{"id":"CVE-2026-31721","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-31721","generatedAt":"2026-10-28T00:25:20.252Z","title":"In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_hid: move list and spinlock inits from bind to alloc There was an issue when you did the following: - setup and bind an hid gadget - open /dev/hidg0 - use the resulting…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_hid: move list and spinlock inits from bind to alloc\n\nThere was an issue when you did the following:\n- setup and bind an hid gadget\n- open /dev/hidg0\n- use the resulting fd in EPOLL_CTL_ADD\n- unbind the UDC\n- bind the UDC\n- use the fd in EPOLL_CTL_DEL\n\nWhen CONFIG_DEBUG_LIST was enabled, a list_del corruption was reported\nwithin remove_wait_queue (via ep_remove_wait_queue). After some\ndebugging I found out that the queues, which f_hid registers via\npoll_wait were the problem. These were initialized using\ninit_waitqueue_head inside hidg_bind. So effectively, the bind function\nre-initialized the queues while there were still items in them.\n\nThe solution is to move the initialization from hidg_bind to hidg_alloc\nto extend their lifetimes to the lifetime of the function instance.\n\nAdditionally, I found many other possibly problematic init calls in the\nbind function, which I moved as well.","published":"2026-05-01T15:16:34.000Z","lastModified":"2026-06-17T10:34:19.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["linux/linux kernel"],"epss":{"score":0.00127,"percentile":0.02368,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.13%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/13440c0db227c5db01da751ed966dde4cdd2ea18","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/26a879a41ed960b3fb4ec773ef2788c515c0e488","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4e0a88254ad59f6c53a34bf5fa241884ec09e8b2","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5d1bb391ceeebb28327703dd07af8c6324af298f","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/81aee4500055876883658b024b6fb61801afe134","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8ec6a58586f195a88479edcdb0b8027c39f12d03","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/de93e0862169b5539e00c2b9980b93fd80c37c0d","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f7d00ee1c8082c8a134340aaf16d71a27e29c362","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31721","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}