CVE-2025-40223 | most: usb: Fix use-after-free in hdm_disconnect

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.

Published: 2025-12-04 Last update: 2026-04-15 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-40223 is rated Low Risk (18.1/100): low exploitation likelihood (EPSS 0.06%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-40223

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-14 0.04% 0.06% +0.01%
2 2026-05-02 0.06% 0.04% -0.01%
3 2025-12-18 0.06%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-40223

CVSS metrics for this CVE.

No CVSS data in dataset for this CVE.

Weakness enumeration for CVE-2025-40223

OS Trackers for CVE-2025-40223

vendor priority summary link
debian not yet assigned CVE-2025-40223 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-40223
redhat https://access.redhat.com/security/cve/CVE-2025-40223
suse medium CVE-2025-40223 severity moderate: SUSE including 471 source package names (13.2-9.1:libsystemd0-254.23-1.1, 13.2-9.1:libudev1-254.23-1.1, …), 1013 product×package rows across 183 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (183 product lines)): Fixed 643, Known Affected 231, Known Not Affected 114, First Fixed 25. https://www.suse.com/security/cve/CVE-2025-40223/
ubuntu medium CVE-2025-40223 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1405 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1010, ignored 178, released 157, not-affected 49, needed 8, pending 3. https://ubuntu.com/security/CVE-2025-40223

Affected software / configurations for CVE-2025-40223

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-40223

cvelogic Threat Intelligence