CVE-2026-74540

Summary

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

Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp

l2cap_le_connect_rsp() obtains a channel via __l2cap_get_chan_by_ident() but neither holds a reference nor uses l2cap_chan_hold_unless_zero() before locking and operating on it. A concurrent l2cap_chan_del() triggered by a remote disconnect can free the channel between the lookup and l2cap_chan_lock(), causing a use-after-free.

The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero() to safely hold a reference, but l2cap_le_connect_rsp() was left unprotected.

Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup and l2cap_chan_put() on the exit path, consistent with other L2CAP response handlers.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxf1496dee9cbde2a62821f4441dadb0d3360f60c3 < fd4c1e301bdec60a40728ea37de531cbccda501aaffected
LinuxLinuxf1496dee9cbde2a62821f4441dadb0d3360f60c3 < 522b730c62c53a1981604fd73524697fd347830daffected
LinuxLinuxf1496dee9cbde2a62821f4441dadb0d3360f60c3 < 58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136affected
LinuxLinuxf1496dee9cbde2a62821f4441dadb0d3360f60c3 < 09f447accc2570751e7d17f0dc0788b40d3edadeaffected
LinuxLinuxf1496dee9cbde2a62821f4441dadb0d3360f60c3 < c4740e7f23ff9a8210198d8b4703259e21b9f69daffected
LinuxLinux3.14affected
LinuxLinux0 < 3.14unaffected
LinuxLinux6.6.151 <= 6.6.*unaffected
LinuxLinux6.12.103 <= 6.12.*unaffected
LinuxLinux6.18.44 <= 6.18.*unaffected
LinuxLinux7.1.8 <= 7.1.*unaffected
LinuxLinux7.2-rc6 <= *unaffected

Weaknesses

References