CVE-2024-41062: bluetooth/l2cap: sync sock recv cb and release

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-29 · updated 2026-10-03

Description

In the Linux kernel, the following vulnerability has been resolved: bluetooth/l2cap: sync sock recv cb and release The problem occurs between the system call to close the sock and hci_rx_work, where the former releases the sock and the latter accesses it without lock protection. CPU0 CPU1 ---- ---- sock_close hci_rx_work l2cap_sock_release hci_acldata_packet l2cap_sock_kill l2cap_recv_frame sk_free l2cap_conless_channel l2cap_sock_recv_cb If hci_rx_work processes the data that needs to be received before the sock is closed, then everything is normal; Otherwise, the work thread may access the released sock when receiving data. Add a chan mutex in the rx callback of the sock to achieve synchronization between the sock release and recv cb. Sock is dead, so set chan data to NULL, avoid others use invalid sock pointer.

Affected products

Linux kernel: before 6.1.101; from 6.2 before 6.6.42; from 6.7 before 6.9.11; 6.10-rc1, 6.10-rc2, 6.10-rc3, 6.10-rc4, 6.10-rc5, 6.10-rc6 — fixed in 6.1.101, 6.6.42, 6.9.11

How to fix

Upgrade to a fixed version: Linux kernel 6.1.101, 6.6.42, 6.9.11. Check the vendor advisory for mitigations.

References

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