Executive Summary

CVE-2024-41062 is a race condition in the Linux kernel’s Bluetooth L2CAP stack where a socket can be freed by a close operation while a background hci_rx_work thread still accesses it, leading to a use‑after‑free and potential crash or denial of service. The fix adds a mutex to synchronize the socket release with the receive callback and clears channel data on close to prevent invalid pointer usage.

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Authoritative CVE Metadata - CVSS Base Score: 8.8 (HIGH) - Published: 2024-07-29T15:15:14.173 - Last Modified: 2026-10-03T11:17:30.383

Original 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.

"Don't ruin the present with the ruined past."

— Ellen Gilchrist