Bug 2536230 (CVE-2026-90409) - CVE-2026-90409 kernel: drm/panthor: Add vm_bind region with kbo range overlap check
Summary: CVE-2026-90409 kernel: drm/panthor: Add vm_bind region with kbo range overlap...
Keywords:
Status: NEW
Alias: CVE-2026-90409
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 17:01 UTC by OSIDB Bzimport
Modified: 2026-10-20 11:05 UTC (History)
17 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-09-17 17:01:05 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm/panthor: Add vm_bind region with kbo range overlap check

When a VM is created, caller has to specify the range of the address space
carve-out set aside for mapping kernel BO's. That means vm_bind mappings of
UM-exposed BO's should not intersect with that region, but at the moment
we're not checking this.

At first, I thought of giving these values to drm_gpuvm_init() through its
reserve_{offset, range} arguments, but it turns out that is meant for VM
address spans that are not managed through the usual drm_gpuvm split/merge
circuit, so storing the end of the user VA range at VM creation time and
doing a quick check in the vm_bind ioctl path was the simplest workaround.

The new check also makes sure vm_bind range doesn't overflow the size of a
64-bit unsigned integer. That was already being done further down the call
stack inside drm_gpuvm_sm_map -> drm_gpuvm_range_valid, but it's best to
fail early in the driver before GPUVM functions are invoked so that we
won't waste time allocating vm_bind context resources.


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