Description

In the Linux kernel, the following vulnerability has been resolved: iommu/sva: invalidate stale IOTLB entries for kernel address space Introduce a new IOMMU interface to flush IOTLB paging cache entries for the CPU kernel address space. This interface is invoked from the x86 architecture code that manages combined user and kernel page tables, specifically before any kernel page table page is freed and reused. This addresses the main issue with vfree() which is a common occurrence and can be triggered by unprivileged users. While this resolves the primary problem, it doesn't address some extremely rare case related to memory unplug of memory that was present as reserved memory at boot, which cannot be triggered by unprivileged users. The discussion can be found at the link below. Enable SVA on x86 architecture since the IOMMU can now receive notification to flush the paging cache before freeing the CPU kernel page table pages.

Affected Products 1

References 2

• git.kernel.org https://git.kernel.org/stable/c/9f0a7ab700f8620e433b05c57fbd26c92ea186d9
  Patch
• git.kernel.org https://git.kernel.org/stable/c/e37d5a2d60a338c5917c45296bac65da1382eda5
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/9f0a7ab700f8620e433b05c57fbd26c92ea186d9
  Patch
• git.kernel.org https://git.kernel.org/stable/c/e37d5a2d60a338c5917c45296bac65da1382eda5
  Patch