Junglewise Threat Intelligence

CVE-2026-52908: Linux Kernel RDMA improper memory pinning in rereg_mr

CVE-2026-52908 · Severity: info · CVSS 0 · Published 2026-06-19

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability was identified in the Linux kernel's RDMA (Remote Direct Memory Access) subsystem, which is used for high-speed data transfers between systems. The issue occurs when a user attempts to change memory access permissions from read-only to read-write; if not properly validated, this could allow unauthorized write access to protected memory regions. This could potentially lead to data corruption or unauthorized system modifications by a local attacker.

Technical details

A vulnerability in the Linux kernel RDMA subsystem stems from improper validation during the `rereg_mr` (re-register memory region) operation. When `IB_MR_REREG_ACCESS` is used to transition a memory region from Read-Only (RO) to Read-Write (RW), the underlying `umem` structure was not always re-evaluated to ensure the memory was correctly pinned for write access. This could allow a local attacker to bypass intended memory protections. The fix introduces `ib_umem_check_rereg()` to ensure drivers verify compatibility before applying new access flags. Affected drivers include mlx4, mlx5, hns_roce, irdma, and rxe.

Affected products

  • Linux Linux Kernel 6.2 to 7.0.13

Timeline

  • 2026-06-15: disclosed: Initial patch authored by Jason Gunthorpe
  • 2026-06-19: patched: Patch committed to stable tree by Greg Kroah-Hartman
  • 2026-06-19: advisory: CVE-2026-52908 published

References

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