CVE-2025-40223

most: usb: Fix use-after-free in hdm_disconnect

At a glance

Severity
Not available
EPSS
EPSS 0.21 % · percentile 11 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Deferred

Description

In the Linux kernel, the following vulnerability has been resolved: most: usb: Fix use-after-free in hdm_disconnect hdm_disconnect() calls most_deregister_interface(), which eventually unregisters the MOST interface device with device_unregister(iface->dev). If that drops the last reference, the device core may call release_mdev() immediately while hdm_disconnect() is still executing. The old code also freed several mdev-owned allocations in hdm_disconnect() and then performed additional put_device() calls. Depending on refcount order, this could lead to use-after-free or double-free when release_mdev() ran (or when unregister paths also performed puts). Fix by moving the frees of mdev-owned allocations into release_mdev(), so they happen exactly once when the device is truly released, and by dropping the extra put_device() calls in hdm_disconnect() that are redundant after device_unregister() and most_deregister_interface(). This addresses the KASAN slab-use-after-free reported by syzbot in hdm_disconnect(). See report and stack traces in the bug link below.

European references

CERT-FR advisories

Affected products

ProductVersions
Linux · Linuxaffected 97a6f772f36b7f52bcfa56a581bbd2470cffe23d < 5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831 ; affected 97a6f772f36b7f52bcfa56a581bbd2470cffe23d < 578eb18cd111addec94c43f61cd4b4429e454809 ; affected 97a6f772f36b7f52bcfa56a581bbd2470cffe23d < 33daf469f5294b9d07c4fc98216cace9f4f34cc6 ; affected 97a6f772f36b7f52bcfa56a581bbd2470cffe23d < 72427dc6f87523995f4e6ae35a948bb2992cabce ; affected 97a6f772f36b7f52bcfa56a581bbd2470cffe23d < f93a84ffb884d761a9d4e869ba29c238711e81f1 ; affected 97a6f772f36b7f52bcfa56a581bbd2470cffe23d < 3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6
Linux · Linuxaffected 5.9 ; unaffected 0 < 5.9 ; unaffected 5.10.246 ≤ 5.10.* ; unaffected 5.15.196 ≤ 5.15.* ; unaffected 6.1.158 ≤ 6.1.* ; unaffected 6.6.115 ≤ 6.6.*

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD