usb: gadget: u_ether: Fix race between gether_disconnect and eth_stop (Linux Linux)

CVE-2026-31728
MEDIUM 4.7

At a glance

Source
NVD
EPSS
EPSS 0.09 % · percentile 0 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_ether: Fix race between gether_disconnect and eth_stop A race condition between gether_disconnect() and eth_stop() leads to a NULL pointer dereference. Specifically, if eth_stop() is triggered concurrently while gether_disconnect() is tearing down the endpoints, eth_stop() attempts to access the cleared endpoint descriptor, causing the following NPE: Unable to handle kernel NULL pointer dereference Call trace: __dwc3_gadget_ep_enable+0x60/0x788 dwc3_gadget_ep_enable+0x70/0xe4 usb_ep_enable+0x60/0x15c eth_stop+0xb8/0x108 Because eth_stop() crashes while holding the dev->lock, the thread running gether_disconnect() fails to acquire the same lock and spins forever, resulting in a hardlockup: Core - Debugging Information for Hardlockup core(7) Call trace: queued_spin_lock_slowpath+0x94/0x488 _raw_spin_lock+0x64/0x6c gether_disconnect+0x19c/0x1e8 ncm_set_alt+0x68/0x1a0 composite_setup+0x6a0/0xc50 The root cause is that the clearing of dev->port_usb in gether_disconnect() is delayed until the end of the function. Move the clearing of dev->port_usb to the very beginning of gether_disconnect() while holding dev->lock. This cuts off the link immediately, ensuring eth_stop() will see dev->port_usb as NULL and safely bail out.

Weaknesses (CWE)

  • CWE-362 — Concurrent Execution using Shared Resource with Improper Synchronization

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 2b3d942c4878084a37991a65e66512c02b8fa2ad < f02980594deef751e42133714aee25228f1494c6 ; affected 2b3d942c4878084a37991a65e66512c02b8fa2ad < e1e7a66584bf0aff3becb73c19fa31527889fc9e ; affected 2b3d942c4878084a37991a65e66512c02b8fa2ad < a259ba0bce3b192c04334499690372a250f7d0b1 ; affected 2b3d942c4878084a37991a65e66512c02b8fa2ad < f6813c2b2ae78def76b69e0f9d72f80e4a1c4aca ; affected 2b3d942c4878084a37991a65e66512c02b8fa2ad < bbb09bb89ffa571475f66daca9482b974cd29d6a ; affected 2b3d942c4878084a37991a65e66512c02b8fa2ad < 6ad77458637b78ec655e3da5f112c862e6690a9d
Linux · Linuxaffected 2.6.27 ; unaffected 0 < 2.6.27 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.169 ≤ 6.1.* ; unaffected 6.6.134 ≤ 6.6.*

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