CVE-2026-74533

Summary

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero

hci_conn::iso_data is accessed and modified without lock or RCU. This leads to a race

[Task hdev->workqueue]                 	[Task 2]
iso_recv                                    iso_conn_put(conn)
  conn = LOAD hcon->iso_data                  iso_conn_free(conn)
  iso_conn_hold_unless_zero(conn)               hcon->iso_data = NULL
                                                kfree(conn)
    kref_get_unless_zero(&conn->ref) /* UAF */

and also to races in iso_conn_add() vs. iso_conn_free().

Fix by adding spinlock hci_conn::proto_lock and using it to guard hci_conn::iso_data.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxdc26097bdb864a0d5955b9a25e43376ffc1af99b < 876a3e94c70d0859d1dad1c986112d4f0d99eba8affected
LinuxLinuxdc26097bdb864a0d5955b9a25e43376ffc1af99b < af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9caffected
LinuxLinuxf53e7489273dc2bb307bf50f319b3762d45534f0affected
LinuxLinuxa58d0f5dac322e16cc75334d000666512341bde5affected
LinuxLinux6.11.11 < 6.12affected
LinuxLinux6.12.2 < 6.13affected
LinuxLinux6.13affected
LinuxLinux0 < 6.13unaffected
LinuxLinux7.1.8 <= 7.1.*unaffected
LinuxLinux7.2-rc6 <= *unaffected

Weaknesses

References