CVE-2024-46693 soc: qcom: pmic_glink: Fix race during initialization
A race condition in the Qualcomm PMIC GLINK driver causes a NULL pointer dereference, leading to a kernel crash during initialization.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-46693?
CVE-2024-46693 is a medium-severity vulnerability in Linux kernel, published on 13 Sep 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
soc: qcom: pmic_glink: Fix race during initialization
As pointed out by Stephen Boyd it is possible that during initialization of the pmic_glink child drivers, the protection-domain notifiers fires, and the associated work is scheduled, before the client registration returns and as a result the local "client" pointer has been initialized.
The outcome of this is a NULL pointer dereference as the "client" pointer is blindly dereferenced.
Timeline provided by Stephen: CPU0 CPU1 ---- ---- ucsi->client = NULL; devm_pmic_glink_register_client() client->pdr_notify(client->priv, pg->client_state) pmic_glink_ucsi_pdr_notify() schedule_work(&ucsi->register_work) <schedule away> pmic_glink_ucsi_register() ucsi_register() pmic_glink_ucsi_read_version() pmic_glink_ucsi_read() pmic_glink_ucsi_read() pmic_glink_send(ucsi->client) <client is NULL BAD> ucsi->client = client // Too late!
This code is identical across the altmode, battery manager and usci child drivers.
Resolve this by splitting the allocation of the "client" object and the registration thereof into two operations.
This only happens if the protection domain registry is populated at the time of registration, which by the introduction of commit '1ebcde047c54 ("soc: qcom: add pd-mapper implementation")' became much more likely.
Weakness: CWE-476
Which versions are affected by CVE-2024-46693?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-46693?
Apply the vendor's patch.
Is CVE-2024-46693 being exploited?
There is no known exploitation of CVE-2024-46693 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-49260, BELL-CVE-2024-46693, DEBIAN-CVE-2024-46693, GHSA-5qvx-cmvh-v55m, UBUNTU-CVE-2024-46693.