FKIE_CVE-2026-46325

Vulnerability from fkie_nvd - Published: 2026-06-09 14:16 - Updated: 2026-06-14 06:16
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE The current implementation incorrectly handles memory regions (MRs) with page sizes different from the system PAGE_SIZE. The core issue is that rxe_set_page() is called with mr->page_size step increments, but the page_list stores individual struct page pointers, each representing PAGE_SIZE of memory. ib_sg_to_page() has ensured that when i>=1 either a) SG[i-1].dma_end and SG[i].dma_addr are contiguous or b) SG[i-1].dma_end and SG[i].dma_addr are mr->page_size aligned. This leads to incorrect iova-to-va conversion in scenarios: 1) page_size < PAGE_SIZE (e.g., MR: 4K, system: 64K): ibmr->iova = 0x181800 sg[0]: dma_addr=0x181800, len=0x800 sg[1]: dma_addr=0x173000, len=0x1000 Access iova = 0x181800 + 0x810 = 0x182010 Expected VA: 0x173010 (second SG, offset 0x10) Before fix: - index = (0x182010 >> 12) - (0x181800 >> 12) = 1 - page_offset = 0x182010 & 0xFFF = 0x10 - xarray[1] stores system page base 0x170000 - Resulting VA: 0x170000 + 0x10 = 0x170010 (wrong) 2) page_size > PAGE_SIZE (e.g., MR: 64K, system: 4K): ibmr->iova = 0x18f800 sg[0]: dma_addr=0x18f800, len=0x800 sg[1]: dma_addr=0x170000, len=0x1000 Access iova = 0x18f800 + 0x810 = 0x190010 Expected VA: 0x170010 (second SG, offset 0x10) Before fix: - index = (0x190010 >> 16) - (0x18f800 >> 16) = 1 - page_offset = 0x190010 & 0xFFFF = 0x10 - xarray[1] stores system page for dma_addr 0x170000 - Resulting VA: system page of 0x170000 + 0x10 = 0x170010 (wrong) Yi Zhang reported a kernel panic[1] years ago related to this defect. Solution: 1. Replace xarray with pre-allocated rxe_mr_page array for sequential indexing (all MR page indices are contiguous) 2. Each rxe_mr_page stores both struct page* and offset within the system page 3. Handle MR page_size != PAGE_SIZE relationships: - page_size > PAGE_SIZE: Split MR pages into multiple system pages - page_size <= PAGE_SIZE: Store offset within system page 4. Add boundary checks and compatibility validation This ensures correct iova-to-va conversion regardless of MR page size and system PAGE_SIZE relationship, while improving performance through array-based sequential access. Tests on 4K and 64K PAGE_SIZE hosts: - rdma-core/pytests $ ./build/bin/run_tests.py --dev eth0_rxe - blktest: $ TIMEOUT=30 QUICK_RUN=1 USE_RXE=1 NVMET_TRTYPES=rdma ./check nvme srp rnbd [1] https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@mail.gmail.com/T/
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/12985e5915a0b8354796efadaaeb201eed115377
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/409c2c5508f3d30627bea576f8676de523cb906e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/836f6c13c9674027793f720be3f15ecd2b90b6ca
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE\n\nThe current implementation incorrectly handles memory regions (MRs) with\npage sizes different from the system PAGE_SIZE. The core issue is that\nrxe_set_page() is called with mr-\u003epage_size step increments, but the\npage_list stores individual struct page pointers, each representing\nPAGE_SIZE of memory.\n\nib_sg_to_page() has ensured that when i\u003e=1 either\na) SG[i-1].dma_end and SG[i].dma_addr are contiguous\nor\nb) SG[i-1].dma_end and SG[i].dma_addr are mr-\u003epage_size aligned.\n\nThis leads to incorrect iova-to-va conversion in scenarios:\n\n1) page_size \u003c PAGE_SIZE (e.g., MR: 4K, system: 64K):\n   ibmr-\u003eiova = 0x181800\n   sg[0]: dma_addr=0x181800, len=0x800\n   sg[1]: dma_addr=0x173000, len=0x1000\n\n   Access iova = 0x181800 + 0x810 = 0x182010\n   Expected VA: 0x173010 (second SG, offset 0x10)\n   Before fix:\n     - index = (0x182010 \u003e\u003e 12) - (0x181800 \u003e\u003e 12) = 1\n     - page_offset = 0x182010 \u0026 0xFFF = 0x10\n     - xarray[1] stores system page base 0x170000\n     - Resulting VA: 0x170000 + 0x10 = 0x170010 (wrong)\n\n2) page_size \u003e PAGE_SIZE (e.g., MR: 64K, system: 4K):\n   ibmr-\u003eiova = 0x18f800\n   sg[0]: dma_addr=0x18f800, len=0x800\n   sg[1]: dma_addr=0x170000, len=0x1000\n\n   Access iova = 0x18f800 + 0x810 = 0x190010\n   Expected VA: 0x170010 (second SG, offset 0x10)\n   Before fix:\n     - index = (0x190010 \u003e\u003e 16) - (0x18f800 \u003e\u003e 16) = 1\n     - page_offset = 0x190010 \u0026 0xFFFF = 0x10\n     - xarray[1] stores system page for dma_addr 0x170000\n     - Resulting VA: system page of 0x170000 + 0x10 = 0x170010 (wrong)\n\nYi Zhang reported a kernel panic[1] years ago related to this defect.\n\nSolution:\n1. Replace xarray with pre-allocated rxe_mr_page array for sequential\n   indexing (all MR page indices are contiguous)\n2. Each rxe_mr_page stores both struct page* and offset within the\n   system page\n3. Handle MR page_size != PAGE_SIZE relationships:\n   - page_size \u003e PAGE_SIZE: Split MR pages into multiple system pages\n   - page_size \u003c= PAGE_SIZE: Store offset within system page\n4. Add boundary checks and compatibility validation\n\nThis ensures correct iova-to-va conversion regardless of MR page size\nand system PAGE_SIZE relationship, while improving performance through\narray-based sequential access.\n\nTests on 4K and 64K PAGE_SIZE hosts:\n- rdma-core/pytests\n  $ ./build/bin/run_tests.py  --dev eth0_rxe\n- blktest:\n  $ TIMEOUT=30 QUICK_RUN=1 USE_RXE=1 NVMET_TRTYPES=rdma ./check nvme srp rnbd\n\n[1] https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@mail.gmail.com/T/"
    }
  ],
  "id": "CVE-2026-46325",
  "lastModified": "2026-06-14T06:16:25.093",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-06-09T14:16:42.177",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/12985e5915a0b8354796efadaaeb201eed115377"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/409c2c5508f3d30627bea576f8676de523cb906e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/836f6c13c9674027793f720be3f15ecd2b90b6ca"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}


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