{"id":"CVE-2026-68372","summary":"usb: core: port: Deattach Type-C connector on component unbind","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: core: port: Deattach Type-C connector on component unbind\n\nconnector_unbind() is the mirror of connector_bind(), but it is missing\nthe symmetric call to typec_deattach() that connector_bind() makes via:\n\n    if (port_dev-\u003echild)\n        typec_attach(port_dev-\u003econnector, &port_dev-\u003echild-\u003edev);\n\nWhen a Thunderbolt dock is unplugged, two teardown paths race:\n\n1. The component framework calls connector_unbind() first, which sets\n   port_dev-\u003econnector = NULL without calling typec_deattach().  This\n   leaves port-\u003eusb2_dev/port-\u003eusb3_dev in struct typec_port pointing at\n   the USB device that is about to be freed.\n\n2. usb_disconnect() then calls typec_deattach(port_dev-\u003econnector, ...),\n   but port_dev-\u003econnector is already NULL, so the call is a no-op and\n   port-\u003eusb2_dev is never cleared.\n\n3. Concurrently, UCSI detects a PD partner-disconnect event and calls\n   typec_unregister_partner(), which reads port-\u003eusb2_dev (now a dangling\n   pointer to freed memory) and passes it to typec_partner_unlink_device()\n   -\u003e sysfs_remove_link() -\u003e dev_name() on the freed device, corrupting\n   the typec/UCSI partner state.\n\nThis corruption leaves the Thunderbolt tunnel in an inconsistent state on\nthe next dock hot-plug.  On affected hardware the dock's I225/igc NIC fails\nto enumerate: AER fires a slot reset while the igc driver is still\ninitialising (\"PCIe link lost\"), and the subsequent igc_reset attempt hits\nigc_rd32 on an already-detached device:\n\n    igc 0000:2e:00.0 eth0: PCIe link lost, device now detached\n    igc: Failed to read reg 0x0!\n    WARNING: CPU: 9 PID: 129 at drivers/net/ethernet/intel/igc/igc_main.c:7005\n             igc_rd32+0xa4/0xc0 [igc]\n    Call Trace:\n     igc_disable_pcie_master+0x16/0xa0 [igc]\n     igc_reset_hw_base+0x14/0x170 [igc]\n     igc_reset+0x63/0x110 [igc]\n     igc_io_slot_reset+0x9e/0xd0 [igc]\n     report_slot_reset+0x5d/0xc0\n     pcie_do_recovery+0x209/0x400\n     aer_isr_one_error_type+0x235/0x430\n     aer_isr+0x4e/0x80\n     irq_thread+0xf4/0x1f0\n\n4. UCSI later handles the PD partner-disconnect and calls\n   typec_unregister_partner(), which still sees the stale port-\u003eusb2_dev\n   and tries to remove its sysfs link a second time:\n\n   kernfs: can not remove 'typec', no directory\n   WARNING: CPU: 6 PID: 55 at fs/kernfs/dir.c:1706 kernfs_remove_by_name_ns+0xe9/0xf0\n   Workqueue: events ucsi_handle_connector_change [typec_ucsi]\n   Call Trace:\n    sysfs_remove_link+0x19/0x50\n    typec_unregister_partner+0x6e/0x120 [typec]\n    ucsi_unregister_partner+0x107/0x150 [typec_ucsi]\n    ucsi_handle_connector_change+0x3ec/0x490 [typec_ucsi]\n    process_one_work+0x18e/0x3e0\n    worker_thread+0x2e3/0x420\n    kthread+0x10a/0x230\n    ret_from_fork+0x121/0x140\n    ret_from_fork_asm+0x1a/0x30\n\n   With worse timing the same stale pointer is dereferenced after the\n   backing memory is freed, turning the warning into a use-after-free.\n\nFix the asymmetry: call typec_deattach() before clearing\nport_dev-\u003econnector, matching what connector_bind() does on the bind side.\ntypec_partner_deattach() is already protected by port-\u003epartner_link_lock,\nso it serialises safely with the concurrent typec_unregister_partner() path.","modified":"2026-08-12T04:18:48.310339788Z","published":"2026-08-10T12:03:50.292Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68372.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/7714fb896ed308cf13d32d317040adc4f200b8e4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/78d361e60caf1999d51bda0e1b1004f5d39fcfbc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e00109b5adf71635919248e9ab6300a662e6a3e8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e0b291fe117964037e0ba382eff4bb365d531c3a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68372.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68372"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"11110783f5ea866318831a56353c6f1c3fc0d8ed"},{"fixed":"78d361e60caf1999d51bda0e1b1004f5d39fcfbc"},{"fixed":"7714fb896ed308cf13d32d317040adc4f200b8e4"},{"fixed":"e00109b5adf71635919248e9ab6300a662e6a3e8"},{"fixed":"e0b291fe117964037e0ba382eff4bb365d531c3a"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68372.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68372.json"}}],"schema_version":"1.9.0"}