Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: mgmt: fix UAF in pair command cancellation
The pairing completion and authentication failure callbacks look up the pending MGMT_OP_PAIR_DEVICE command by walking hdev->mgmt_pending. The lookup returned a command that was still linked on the shared pending list, without keeping mgmt_pending_lock held for the later dereference and removal.
A concurrent MGMT_OP_CANCEL_PAIR_DEVICE request can remove and free the same pending command before the callback uses it. The reverse race is also possible when cancel_pair_device() gets a command from pending_find() and a callback removes it before the cancel path dereferences it. This can lead to a use-after-free and a second list_del().
Make the pairing lookup helpers transfer ownership of the pending command by removing it from hdev->mgmt_pending while holding mgmt_pending_lock. The callbacks and cancel path then complete the command and free it directly, so racing paths cannot find or free the same command again. Take a temporary hci_conn reference in cancel_pair_device() because the command completion drops the reference stored in the pending command.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+4 more)
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |