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{ "id": 2225524, "url": "http://patchwork.ozlabs.org/api/covers/2225524/?format=api", "web_url": "http://patchwork.ozlabs.org/project/ubuntu-kernel/cover/20260421062928.2968600-1-gerald.yang@canonical.com/", "project": { "id": 15, "url": "http://patchwork.ozlabs.org/api/projects/15/?format=api", "name": "Ubuntu Kernel", "link_name": "ubuntu-kernel", "list_id": "kernel-team.lists.ubuntu.com", "list_email": "kernel-team@lists.ubuntu.com", "web_url": null, "scm_url": null, "webscm_url": null, "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260421062928.2968600-1-gerald.yang@canonical.com>", "list_archive_url": null, "date": "2026-04-21T06:29:21", "name": "[SRU,N,0/1] Revert \"netfilter: conntrack: fix erronous removal of offload bit\"", "submitter": { "id": 77781, "url": "http://patchwork.ozlabs.org/api/people/77781/?format=api", "name": "Gerald Yang", "email": "gerald.yang@canonical.com" }, "mbox": "http://patchwork.ozlabs.org/project/ubuntu-kernel/cover/20260421062928.2968600-1-gerald.yang@canonical.com/mbox/", "series": [ { "id": 500743, "url": "http://patchwork.ozlabs.org/api/series/500743/?format=api", "web_url": "http://patchwork.ozlabs.org/project/ubuntu-kernel/list/?series=500743", "date": "2026-04-21T06:29:21", "name": "Revert \"netfilter: conntrack: fix erronous removal of offload bit\"", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/500743/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2225524/comments/", "headers": { "Return-Path": "<kernel-team-bounces@lists.ubuntu.com>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=fail reason=\"signature verification failed\" (4096-bit key;\n unprotected) header.d=canonical.com header.i=@canonical.com\n header.a=rsa-sha256 header.s=20251003 header.b=XQ/qzRy1;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com\n (client-ip=185.125.189.65; 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charset=\"utf-8\"", "Content-Transfer-Encoding": "base64", "Errors-To": "kernel-team-bounces@lists.ubuntu.com", "Sender": "\"kernel-team\" <kernel-team-bounces@lists.ubuntu.com>" }, "content": "BugLink: https://bugs.launchpad.net/bugs/2149762\n\n[Impact]\n\nWith this commit:\nnetfilter: conntrack: fix erronous removal of offload bit\n\nWe hit the regression on PS6/7, all the nodes with this commit hit soft lockup every 1-2 days and need to reboot the nodes to recover, e.g.:\n\n[1022567.831263] watchdog: BUG: soft lockup - CPU#352 stuck for 26s! [kworker/u789:13:1036823]\n[1022567.831271] Modules linked in: scsi_transport_iscsi mlx5_vfio_pci vfio_pci_core vfio_iommu_type1 vfio iommufd vhost_net tap xfs act_csum act_pedit act_ct nf_flow_table act_tunnel_key xt_CT xt_tcpudp nft_compat dm_crypt ebtable_filter ebtables ip6table_raw ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_raw iptable_mangle iptable_nat iptable_filter nf_tables veth nf_conntrack_netlink vhost_vsock vmw_vsock_virtio_transport_common vhost vsock nvme_fabrics nvme_keyring act_mirred act_skbedit act_vlan cls_matchall 8021q garp mrp geneve ip6_udp_tunnel udp_tunnel nfnetlink_cttimeout nfnetlink act_gact cls_flower sch_ingress openvswitch nsh nf_conncount nf_nat bridge stp llc bonding sunrpc binfmt_misc intel_rapl_msr intel_rapl_common amd64_edac edac_mce_amd kvm_amd kvm irqbypass rapl ipmi_ssif nls_iso8859_1 joydev input_leds ipmi_si ipmi_devintf k10temp ccp ipmi_msghandler mac_hid mlx5_vdpa vringh vhost_iotlb vdpa dm_service_time sch_fq_codel dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua nf_conntrack\n[1022567.831352] nf_defrag_ipv6 nf_defrag_ipv4 efi_pstore ip_tables x_tables autofs4 btrfs blake2b_generic raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 mlx5_ib ib_uverbs macsec ib_core raid10 hid_generic usbhid ses hid enclosure dax_hmem mlx5_core crct10dif_pclmul crc32_pclmul cxl_acpi polyval_clmulni cxl_port mlxfw polyval_generic ghash_clmulni_intel sha256_ssse3 sha1_ssse3 cxl_core psample nvme mpt3sas ahci raid_class nvme_core tls ast tg3 scsi_transport_sas libahci pci_hyperv_intf nvme_auth i2c_algo_bit xhci_pci xhci_pci_renesas i2c_piix4 aesni_intel crypto_simd cryptd\n[1022567.831407] CPU: 352 PID: 1036823 Comm: kworker/u789:13 Kdump: loaded Tainted: G L 6.8.0-106-generic #106~22.04.1+hf399032v20260316b0-Ubuntu\n[1022567.831411] Hardware name: Lenovo ThinkSystem SR665 V3/SB27B75430, BIOS KAE140F-5.70 09/03/2025\n[1022567.831413] Workqueue: events_power_efficient nf_flow_offload_work_gc [nf_flow_table]\n[1022567.831425] RIP: 0010:rhashtable_walk_next+0x17/0xd0\n[1022567.831433] Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 4c 8b 37 48 89 fb 4c 8b 7f 10 <4c> 8b 6f 08 45 0f b6 66 38 41 80 fc 01 0f 87 e4 b1 98 00 41 83 e4\n[1022567.831435] RSP: 0018:ff732ea21e2cbda8 EFLAGS: 00000202\n[1022567.831438] RAX: ff2b1e3b98ea4058 RBX: ff732ea21e2cbde0 RCX: 0000000000000000\n[1022567.831440] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff732ea21e2cbde0\n[1022567.831441] RBP: ff732ea21e2cbdd0 R08: 0000000000000000 R09: 0000000000000000\n[1022567.831442] R10: 0000000000000000 R11: 0000000000000000 R12: ff2b1cb8611cbee8\n[1022567.831444] R13: ff2b1cb8611cbe40 R14: ff2b1cb8611cbe48 R15: ff2b1e3b98ea4058\n[1022567.831445] FS: 0000000000000000(0000) GS:ff2b1fb3bb000000(0000) knlGS:0000000000000000\n[1022567.831447] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[1022567.831449] CR2: 0000775a42eee000 CR3: 0000019530ce8003 CR4: 0000000000f71ef0\n[1022567.831450] PKRU: 55555554\n[1022567.831452] Call Trace:\n[1022567.831454] <TASK>\n[1022567.831461] nf_flow_offload_work_gc+0x5a/0xf0 [nf_flow_table]\n[1022567.831468] process_one_work+0x181/0x3a0\n[1022567.831475] worker_thread+0x306/0x440\n[1022567.831479] ? __pfx_worker_thread+0x10/0x10\n[1022567.831481] kthread+0xef/0x120\n[1022567.831485] ? __pfx_kthread+0x10/0x10\n[1022567.831487] ret_from_fork+0x44/0x70\n[1022567.831492] ? __pfx_kthread+0x10/0x10\n[1022567.831494] ret_from_fork_asm+0x1b/0x30\n[1022567.831502] </TASK>\n[1022568.208115] R13: 0000000000000002 R14: 0000000000000002 R15: 0003a1fef9c1d979\n[1022568.216666] ? cpuidle_enter_state+0xca/0x720\n[1022568.222092] ? tick_nohz_stop_tick+0x70/0x210\n[1022568.227521] cpuidle_enter+0x2e/0x50\n[1022568.232060] call_cpuidle+0x23/0x60\n[1022568.236472] cpuidle_idle_call+0x11d/0x190\n[1022568.241562] do_idle+0x87/0xf0\n[1022568.245472] cpu_startup_entry+0x2a/0x30\n[1022568.250357] start_secondary+0x129/0x160\n[1022568.255243] secondary_startup_64_no_verify+0x184/0x18b\n[1022568.261586] </TASK>\n\n[Fix]\n\nWithout this commit, we spent few weeks to confirm PS6/7 nodes running without any lockup.\nThis commit is a follow-up fix for:\nnetfilter: conntrack: rework offload nf_conn timeout extension logic\n\nBut the call path and logic starting from flow_offload_fixup_ct changed between these 2 commits.\nOnly manually backport this commit without all the changes in the middle causes issue, and the commit message also says what it fixes is harmless.\n\n[Test Plan]\n\nWe have run a test kernel without this commit on PS6/7 for almost 2 weeks without hitting any soft lockup.\n\n[Where problems could occur]\n\nThe commit we revert, its commit message says what it fixes is harmless,\nand we have already run the kernel without it for almost 2 weeks without any issue, the risk is very low.\n\nGerald Yang (1):\n Revert \"netfilter: conntrack: fix erronous removal of offload bit\"\n\n net/netfilter/nf_flow_table_core.c | 10 ++++------\n 1 file changed, 4 insertions(+), 6 deletions(-)" }