CVE-2022-49059

/// Technical description

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

nfc: nci: add flush_workqueue to prevent uaf

Our detector found a concurrent use-after-free bug when detaching an

NCI device. The main reason for this bug is the unexpected scheduling

between the used delayed mechanism (timer and workqueue).

The race can be demonstrated below:

Thread-1 Thread-2

| nci_dev_up()

| nci_open_device()

| __nci_request(nci_reset_req)

| nci_send_cmd

| queue_work(cmd_work)

nci_unregister_device() |

nci_close_device() | ...

del_timer_sync(cmd_timer)[1] |

... | Worker

nci_free_device() | nci_cmd_work()

kfree(ndev)[3] | mod_timer(cmd_timer)[2]

In short, the cleanup routine thought that the cmd_tim

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References