CVE-2026-90256

Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind

HIGH

8.8

CVSS Score

Published: September 17, 2026 at 04:07 PM UTC

Updated: October 21, 2026 at 01:20 PM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

HIGH8.8

Exploit prediction

EPSS 0.4%

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind hci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via hci_conn_timeout (disc_work) -> hci_proto_disconn_ind -> l2cap_disconn_ind. This is UAF if the l2cap_conn is deleted concurrently. disc_work is disabled sync in hci_conn_del(), so we cannot take hci_dev_lock in disc_work. Fix by using proto_lock to guard l2cap_data, in addition to hdev->lock which is held in other access paths.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

90%

18ab6b6078fa8191ca30a3065d57bf35d56357616.12.20 6.13.8 6.14 6.6.84ab4eedb790cae44313759b50fe47da285e2519d5efc30877bd4bc85fefe98d80af60fafc86e5775ef87271d21dd4ee83857ca11b94e7b4952749bbae

Vendor states this is fixed in 2b66c83ff1751d6bd3201b3017206262ab46dc05 (fixed)

Vendor states this is fixed in b495a3a9b33bc4e4613e685bf5c96c136caa22d8 (fixed)

Vendor states this is fixed in 6.12.114 (unaffected)

Affected range stops below 6.13, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 6.14 (unaffected)

Vendor states this is fixed in 6.6.160 (unaffected)

Affected range stops below 6.7, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 7.2.6 (unaffected)

Vendor states this is fixed in 7.3 (unaffected)

Vendor states this is fixed in 7.3-rc1 (unaffected)