CVE-2024-46691

/// Technical description

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

usb: typec: ucsi: Move unregister out of atomic section

Commit '9329933699b3 ("soc: qcom: pmic_glink: Make client-lock

non-sleeping")' moved the pmic_glink client list under a spinlock, as it

is accessed by the rpmsg/glink callback, which in turn is invoked from

IRQ context.

This means that ucsi_unregister() is now called from atomic context,

which isn't feasible as it's expecting a sleepable context. An effort is

under way to get GLINK to invoke its callbacks in a sleepable context,

but until then lets schedule the unregistration.

A side effect of this is that ucsi_unregister() can now happen

after the remote processor, and thereby the communication link with it, is

gone. pmic_glink_send() is amended with a check to avoid the resulting NULL

pointer dereference.

This does however result in the user being informed about this error by

the following entry in the kernel log:

ucsi_glink.pmic_glink_ucsi pmic_glink.ucs

/// 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