Bluetooth: hci_sync: fix UAF in hci_le_create_cis_sync (Linux Linux)

CVE-2026-63944
HIGH 8.8

At a glance

Source
NVD
EPSS
EPSS 0.33 % · percentile 27 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix UAF in hci_le_create_cis_sync hci_le_create_cis_sync() dereferences conn->conn_timeout after releasing both rcu_read_lock() and hci_dev_lock(hdev). The conn pointer was obtained from an RCU-protected iteration over hdev->conn_hash.list and is not valid once these locks are dropped. A concurrent disconnect can free the hci_conn between the unlock and the dereference, causing a use-after-free read. The cancellation mechanism in hci_conn_del() cannot prevent this because hci_le_create_cis_pending() queues hci_create_cis_sync with data=NULL: hci_cmd_sync_queue(hdev, hci_create_cis_sync, NULL, NULL); While hci_conn_del() dequeues with data=conn: hci_cmd_sync_dequeue(hdev, NULL, conn, NULL); Since NULL != conn, the lookup in _hci_cmd_sync_lookup_entry() never matches, and the pending work item is not cancelled. Fix this by saving conn->conn_timeout into a local variable while the locks are still held, so the stale conn pointer is never dereferenced after unlock. This is the same class of bug as the one fixed by commit 035c25007c9e ("Bluetooth: hci_sync: Fix UAF on le_read_features_complete") which addressed the identical pattern in a different function. This vulnerability was identified using 0sec.ai, an open-source automated security auditing platform (https://github.com/0sec-labs).

Weaknesses (CWE)

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 8.8CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1HIGH 8.8CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected c09b80be6ffc338634b2f5f8cfa12b6843410834 < a55618c0f4cead9e59c63f5ee030d393fd70d861 ; affected c09b80be6ffc338634b2f5f8cfa12b6843410834 < a921957d39290143629eb38c4f74b9bef8035d0a ; affected c09b80be6ffc338634b2f5f8cfa12b6843410834 < d9019210c8c30d40eb20094274cc647e352f48f7 ; affected c09b80be6ffc338634b2f5f8cfa12b6843410834 < 380e67b1794a9a281a0cb592b4e62077fbd0c8ca ; affected c09b80be6ffc338634b2f5f8cfa12b6843410834 < bfea6091e0fffb270c20e74384b660910277eb6c
Linux · Linuxaffected 6.4 ; unaffected 0 < 6.4 ; unaffected 6.6.143 ≤ 6.6.* ; unaffected 6.12.93 ≤ 6.12.* ; unaffected 6.18.35 ≤ 6.18.* ; unaffected 7.0.12 ≤ 7.0.*

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