Medium 5.5Published Jul 25, 2026

CVE-2026-64331usbip: vudc: fix NULL deref in vep_dequeue()

Updated under an hour ago (Oct 27, 2026, 9:20 AM ET)

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Exploited in the last 30 days

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

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Aug 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from b6a0ca11186759ad7045d68a5447b1e89f658384 before 9858c91d9ee6a13c45311569039413729fc9b757; from b6a0ca11186759ad7045d68a5447b1e89f658384 before 1226293ec9bed3d4cc5b05eeeb811d315ca51652; from b6a0ca11186759ad7045d68a5447b1e89f658384 before 3750f75f29f99c0223601e2ee73ad084adec47bd; from b6a0ca11186759ad7045d68a5447b1e89f658384 before d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97; from b6a0ca11186759ad7045d68a5447b1e89f658384 before 0025276175fbbe0dcbf3f84d090b0adee769e9d9; from b6a0ca11186759ad7045d68a5447b1e89f658384 before 347b59e9f96719d89b6ef555d02a18ada1a5846f; from b6a0ca11186759ad7045d68a5447b1e89f658384 before 0443e4416aa1ee97748d1ed904eaf3352c60045e; from b6a0ca11186759ad7045d68a5447b1e89f658384 before c5371e0b91b24159a3ebaa61e70b0980bcf03c0a	CNA record
linux linux_kernel linux:linux_kernel	from 4.7 before 5.10.261; from 5.11 before 5.15.212; from 5.16 before 6.1.178; from 6.2 before 6.6.145; from 6.7 before 6.12.96; from 6.13 before 6.18.39; from 6.19 before 7.1.4; 7.2; and 1 more ranges	NVD

References

References

https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757	patch
https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652	patch
https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd	patch
https://git.kernel.org/stable/c/d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97	patch
https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9	patch
https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f	patch
https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e	patch
https://git.kernel.org/stable/c/c5371e0b91b24159a3ebaa61e70b0980bcf03c0a	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.