CVE-2026-90270: arm_mpam: Disable driver unbind to avoid UAF

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-17 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: arm_mpam: Disable driver unbind to avoid UAF When a user unbinds an MSC and that MSC is the only MSC left for a component then the corresponding mpam_component will be freed. If the user then goes on to read the schemata file in the resctrl filesystem then the mpam_component will be accessed from resctrl_arch_get_config() leading to a use after free. As the MPAM driver is not a module the unbind sysfs interface is the only way to trigger the remove. Instead of dealing with the complexity of allowing some unused MSC to unbind just remove the unbind sysfs interface.

Affected products

Linux kernel: 6.19 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

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