{"cve":"CVE-2026-64331","nvd":{"published":"2026-07-25T10:17:14.813","modified":"2026-09-03T16:04:40.863","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: vudc: fix NULL deref in vep_dequeue()\n\nvep_alloc_request() wasn't initializing vrequest->udc, so cancellations\non the FunctionFS AIO path were arriving in vep_dequeue without a valid\nUDC reference.\n\nSince vrequest->udc is never actually properly used anywhere, we opt to\nremove it, and update vep_dequeue to obtain a reference to the udc with\nep_to_vudc(), consistent with the other vep_ ops.\n\nAFAICT this bug has existed for ~10 years. Seems that nobody has really\nstressed the FunctionFS AIO path on usbip's vudc.\n\nI tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints\nvia AIO. Before the fix, running `usbip attach` from the host would\ncause the guest to oops with the following backtrace:\n\nCall trace:\n vep_dequeue+0x1c/0xe4 (P)\n usb_ep_dequeue+0x14/0x20\n ffs_aio_cancel+0x24/0x34\n __arm64_sys_io_cancel+0xb0/0x124\n do_el0_svc+0x68/0x100\n el0_svc+0x18/0x5c\n el0t_64_sync_handler+0x98/0xdc\n el0t_64_sync+0x154/0x158","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9","https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e","https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652","https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f","https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:46:40.600842820+00:00"},"epss":{"cve":"CVE-2026-64331","score":0.00123,"percentile":0.02015,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}