CVE-2026-31572

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

i2c: designware: amdisp: Fix resume-probe race condition issue

Identified resume-probe race condition in kernel v7.0 with the commit 38fa29b01a6a (i2c: designware: Combine the init functions),but this issue existed from the beginning though not detected.

The amdisp i2c device requires ISP to be in power-on state for probe to succeed. To meet this requirement, this device is added to genpd to control ISP power using runtime PM. The pm_runtime_get_sync() called before i2c_dw_probe() triggers PM resume, which powers on ISP and also invokes the amdisp i2c runtime resume before the probe completes resulting in this race condition and a NULL dereferencing issue in v7.0

Fix this race condition by using the genpd APIs directly during probe:

• Call dev_pm_genpd_resume() to Power ON ISP before probe
• Call dev_pm_genpd_suspend() to Power OFF ISP after probe
• Set the device to suspended state with pm_runtime_set_suspended()
• Enable runtime PM only after the device is fully initialized

Weakness

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Software

Extended Description

A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:

A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.

Potential Mitigations

• Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
• Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• https://git.kernel.org/stable/c/83bcea9da91965484df64a6492b89e65d41ab31c
• https://git.kernel.org/stable/c/e2f1ada8e089dd5a331bcd8b88125ae2af8d188f
• https://git.kernel.org/stable/c/e81f0341754c309e33babea2821eda8f98f0b44c