CVE-2024-46691 usb: typec: ucsi: Move unregister out of atomic section
A null pointer dereference in the Linux kernel USB Type-C UCSI driver can cause a system crash when unregistering devices from atomic context.
- 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-2024-46691?
CVE-2024-46691 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:
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.ucsi.0: failed to send UCSI write request: -5
Weakness: CWE-476
Which versions are affected by CVE-2024-46691?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-46691?
Apply the vendor's patch.
Is CVE-2024-46691 being exploited?
There is no known exploitation of CVE-2024-46691 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-46691, DEBIAN-CVE-2024-46691, GHSA-5w55-q3rh-9cgc, UBUNTU-CVE-2024-46691.