Bug 2536363 (CVE-2026-90270) - CVE-2026-90270 kernel: arm_mpam: Disable driver unbind to avoid UAF
Summary: CVE-2026-90270 kernel: arm_mpam: Disable driver unbind to avoid UAF
Keywords:
Status: NEW
Alias: CVE-2026-90270
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 17:33 UTC by OSIDB Bzimport
Modified: 2026-10-13 13:44 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-09-17 17:33:37 UTC
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.


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