Bug 2540452 (CVE-2026-97421)

Summary: CVE-2026-97421 kernel: RDMA/umem: Be careful about boundary conditions in ib_umem_find_best_pgsz()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: 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   
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A flaw was found in the Linux kernel's RDMA (Remote Direct Memory Access) subsystem. Boundary conditions in the user memory page size calculation function fail to properly handle large memory lengths and address sizes, particularly on 32-bit architectures. A local user could exploit these integer truncation and overflow conditions when mapping user memory, potentially causing memory corruption or a Denial of Service (DoS) through a system crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-24 16:53:19 UTC
In the Linux kernel, the following vulnerability has been resolved:

RDMA/umem: Be careful about boundary conditions in ib_umem_find_best_pgsz()

Several corner cases, especially important on 32 bits:

- umem->iova is u64, the function argument should pass in u64 or
  iova will be truncated
- Check that the length is not too large for the iova
- Check that lengths > 4G don't overflow the GENMASK