Bug 2536230 (CVE-2026-90409)
| Summary: | CVE-2026-90409 kernel: drm/panthor: Add vm_bind region with kbo range overlap check | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's `drm/panthor` driver. This vulnerability arises from a missing check that allows user-mode virtual memory (VM) bind mappings to overlap with memory regions reserved for kernel Buffer Objects (BOs). A local attacker could exploit this to cause memory corruption, potentially leading to information disclosure or denial of service. The fix introduces a check to prevent such overlaps.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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.