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10 daysipv6: move the disable_ipv6_mod knob to core codeJakub Kicinski-8/+0
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>
2026-03-05net: ipv6: fix panic when IPv4 route references loopback IPv6 nexthopJiayuan Chen-5/+3
When a standalone IPv6 nexthop object is created with a loopback device (e.g., "ip -6 nexthop add id 100 dev lo"), fib6_nh_init() misclassifies it as a reject route. This is because nexthop objects have no destination prefix (fc_dst=::), causing fib6_is_reject() to match any loopback nexthop. The reject path skips fib_nh_common_init(), leaving nhc_pcpu_rth_output unallocated. If an IPv4 route later references this nexthop, __mkroute_output() dereferences NULL nhc_pcpu_rth_output and panics. Simplify the check in fib6_nh_init() to only match explicit reject routes (RTF_REJECT) instead of using fib6_is_reject(). The loopback promotion heuristic in fib6_is_reject() is handled separately by ip6_route_info_create_nh(). After this change, the three cases behave as follows: 1. Explicit reject route ("ip -6 route add unreachable 2001:db8::/64"): RTF_REJECT is set, enters reject path, skips fib_nh_common_init(). No behavior change. 2. Implicit loopback reject route ("ip -6 route add 2001:db8::/32 dev lo"): RTF_REJECT is not set, takes normal path, fib_nh_common_init() is called. ip6_route_info_create_nh() still promotes it to reject afterward. nhc_pcpu_rth_output is allocated but unused, which is harmless. 3. Standalone nexthop object ("ip -6 nexthop add id 100 dev lo"): RTF_REJECT is not set, takes normal path, fib_nh_common_init() is called. nhc_pcpu_rth_output is properly allocated, fixing the crash when IPv4 routes reference this nexthop. Suggested-by: Ido Schimmel <idosch@nvidia.com> Fixes: 493ced1ac47c ("ipv4: Allow routes to use nexthop objects") Reported-by: syzbot+334190e097a98a1b81bb@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/698f8482.a70a0220.2c38d7.00ca.GAE@google.com/T/ Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20260304113817.294966-2-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-04tcp: secure_seq: add back ports to TS offsetEric Dumazet-23/+25
This reverts 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") tcp_tw_recycle went away in 2017. Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways. One of them is to bring back TCP ports in TS offset randomization. As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset. Fixes: 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") Reported-by: Zhouyan Deng <dengzhouyan_nwpu@163.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Florian Westphal <fw@strlen.de> Link: https://patch.msgid.link/20260302205527.1982836-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-03net/tcp-md5: Fix MAC comparison to be constant-timeEric Biggers-1/+2
To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this. Fixes: cfb6eeb4c860 ("[TCP]: MD5 Signature Option (RFC2385) support.") Fixes: 658ddaaf6694 ("tcp: md5: RST: getting md5 key from listener") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> Link: https://patch.msgid.link/20260302203409.13388-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-03ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()Jakub Kicinski-1/+2
l3mdev_master_dev_rcu() can return NULL when the slave device is being un-slaved from a VRF. All other callers deal with this, but we lost the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address"). KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Call Trace: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) I was tempted to rework the un-slaving code to clear the flag first and insert synchronize_rcu() before we remove the upper. But looks like the explicit fallback to loopback_dev is an established pattern. And I guess avoiding the synchronize_rcu() is nice, too. Fixes: 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address") Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20260301194548.927324-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27inet: annotate data-races around isk->inet_numEric Dumazet-1/+2
UDP/TCP lookups are using RCU, thus isk->inet_num accesses should use READ_ONCE() and WRITE_ONCE() where needed. Fixes: 3ab5aee7fe84 ("net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260225203545.1512417-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-26Merge tag 'net-7.0-rc2' of ↵Linus Torvalds-60/+48
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from IPsec, Bluetooth and netfilter Current release - regressions: - wifi: fix dev_alloc_name() return value check - rds: fix recursive lock in rds_tcp_conn_slots_available Current release - new code bugs: - vsock: lock down child_ns_mode as write-once Previous releases - regressions: - core: - do not pass flow_id to set_rps_cpu() - consume xmit errors of GSO frames - netconsole: avoid OOB reads, msg is not nul-terminated - netfilter: h323: fix OOB read in decode_choice() - tcp: re-enable acceptance of FIN packets when RWIN is 0 - udplite: fix null-ptr-deref in __udp_enqueue_schedule_skb(). - wifi: brcmfmac: fix potential kernel oops when probe fails - phy: register phy led_triggers during probe to avoid AB-BA deadlock - eth: - bnxt_en: fix deleting of Ntuple filters - wan: farsync: fix use-after-free bugs caused by unfinished tasklets - xscale: check for PTP support properly Previous releases - always broken: - tcp: fix potential race in tcp_v6_syn_recv_sock() - kcm: fix zero-frag skb in frag_list on partial sendmsg error - xfrm: - fix race condition in espintcp_close() - always flush state and policy upon NETDEV_UNREGISTER event - bluetooth: - purge error queues in socket destructors - fix response to L2CAP_ECRED_CONN_REQ - eth: - mlx5: - fix circular locking dependency in dump - fix "scheduling while atomic" in IPsec MAC address query - gve: fix incorrect buffer cleanup for QPL - team: avoid NETDEV_CHANGEMTU event when unregistering slave - usb: validate USB endpoints" * tag 'net-7.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits) netfilter: nf_conntrack_h323: fix OOB read in decode_choice() dpaa2-switch: validate num_ifs to prevent out-of-bounds write net: consume xmit errors of GSO frames vsock: document write-once behavior of the child_ns_mode sysctl vsock: lock down child_ns_mode as write-once selftests/vsock: change tests to respect write-once child ns mode net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query net/mlx5: Fix missing devlink lock in SRIOV enable error path net/mlx5: E-switch, Clear legacy flag when moving to switchdev net/mlx5: LAG, disable MPESW in lag_disable_change() net/mlx5: DR, Fix circular locking dependency in dump selftests: team: Add a reference count leak test team: avoid NETDEV_CHANGEMTU event when unregistering slave net: mana: Fix double destroy_workqueue on service rescan PCI path MAINTAINERS: Update maintainer entry for QUALCOMM ETHQOS ETHERNET DRIVER dpll: zl3073x: Remove redundant cleanup in devm_dpll_init() selftests/net: packetdrill: Verify acceptance of FIN packets when RWIN is 0 tcp: re-enable acceptance of FIN packets when RWIN is 0 vsock: Use container_of() to get net namespace in sysctl handlers net: usb: kaweth: validate USB endpoints ...
2026-02-22Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL usesKees Cook-2/+2
Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert more 'alloc_obj' cases to default GFP_KERNEL argumentsLinus Torvalds-8/+4
This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds-23/+23
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook-56/+54
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-20udplite: Fix null-ptr-deref in __udp_enqueue_schedule_skb().Kuniyuki Iwashima-2/+1
syzbot reported null-ptr-deref of udp_sk(sk)->udp_prod_queue. [0] Since the cited commit, udp_lib_init_sock() can fail, as can udp_init_sock() and udpv6_init_sock(). Let's handle the error in udplite_sk_init() and udplitev6_sk_init(). [0]: BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:82 [inline] BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: null-ptr-deref in __udp_enqueue_schedule_skb+0x151/0x1480 net/ipv4/udp.c:1719 Read of size 4 at addr 0000000000000008 by task syz.2.18/2944 CPU: 1 UID: 0 PID: 2944 Comm: syz.2.18 Not tainted syzkaller #0 PREEMPTLAZY Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: <IRQ> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 kasan_report+0xa2/0xe0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:82 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] __udp_enqueue_schedule_skb+0x151/0x1480 net/ipv4/udp.c:1719 __udpv6_queue_rcv_skb net/ipv6/udp.c:795 [inline] udpv6_queue_rcv_one_skb+0xa2e/0x1ad0 net/ipv6/udp.c:906 udp6_unicast_rcv_skb+0x227/0x380 net/ipv6/udp.c:1064 ip6_protocol_deliver_rcu+0xe17/0x1540 net/ipv6/ip6_input.c:438 ip6_input_finish+0x191/0x350 net/ipv6/ip6_input.c:489 NF_HOOK+0x354/0x3f0 include/linux/netfilter.h:318 ip6_input+0x16c/0x2b0 net/ipv6/ip6_input.c:500 NF_HOOK+0x354/0x3f0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6149 [inline] __netif_receive_skb+0xd3/0x370 net/core/dev.c:6262 process_backlog+0x4d6/0x1160 net/core/dev.c:6614 __napi_poll+0xae/0x320 net/core/dev.c:7678 napi_poll net/core/dev.c:7741 [inline] net_rx_action+0x60d/0xdc0 net/core/dev.c:7893 handle_softirqs+0x209/0x8d0 kernel/softirq.c:622 do_softirq+0x52/0x90 kernel/softirq.c:523 </IRQ> <TASK> __local_bh_enable_ip+0xe7/0x120 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline] __dev_queue_xmit+0x109c/0x2dc0 net/core/dev.c:4856 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x158/0x4e0 net/ipv6/ip6_output.c:219 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x342/0x580 net/ipv6/ip6_output.c:246 ip6_send_skb+0x1d7/0x3c0 net/ipv6/ip6_output.c:1984 udp_v6_send_skb+0x9a5/0x1770 net/ipv6/udp.c:1442 udp_v6_push_pending_frames+0xa2/0x140 net/ipv6/udp.c:1469 udpv6_sendmsg+0xfe0/0x2830 net/ipv6/udp.c:1759 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xe5/0x270 net/socket.c:742 __sys_sendto+0x3eb/0x580 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2209 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0xf20 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f67b4d9c629 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f67b5c98028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f67b5015fa0 RCX: 00007f67b4d9c629 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f67b4e32b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000040000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f67b5016038 R14: 00007f67b5015fa0 R15: 00007ffe3cb66dd8 </TASK> Fixes: b650bf0977d3 ("udp: remove busylock and add per NUMA queues") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260219173142.310741-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-20Merge tag 'ipsec-2026-02-20' of ↵Jakub Kicinski-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2026-02-20 1) Check the value of ipv6_dev_get_saddr() to fix an uninitialized saddr in xfrm6_get_saddr(). From Jiayuan Chen. 2) Skip the templates check for packet offload in tunnel mode. Is was already done by the hardware and causes an unexpected XfrmInTmplMismatch increase. From Leon Romanovsky. 3) Fix a unregister_netdevice stall due to not dropped refcounts by always flushing xfrm state and policy on a NETDEV_UNREGISTER event. From Tetsuo Handa. * tag 'ipsec-2026-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: always flush state and policy upon NETDEV_UNREGISTER event xfrm: skip templates check for packet offload tunnel mode xfrm6: fix uninitialized saddr in xfrm6_get_saddr() ==================== Link: https://patch.msgid.link/20260220094133.14219-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-19tcp: fix potential race in tcp_v6_syn_recv_sock()Eric Dumazet-56/+42
Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock() is done too late. After tcp_v4_syn_recv_sock(), the child socket is already visible from TCP ehash table and other cpus might use it. Since newinet->pinet6 is still pointing to the listener ipv6_pinfo bad things can happen as syzbot found. Move the problematic code in tcp_v6_mapped_child_init() and call this new helper from tcp_v4_syn_recv_sock() before the ehash insertion. This allows the removal of one tcp_sync_mss(), since tcp_v4_syn_recv_sock() will call it with the correct context. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+937b5bbb6a815b3e5d0b@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/69949275.050a0220.2eeac1.0145.GAE@google.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260217161205.2079883-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-18ipv6: icmp: icmpv6_xrlim_allow() optimization if net.ipv6.icmp.ratelimit is zeroEric Dumazet-2/+6
If net.ipv6.icmp.ratelimit is zero we do not have to call inet_getpeer_v6() and inet_peer_xrlim_allow(). Both can be very expensive under DDOS. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260216142832.3834174-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-18ipv6: icmp: remove obsolete code in icmpv6_xrlim_allow()Eric Dumazet-7/+2
Following part was needed before the blamed commit, because inet_getpeer_v6() second argument was the prefix. /* Give more bandwidth to wider prefixes. */ if (rt->rt6i_dst.plen < 128) tmo >>= ((128 - rt->rt6i_dst.plen)>>5); Now inet_getpeer_v6() retrieves hosts, we need to remove @tmo adjustement or wider prefixes likes /24 allow 8x more ICMP to be sent for a given ratelimit. As we had this issue for a while, this patch changes net.ipv6.icmp.ratelimit default value from 1000ms to 100ms to avoid potential regressions. Also add a READ_ONCE() when reading net->ipv6.sysctl.icmpv6_time. Fixes: fd0273d7939f ("ipv6: Remove external dependency on rt6i_dst and rt6i_src") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Cc: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20260216142832.3834174-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-13ipv6: Fix out-of-bound access in fib6_add_rt2node().Kuniyuki Iwashima-1/+1
syzbot reported out-of-bound read in fib6_add_rt2node(). [0] When IPv6 route is created with RTA_NH_ID, struct fib6_info does not have the trailing struct fib6_nh. The cited commit started to check !iter->fib6_nh->fib_nh_gw_family to ensure that rt6_qualify_for_ecmp() will return false for iter. If iter->nh is not NULL, rt6_qualify_for_ecmp() returns false anyway. Let's check iter->nh before reading iter->fib6_nh and avoid OOB read. [0]: BUG: KASAN: slab-out-of-bounds in fib6_add_rt2node+0x349c/0x3500 net/ipv6/ip6_fib.c:1142 Read of size 1 at addr ffff8880384ba6de by task syz.0.18/5500 CPU: 0 UID: 0 PID: 5500 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 fib6_add_rt2node+0x349c/0x3500 net/ipv6/ip6_fib.c:1142 fib6_add_rt2node_nh net/ipv6/ip6_fib.c:1363 [inline] fib6_add+0x910/0x18c0 net/ipv6/ip6_fib.c:1531 __ip6_ins_rt net/ipv6/route.c:1351 [inline] ip6_route_add+0xde/0x1b0 net/ipv6/route.c:3957 inet6_rtm_newroute+0x268/0x19e0 net/ipv6/route.c:5660 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9316b9aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd8809b678 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f9316e15fa0 RCX: 00007f9316b9aeb9 RDX: 0000000000000000 RSI: 0000200000004380 RDI: 0000000000000003 RBP: 00007f9316c08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9316e15fac R14: 00007f9316e15fa0 R15: 00007f9316e15fa0 </TASK> Allocated by task 5499: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_noprof+0x40c/0x7e0 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3820 ip6_route_add+0x49/0x1b0 net/ipv6/route.c:3949 inet6_rtm_newroute+0x268/0x19e0 net/ipv6/route.c:5660 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: bbf4a17ad9ff ("ipv6: Fix ECMP sibling count mismatch when clearing RTF_ADDRCONF") Reported-by: syzbot+707d6a5da1ab9e0c6f9d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/698cbfba.050a0220.2eeac1.009d.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Shigeru Yoshida <syoshida@redhat.com> Link: https://patch.msgid.link/20260211175133.3657034-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-13ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()Qanux-9/+20
On the receive path, __ioam6_fill_trace_data() uses trace->nodelen to decide how much data to write for each node. It trusts this field as-is from the incoming packet, with no consistency check against trace->type (the 24-bit field that tells which data items are present). A crafted packet can set nodelen=0 while setting type bits 0-21, causing the function to write ~100 bytes past the allocated region (into skb_shared_info), which corrupts adjacent heap memory and leads to a kernel panic. Add a shared helper ioam6_trace_compute_nodelen() in ioam6.c to derive the expected nodelen from the type field, and use it: - in ioam6_iptunnel.c (send path, existing validation) to replace the open-coded computation; - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose nodelen is inconsistent with the type field, before any data is written. Per RFC 9197, bits 12-21 are each short (4-octet) fields, so they are included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to 0xff1ffc00). Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace") Cc: stable@vger.kernel.org Signed-off-by: Junxi Qian <qjx1298677004@gmail.com> Reviewed-by: Justin Iurman <justin.iurman@gmail.com> Link: https://patch.msgid.link/20260211040412.86195-1-qjx1298677004@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netPaolo Abeni-0/+6
Merge in late fixes in preparation for the net-next PR. Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10tcp: inet6_csk_xmit() optimizationEric Dumazet-15/+15
After prior patches, inet6_csk_xmit() can reuse inet->cork.fl.u.ip6 if __sk_dst_check() returns a valid dst. Otherwise call inet6_csk_route_socket() to refresh inet->cork.fl.u.ip6 content and get a new dst. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260206173426.1638518-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10tcp: populate inet->cork.fl.u.ip6 in tcp_v6_syn_recv_sock()Eric Dumazet-14/+14
As explained in commit 85d05e281712 ("ipv6: change inet6_sk_rebuild_header() to use inet->cork.fl.u.ip6"): TCP v6 spends a good amount of time rebuilding a fresh fl6 at each transmit in inet6_csk_xmit()/inet6_csk_route_socket(). TCP v4 caches the information in inet->cork.fl.u.ip4 instead. After this patch, passive TCP ipv6 flows have correctly initialized inet->cork.fl.u.ip6 structure. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260206173426.1638518-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10tcp: populate inet->cork.fl.u.ip6 in tcp_v6_connect()Eric Dumazet-23/+24
Instead of using private @fl6 and @final variables use respectively inet->cork.fl.u.ip6 and np->final. As explained in commit 85d05e281712 ("ipv6: change inet6_sk_rebuild_header() to use inet->cork.fl.u.ip6"): TCP v6 spends a good amount of time rebuilding a fresh fl6 at each transmit in inet6_csk_xmit()/inet6_csk_route_socket(). TCP v4 caches the information in inet->cork.fl.u.ip4 instead. After this patch, active TCP ipv6 flows have correctly initialized inet->cork.fl.u.ip6 structure. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260206173426.1638518-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10ipv6: inet6_csk_xmit() and inet6_csk_update_pmtu() use inet->cork.fl.u.ip6Eric Dumazet-9/+11
Convert inet6_csk_route_socket() to use np->final instead of an automatic variable to get rid of a stack canary. Convert inet6_csk_xmit() and inet6_csk_update_pmtu() to use inet->cork.fl.u.ip6 instead of @fl6 automatic variable. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260206173426.1638518-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10ipv6: use inet->cork.fl.u.ip6 and np->final in ip6_datagram_dst_update()Eric Dumazet-10/+11
Get rid of @fl6 and &final variables in ip6_datagram_dst_update(). Use instead inet->cork.fl.u.ip6 and np->final so that a stack canary is no longer needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260206173426.1638518-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10ipv6: use np->final in inet6_sk_rebuild_header()Eric Dumazet-2/+2
Instead of using an automatic variable, use np->final to get rid of the stack canary in inet6_sk_rebuild_header(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260206173426.1638518-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06net/ipv6: Remove jumbo_remove step from TX pathAlice Mikityanska-4/+1
Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove unnecessary steps from the GSO TX path, that used to check and remove HBH. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260205133925.526371-5-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06net/ipv6: Drop HBH for BIG TCP on RX sideAlice Mikityanska-27/+1
Complementary to the previous commit, stop inserting HBH when building BIG TCP GRO SKBs. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260205133925.526371-4-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06net/ipv6: Drop HBH for BIG TCP on TX sideAlice Mikityanska-17/+3
BIG TCP IPv6 inserts a hop-by-hop extension header to indicate the real IPv6 payload length when it doesn't fit into the 16-bit field in the IPv6 header itself. While it helps tools parse the packet, it also requires every driver that supports TSO and BIG TCP to remove this 8-byte extension header. It might not sound that bad until we try to apply it to tunneled traffic. Currently, the drivers don't attempt to strip HBH if skb->encapsulation = 1. Moreover, trying to do so would require dissecting different tunnel protocols and making corresponding adjustments on case-by-case basis, which would slow down the fastpath (potentially also requiring adjusting checksums in outer headers). At the same time, BIG TCP IPv4 doesn't insert any extra headers and just calculates the payload length from skb->len, significantly simplifying implementing BIG TCP for tunnels. Stop inserting HBH when building BIG TCP GSO SKBs. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260205133925.526371-3-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06net/ipv6: Introduce payload_len helpersAlice Mikityanska-11/+5
The next commits will transition away from using the hop-by-hop extension header to encode packet length for BIG TCP. Add wrappers around ip6->payload_len that return the actual value if it's non-zero, and calculate it from skb->len if payload_len is set to zero (and a symmetrical setter). The new helpers are used wherever the surrounding code supports the hop-by-hop jumbo header for BIG TCP IPv6, or the corresponding IPv4 code uses skb_ip_totlen (e.g., in include/net/netfilter/nf_tables_ipv6.h). No behavioral change in this commit. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260205133925.526371-2-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06ipv6: do not use skb_header_pointer() in icmpv6_filter()Eric Dumazet-16/+16
Prefer pskb_may_pull() to avoid a stack canary in raw6_local_deliver(). Note: skb->head can change, hence we reload ip6h pointer in ipv6_raw_deliver() $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-86 (-86) Function old new delta raw6_local_deliver 780 694 -86 Total: Before=24889784, After=24889698, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260205211909.4115285-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-05inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMPEric Dumazet-0/+6
Yizhou Zhao reported that simply having one RAW socket on protocol IPPROTO_RAW (255) was dangerous. socket(AF_INET, SOCK_RAW, 255); A malicious incoming ICMP packet can set the protocol field to 255 and match this socket, leading to FNHE cache changes. inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST") pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner "man 7 raw" states: A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able to send any IP protocol that is specified in the passed header. Receiving of all IP protocols via IPPROTO_RAW is not possible using raw sockets. Make sure we drop these malicious packets. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn> Link: https://lore.kernel.org/netdev/20251109134600.292125-1-zhaoyz24@mails.tsinghua.edu.cn/ Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260203192509.682208-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski-1/+2
Cross-merge networking fixes after downstream PR (net-6.19-rc9). No adjacent changes, conflicts: drivers/net/ethernet/spacemit/k1_emac.c 3125fc1701694 ("net: spacemit: k1-emac: fix jumbo frame support") f66086798f91f ("net: spacemit: Remove broken flow control support") https://lore.kernel.org/aYIysFIE9ooavWia@sirena.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-05ipv6: change inet6_sk_rebuild_header() to use inet->cork.fl.u.ip6Eric Dumazet-30/+27
TCP v6 spends a good amount of time rebuilding a fresh fl6 at each transmit in inet6_csk_xmit()/inet6_csk_route_socket(). TCP v4 caches the information in inet->cork.fl.u.ip4 instead. This patch is a first step converting IPv6 to the same strategy: Before this patch inet6_sk_rebuild_header() only validated/rebuilt a dst. Automatic variable @fl6 content was lost. After this patch inet6_sk_rebuild_header() also initializes inet->cork.fl.u.ip6, which can be reused in the future. This makes inet6_sk_rebuild_header() very similar to inet_sk_rebuild_header(). Also remove the EXPORT_SYMBOL_GPL(), inet6_sk_rebuild_header() is not called from any module. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260204163035.4123817-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-05ipv6: Fix ECMP sibling count mismatch when clearing RTF_ADDRCONFShigeru Yoshida-1/+2
syzbot reported a kernel BUG in fib6_add_rt2node() when adding an IPv6 route. [0] Commit f72514b3c569 ("ipv6: clear RA flags when adding a static route") introduced logic to clear RTF_ADDRCONF from existing routes when a static route with the same nexthop is added. However, this causes a problem when the existing route has a gateway. When RTF_ADDRCONF is cleared from a route that has a gateway, that route becomes eligible for ECMP, i.e. rt6_qualify_for_ecmp() returns true. The issue is that this route was never added to the fib6_siblings list. This leads to a mismatch between the following counts: - The sibling count computed by iterating fib6_next chain, which includes the newly ECMP-eligible route - The actual siblings in fib6_siblings list, which does not include that route When a subsequent ECMP route is added, fib6_add_rt2node() hits BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings) because the counts don't match. Fix this by only clearing RTF_ADDRCONF when the existing route does not have a gateway. Routes without a gateway cannot qualify for ECMP anyway (rt6_qualify_for_ecmp() requires fib_nh_gw_family), so clearing RTF_ADDRCONF on them is safe and matches the original intent of the commit. [0]: kernel BUG at net/ipv6/ip6_fib.c:1217! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 6010 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:fib6_add_rt2node+0x3433/0x3470 net/ipv6/ip6_fib.c:1217 [...] Call Trace: <TASK> fib6_add+0x8da/0x18a0 net/ipv6/ip6_fib.c:1532 __ip6_ins_rt net/ipv6/route.c:1351 [inline] ip6_route_add+0xde/0x1b0 net/ipv6/route.c:3946 ipv6_route_ioctl+0x35c/0x480 net/ipv6/route.c:4571 inet6_ioctl+0x219/0x280 net/ipv6/af_inet6.c:577 sock_do_ioctl+0xdc/0x300 net/socket.c:1245 sock_ioctl+0x576/0x790 net/socket.c:1366 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: f72514b3c569 ("ipv6: clear RA flags when adding a static route") Reported-by: syzbot+cb809def1baaac68ab92@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cb809def1baaac68ab92 Tested-by: syzbot+cb809def1baaac68ab92@syzkaller.appspotmail.com Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260204095837.1285552-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv6: colocate inet6_cork in inet_cork_fullEric Dumazet-29/+28
All inet6_cork users also use one inet_cork_full. Reduce number of parameters and increase data locality. This saves ~275 bytes of code on x86_64. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv4: use dst4_mtu() instead of dst_mtu()Eric Dumazet-1/+1
When we expect an IPv4 dst, use dst4_mtu() instead of dst_mtu() to save some code space. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv6: use dst6_mtu() instead of dst_mtu()Eric Dumazet-16/+19
When we expect an IPv6 dst, use dst6_mtu() instead of dst_mtu() to save some code space. Due to current dst6_mtu() implementation, only convert users in IPv6 stack. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv6: use SKB_DROP_REASON_PKT_TOO_BIG in ip6_xmit()Eric Dumazet-1/+1
When a too big packet is dropped, use SKB_DROP_REASON_PKT_TOO_BIG. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv6: use __skb_push() in ip6_xmit()Eric Dumazet-2/+2
ip6_xmit() makes sure there is enough headroom in the skb, it can uses __skb_push() instead of the out-of-line skb_push(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv6: add some unlikely()/likely() clauses in ip6_output.cEric Dumazet-12/+12
1) daddr is unlikely a multicast in ip6_finish_output2(). 2) ip6_finish_output_gso_slowpath_drop() should not be called often. 3) ip6_fragment() should not be called often. 4) opt is unlikely to be set. 5) ip6_xmit() and ip6_forward() mostly sends not too big packets. 6) Most __ip6_make_skb() calls are for UDP packets, not ICMPV6 ones. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv6: pass proto by value to ipv6_push_nfrag_opts() and ipv6_push_frag_opts()Eric Dumazet-35/+41
With CONFIG_STACKPROTECTOR_STRONG=y, it is better to avoid passing a pointer to an automatic variable. Change these exported functions to return 'u8 proto' instead of void. - ipv6_push_nfrag_opts() - ipv6_push_frag_opts() For instance, replace ipv6_push_frag_opts(skb, opt, &proto); with: proto = ipv6_push_frag_opts(skb, opt, proto); Note that even after this change, ip6_xmit() has to use a stack canary because of @first_hop variable. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02xfrm6: fix uninitialized saddr in xfrm6_get_saddr()Jiayuan Chen-2/+5
xfrm6_get_saddr() does not check the return value of ipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable source address (returns -EADDRNOTAVAIL), saddr->in6 is left uninitialized, but xfrm6_get_saddr() still returns 0 (success). This causes the caller xfrm_tmpl_resolve_one() to use the uninitialized address in xfrm_state_find(), triggering KMSAN warning: ===================================================== BUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940 xfrm_state_find+0x2424/0xa940 xfrm_resolve_and_create_bundle+0x906/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 xfrm_lookup_route+0x63/0x2b0 ip_route_output_flow+0x1ce/0x270 udp_sendmsg+0x2ce1/0x3400 inet_sendmsg+0x1ef/0x2a0 __sock_sendmsg+0x278/0x3d0 __sys_sendto+0x593/0x720 __x64_sys_sendto+0x130/0x200 x64_sys_call+0x332b/0x3e70 do_syscall_64+0xd3/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable tmp.i.i created at: xfrm_resolve_and_create_bundle+0x3e3/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 ===================================================== Fix by checking the return value of ipv6_dev_get_saddr() and propagating the error. Fixes: a1e59abf8249 ("[XFRM]: Fix wildcard as tunnel source") Reported-by: syzbot+e136d86d34b42399a8b1@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68bf1024.a70a0220.7a912.02c2.GAE@google.com/T/ Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com> Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-01-30tcp: reduce tcp sockets size by one cache lineEric Dumazet-0/+2
By default, when a kmem_cache is created with SLAB_TYPESAFE_BY_RCU, slub has to use extra storage for the freelist pointer after each object, because slub assumes that any bit in the object can be used by RCU readers. Because proto_register() is also using SLAB_HWCACHE_ALIGN, this forces slub to use one extra cache line per object. We can instead put the slub freelist anywhere in the object, granted the concurrent RCU readers are not supposed to use the pointer value. Add a new (struct sock)sk_freeptr field, in an union with sk_rcu: No RCU readers would need to look at sk_rcu, which is only used at free phase. Tested: grep . /sys/kernel/slab/TCP/{object_size,slab_size,objs_per_slab} grep . /sys/kernel/slab/TCPv6/{object_size,slab_size,objs_per_slab} Before: /sys/kernel/slab/TCP/object_size:2368 /sys/kernel/slab/TCP/slab_size:2432 /sys/kernel/slab/TCP/objs_per_slab:13 /sys/kernel/slab/TCPv6/object_size:2496 /sys/kernel/slab/TCPv6/slab_size:2560 /sys/kernel/slab/TCPv6/objs_per_slab:12 After this patch, we can pack one more TCPv6 object per slab, and object_size == slab_size. /sys/kernel/slab/TCP/object_size:2368 /sys/kernel/slab/TCP/slab_size:2368 /sys/kernel/slab/TCP/objs_per_slab:13 /sys/kernel/slab/TCPv6/object_size:2496 /sys/kernel/slab/TCPv6/slab_size:2496 /sys/kernel/slab/TCPv6/objs_per_slab:13 Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260129153458.4163797-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-29ipv6: optimize fl6_update_dst()Eric Dumazet-7/+7
fl6_update_dst() is called for every TCP (and others) transmit, and is a nop for common cases. Split it in two parts : 1) fl6_update_dst() inline helper, small and fast. 2) __fl6_update_dst() for the exception, out of line. Small size increase to get better TX performance. $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 2/2 grow/shrink: 8/0 up/down: 296/-125 (171) Function old new delta __fl6_update_dst - 104 +104 rawv6_sendmsg 2244 2284 +40 udpv6_sendmsg 3013 3043 +30 tcp_v6_connect 1514 1534 +20 cookie_v6_check 1501 1519 +18 ip6_datagram_dst_update 673 690 +17 inet6_sk_rebuild_header 499 516 +17 inet6_csk_route_socket 507 524 +17 inet6_csk_route_req 343 360 +17 __pfx___fl6_update_dst - 16 +16 __pfx_fl6_update_dst 16 - -16 fl6_update_dst 109 - -109 Total: Before=22570304, After=22570475, chg +0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260128185548.3738781-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski-2/+5
Cross-merge networking fixes after downstream PR (net-6.19-rc8). No adjacent changes, conflicts: drivers/net/ethernet/spacemit/k1_emac.c 2c84959167d64 ("net: spacemit: Check for netif_carrier_ok() in emac_stats_update()") f66086798f91f ("net: spacemit: Remove broken flow control support") https://lore.kernel.org/aXjAqZA3iEWD_DGM@sirena.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-29net: fix segmentation of forwarding fraglist GROJibin Zhang-1/+2
This patch enhances GSO segment handling by properly checking the SKB_GSO_DODGY flag for frag_list GSO packets, addressing low throughput issues observed when a station accesses IPv4 servers via hotspots with an IPv6-only upstream interface. Specifically, it fixes a bug in GSO segmentation when forwarding GRO packets containing a frag_list. The function skb_segment_list cannot correctly process GRO skbs that have been converted by XLAT, since XLAT only translates the header of the head skb. Consequently, skbs in the frag_list may remain untranslated, resulting in protocol inconsistencies and reduced throughput. To address this, the patch explicitly sets the SKB_GSO_DODGY flag for GSO packets in XLAT's IPv4/IPv6 protocol translation helpers (bpf_skb_proto_4_to_6 and bpf_skb_proto_6_to_4). This marks GSO packets as potentially modified after protocol translation. As a result, GSO segmentation will avoid using skb_segment_list and instead falls back to skb_segment for packets with the SKB_GSO_DODGY flag. This ensures that only safe and fully translated frag_list packets are processed by skb_segment_list, resolving protocol inconsistencies and improving throughput when forwarding GRO packets converted by XLAT. Signed-off-by: Jibin Zhang <jibin.zhang@mediatek.com> Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260126152114.1211-1-jibin.zhang@mediatek.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-29netfilter: flowtable: Add IP6IP6 rx sw accelerationLorenzo Bianconi-0/+27
Introduce sw acceleration for rx path of IP6IP6 tunnels relying on the netfilter flowtable infrastructure. Subsequent patches will add sw acceleration for IP6IP6 tunnels tx path. IP6IP6 rx sw acceleration can be tested running the following scenario where the traffic is forwarded between two NICs (eth0 and eth1) and an IP6IP6 tunnel is used to access a remote site (using eth1 as the underlay device): ETH0 -- TUN0 <==> ETH1 -- [IP network] -- TUN1 (2001:db8:3::2) $ip addr show 6: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:00:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet6 2001:db8:1::2/64 scope global nodad valid_lft forever preferred_lft forever 7: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:11:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet6 2001:db8:2::1/64 scope global nodad valid_lft forever preferred_lft forever 8: tun0@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1480 qdisc noqueue state UNKNOWN group default qlen 1000 link/tunnel6 2001:db8:2::1 peer 2001:db8:2::2 permaddr ce9c:2940:7dcc:: inet6 2002:db8:1::1/64 scope global nodad valid_lft forever preferred_lft forever $ip -6 route show 2001:db8:1::/64 dev eth0 proto kernel metric 256 pref medium 2001:db8:2::/64 dev eth1 proto kernel metric 256 pref medium 2002:db8:1::/64 dev tun0 proto kernel metric 256 pref medium default via 2002:db8:1::2 dev tun0 metric 1024 pref medium $nft list ruleset table inet filter { flowtable ft { hook ingress priority filter devices = { eth0, eth1 } } chain forward { type filter hook forward priority filter; policy accept; meta l4proto { tcp, udp } flow add @ft } } Reproducing the scenario described above using veths I got the following results: - TCP stream received from the IPIP tunnel: - net-next: (baseline) ~ 81Gbps - net-next + IP6IP6 flowtbale support: ~112Gbps Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-01-28ipv6: remove __inet6_csk_dst_check()Eric Dumazet-7/+1
__inet6_csk_dst_check() is a very simple wrapper with no value, it is used only once. Directly use __sk_dst_check(). Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260127211203.1524339-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-27ipv6: Switch to higher-level SHA-1 functionsEric Biggers-8/+13
There's now a proper SHA-1 API that follows the usual conventions for hash function APIs: sha1_init(), sha1_update(), sha1_final(), sha1(). The only remaining user of the older low-level SHA-1 API, sha1_init_raw() and sha1_transform(), is ipv6_generate_stable_address(). I'd like to remove this older API, which is too low-level. Unfortunately, ipv6_generate_stable_address() does in fact skip the SHA-1 finalization for some reason. So the values it computes are not standard SHA-1 values, and it sort of does want the low-level API. Still, it's still possible to use the higher-level functions sha1_init() and sha1_update() to get the same result, provided that the resulting state is used directly, skipping sha1_final(). So, let's do that instead. This will allow removing the low-level API. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Eric Biggers <ebiggers@kernel.org> Acked-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20260123051656.396371-2-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-25ipv6: use the right ifindex when replying to icmpv6 from localhostFernando Fernandez Mancera-1/+3
When replying to a ICMPv6 echo request that comes from localhost address the right output ifindex is 1 (lo) and not rt6i_idev dev index. Use the skb device ifindex instead. This fixes pinging to a local address from localhost source address. $ ping6 -I ::1 2001:1:1::2 -c 3 PING 2001:1:1::2 (2001:1:1::2) from ::1 : 56 data bytes 64 bytes from 2001:1:1::2: icmp_seq=1 ttl=64 time=0.037 ms 64 bytes from 2001:1:1::2: icmp_seq=2 ttl=64 time=0.069 ms 64 bytes from 2001:1:1::2: icmp_seq=3 ttl=64 time=0.122 ms 2001:1:1::2 ping statistics 3 packets transmitted, 3 received, 0% packet loss, time 2032ms rtt min/avg/max/mdev = 0.037/0.076/0.122/0.035 ms Fixes: 1b70d792cf67 ("ipv6: Use rt6i_idev index for echo replies to a local address") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20260121194409.6749-1-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
generated by cgit v1.2.3 (git 2.46.0) at 2026-03-21 17:21:25 +0000