{"id":"CVE-2026-74677","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: ipheth: fix carrier_work UAF on disconnect\n\nipheth_sndbulk_callback() re-arms the carrier-check work on any\nnon-zero URB status:\n\n\telse\n\t\tschedule_delayed_wor…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: ipheth: fix carrier_work UAF on disconnect\n\nipheth_sndbulk_callback() re-arms the carrier-check work on any\nnon-zero URB status:\n\n\telse\n\t\tschedule_delayed_wor…","severity":"medium","published":"2026-08-22","updated":"2026-10-14","sourceUpdated":"2026-10-14T13:10:00.187","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74677","references":[{"url":"https://git.kernel.org/stable/c/2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/48303f3ae0fa6e102f3fc7dbf1688cc179131962","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d07133fe1befae9a1e4c4c5e46ef0b73d2992020","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fde39b8a521780391fb4e5bda2c0aa4928947f12","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74677.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-74677"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2521362"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74677"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74677"},{"url":"https://kernelcve.org/list/?q=CVE-2026-74677"},{"url":"https://lore.kernel.org/linux-cve-announce/2026082231-CVE-2026-74677-ecca@gregkh/T"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00168,"epssPercentile":0.06056,"ingestedAt":"2026-10-14T13:30:58.534Z","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 7","enterprise_linux 8","enterprise_linux 9"],"cvss":4.7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-416"],"slug":"CVE-2026-74677","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: ipheth: fix carrier_work UAF on disconnect\n\nipheth_sndbulk_callback() re-arms the carrier-check work on any\nnon-zero URB status:\n\n\telse\n\t\tschedule_delayed_work(&dev->carrier_work, 0);\n\nNothing ties that to the interface being up, so the work can be armed\nagain after ipheth_close() has already drained it, and stay armed\nuntil the netdev whose private area embeds it is freed.\n\nOn unplug with a TX URB in flight, ipheth_disconnect() drains the work\nthrough unregister_netdev() -> ipheth_close() ->\ncancel_delayed_work_sync() and only then calls ipheth_kill_urbs().\nusb_kill_urb() completes the in-flight TX URB with -ENOENT, so\nipheth_sndbulk_callback() runs after the drain and re-arms\ncarrier_work.\n\nThe same completion also re-arms the work if the interface is only\nbrought down while a TX URB is in flight, and\nipheth_carrier_check_work() then keeps re-queueing itself once a\nsecond. unregister_netdev() does not call ipheth_close() for an\nalready-down interface, so nothing drains it on the later unplug\neither.\n\nIn both cases free_netdev() frees the netdev while carrier_work is\nstill pending, and ipheth_carrier_check_work() dereferences freed\nmemory.\n\nTie the work to the interface state instead of chasing the completion:\ndisable it in ipheth_close() and enable it in ipheth_open(), so a\nschedule_delayed_work() from the URB completion is a no-op whenever\nthe interface is not up. disable_delayed_work_sync() also waits for a\nrunning instance, so it fully replaces the cancel_delayed_work_sync()\nit takes the place of. The work starts out disabled in ipheth_probe()\nso the enable/disable counts balance from the first open.\n\nReproduced under KASAN on linux-next (next-20260731) with dummy_hcd and\nraw-gadget standing in for the device, driving the second path above (the\ninterface is already down, so unregister_netdev() does not call\nipheth_close()): 15 of 15 unpatched boots report a slab-use-after-free in\n__run_timers(), freed by ipheth_disconnect() and re-armed from\nipheth_sndbulk_callback() via queue_delayed_work_on(). The\nsame trigger on a kernel differing only by this patch reports 0 of 15,\nand the carrier check still functions across open/close cycles.\n\nThe reproducer needs an attached USB device that stops draining bulk OUT,\nplus a link down and unplug, driven as root. It is not a privilege\nboundary crossing and no exploit primitive was developed.\n\nFound by 0sec (https://0sec.ai).\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74677.json)","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":229428,"id":"CVE-2026-74677","ts":1793019761114,"field":"cvss","old":null,"new":"4.7"},{"seq":229427,"id":"CVE-2026-74677","ts":1793019761114,"field":"severity","old":"none","new":"medium"}]}