CVE-2026-64331
In the Linux kernel, the following vulnerability has been resolved: usbip: vudc: fix NULL deref in vep_dequeue() vep_alloc_request() wasn't initializing vrequest->udc, so cancellations on the FunctionFS AIO path were arriving in vep_dequeue without a valid UDC reference. Since vrequest->udc is never actually properly used anywhere, we opt to remove it, and update vep_dequeue to obtain a reference to the udc with ep_to_vudc(), consistent with the other vep_ ops. AFAICT this bug has existed for ~10 years. Seems that nobody has really stressed the FunctionFS AIO path on usbip's vudc. I tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints via AIO. Before the fix, running `usbip attach` from the host would cause the guest to oops with the following backtrace: Call trace: vep_dequeue+0x1c/0xe4 (P) usb_ep_dequeue+0x14/0x20 ffs_aio_cancel+0x24/0x34 __arm64_sys_io_cancel+0xb0/0x124 do_el0_svc+0x68/0x100 el0_svc+0x18/0x5c el0t_64_sync_handler+0x98/0xdc el0t_64_sync+0x154/0x158
Affected versions
Linux kernel versions
4.7
and later are affected. Fixed in
5.10.261,
5.15.212,
6.1.178,
6.6.145,
6.12.96,
6.18.39,
7.1.4,
7.2-rc3
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-64331?
CVE-2026-64331 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.7 onward and has been patched in 5.10.261, 5.15.212, 6.1.178 and others. CVE-2026-64331 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-64331?
Yes. CVE-2026-64331 has been patched. Fixed versions include 5.10.261, 5.15.212, 6.1.178 and others. If you are running Linux kernel 4.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-64331 actively exploited?
No. CVE-2026-64331 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.