk_ext_hdr_len. The former option is more TCP specific and has runtime overhead. The latter is a bit of a hack as PSP is not an ext_hdr. If one squints hard enough, UDP encap is just a more practical version of IPv6 exthdr, so go with the latter. Happy to change. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-10-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18net: tcp: allow tcp_timewait_sock to validate skbs before handing to deviceDaniel Zahka
Provide a callback to validate skb's originating from tcp timewait socks before passing to the device layer. Full socks have a sk_validate_xmit_skb member for checking that a device is capable of performing offloads required for transmitting an skb. With psp, tcp timewait socks will inherit the crypto state from their corresponding full socks. Any ACKs or RSTs that originate from a tcp timewait sock carrying psp state should be psp encapsulated. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-8-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: add datapath logic for PSP with inline key exchangeJakub Kicinski
Add validation points and state propagation to support PSP key exchange inline, on TCP connections. The expectation is that application will use some well established mechanism like TLS handshake to establish a secure channel over the connection and if both endpoints are PSP-capable - exchange and install PSP keys. Because the connection can existing in PSP-unsecured and PSP-secured state we need to make sure that there are no race conditions or retransmission leaks. On Tx - mark packets with the skb->decrypted bit when PSP key is at the enqueue time. Drivers should only encrypt packets with this bit set. This prevents retransmissions getting encrypted when original transmission was not. Similarly to TLS, we'll use sk->sk_validate_xmit_skb to make sure PSP skbs can't "escape" via a PSP-unaware device without being encrypted. On Rx - validation is done under socket lock. This moves the validation point later than xfrm, for example. Please see the documentation patch for more details on the flow of securing a connection, but for the purpose of this patch what's important is that we want to enforce the invariant that once connection is secured any skb in the receive queue has been encrypted with PSP. Add GRO and coalescing checks to prevent PSP authenticated data from being combined with cleartext data, or data with non-matching PSP state. On Rx, check skb's with psp_skb_coalesce_diff() at points before psp_sk_rx_policy_check(). After skb's are policy checked and on the socket receive queue, skb_cmp_decrypted() is sufficient for checking for coalescable PSP state. On Tx, tcp_write_collapse_fence() should be called when transitioning a socket into PSP Tx state to prevent data sent as cleartext from being coalesced with PSP encapsulated data. This change only adds the validation points, for ease of review. Subsequent change will add the ability to install keys, and flesh the enforcement logic out Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-5-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18net: modify core data structures for PSP datapath supportJakub Kicinski
Add pointers to psp data structures to core networking structs, and an SKB extension to carry the PSP information from the drivers to the socket layer. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-4-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: use skb_attempt_defer_free()Eric Dumazet
Move skb freeing from udp recvmsg() path to the cpu which allocated/received it, as TCP did in linux-5.17. This increases max thoughput by 20% to 30%, depending on number of BH producers. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250916160951.541279-11-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: make busylock per socketEric Dumazet
While having all spinlocks packed into an array was a space saver, this also caused NUMA imbalance and hash collisions. UDPv6 socket size becomes 1600 after this patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250916160951.541279-10-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: add udp_drops_inc() helperEric Dumazet
Generic sk_drops_inc() reads sk->sk_drop_counters. We know the precise location for UDP sockets. Move sk_drop_counters out of sock_read_rxtx so that sock_write_rxtx starts at a cache line boundary. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250916160951.541279-9-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>