CVE-2026-64331

usbip: vudc: fix NULL deref in vep_dequeue()

State: Published
Severity: Not scored
Published: Jul 25, 2026
Updated: Aug 17, 2026
Reserved: Jul 19, 2026

Description

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

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	b6a0ca11186759ad7045d68a5447b1e89f658384 to before 9858c91d9ee6a13c45311569039413729fc9b757Affected b6a0ca11186759ad7045d68a5447b1e89f658384 to before 1226293ec9bed3d4cc5b05eeeb811d315ca51652Affected b6a0ca11186759ad7045d68a5447b1e89f658384 to before 3750f75f29f99c0223601e2ee73ad084adec47bdAffected b6a0ca11186759ad7045d68a5447b1e89f658384 to before d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97Affected b6a0ca11186759ad7045d68a5447b1e89f658384 to before 0025276175fbbe0dcbf3f84d090b0adee769e9d9Affected b6a0ca11186759ad7045d68a5447b1e89f658384 to before 347b59e9f96719d89b6ef555d02a18ada1a5846fAffected b6a0ca11186759ad7045d68a5447b1e89f658384 to before 0443e4416aa1ee97748d1ed904eaf3352c60045eAffected b6a0ca11186759ad7045d68a5447b1e89f658384 to before c5371e0b91b24159a3ebaa61e70b0980bcf03c0aAffected
LinuxLinux	4.7Affected before 4.7Not affected 5.10.261 through 5.10.Not affected 5.15.212 through 5.15.Not affected 6.1.178 through 6.1.Not affected 6.6.145 through 6.6.Not affected 6.12.96 through 6.12.Not affected 6.18.39 through 6.18.Not affected 7.1.4 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

b6a0ca11186759ad7045d68a5447b1e89f658384 to before 9858c91d9ee6a13c45311569039413729fc9b757Affected
b6a0ca11186759ad7045d68a5447b1e89f658384 to before 1226293ec9bed3d4cc5b05eeeb811d315ca51652Affected
b6a0ca11186759ad7045d68a5447b1e89f658384 to before 3750f75f29f99c0223601e2ee73ad084adec47bdAffected
b6a0ca11186759ad7045d68a5447b1e89f658384 to before d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97Affected
b6a0ca11186759ad7045d68a5447b1e89f658384 to before 0025276175fbbe0dcbf3f84d090b0adee769e9d9Affected
b6a0ca11186759ad7045d68a5447b1e89f658384 to before 347b59e9f96719d89b6ef555d02a18ada1a5846fAffected
b6a0ca11186759ad7045d68a5447b1e89f658384 to before 0443e4416aa1ee97748d1ed904eaf3352c60045eAffected
b6a0ca11186759ad7045d68a5447b1e89f658384 to before c5371e0b91b24159a3ebaa61e70b0980bcf03c0aAffected

LinuxLinux

4.7Affected
before 4.7Not affected
5.10.261 through 5.10.*Not affected
5.15.212 through 5.15.*Not affected
6.1.178 through 6.1.*Not affected
6.6.145 through 6.6.*Not affected
6.12.96 through 6.12.*Not affected
6.18.39 through 6.18.*Not affected
7.1.4 through 7.1.*Not affected
7.2 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.