FKIE_CVE-2026-98366

Vulnerability from fkie_nvd - Published: 2026-10-06 09:18 - Updated: 2026-10-06 09:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: validate access flags before swapping the MR's PD rxe_rereg_user_mr() reassigns mr->ibmr.pd first and only then validates the IB_MR_REREG_ACCESS argument: if (flags & IB_MR_REREG_PD) { rxe_put(old_pd); rxe_get(pd); mr->ibmr.pd = ibpd; } if (flags & IB_MR_REREG_ACCESS) { if (access & ~RXE_ACCESS_SUPPORTED_MR) return ERR_PTR(-EOPNOTSUPP); mr->access = access; } Both flags pass the entry check because RXE_MR_REREG_SUPPORTED is IB_MR_REREG_PD | IB_MR_REREG_ACCESS, so a caller can reach the access check with mr->ibmr.pd already reassigned. mr->ibmr.pd is owned by the core, which adjusts pd->usecnt only on the success path: ib_uverbs_rereg_mr() jumps to put_new_uobj on a driver error without undoing the reassignment, so mr->pd == new_pd while the usecnts still charge the MR to orig_pd. ib_dereg_mr_user() then decrements new_pd, whose count can reach zero while a memory window still references it; uverbs_free_pd() frees the PD on that count alone and rxe_mw_cleanup() writes to freed memory: BUG: KASAN: slab-use-after-free in __rxe_put+0x31/0xa0 Write of size 4 at addr ffff8881301dd690 by task rxe_poc/591 __rxe_put+0x31/0xa0 rxe_mw_cleanup+0x42/0x200 __rxe_cleanup+0x115/0x370 rxe_dealloc_mw+0x4c/0x80 Allocated by task 591: ib_uverbs_alloc_pd+0x258/0x540 Freed by task 591: ib_dealloc_pd_user+0x174/0x210 uverbs_free_pd+0x8d/0xc0 ib_uverbs_dealloc_pd+0x18e/0x1d0 Validate the access flags before mutating any state so the callback either applies every requested change or none.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/08f12745cb72981aa2cabe214af0c7a42a856f0a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7230cc456d4bb2221c20c5f1d22b38b8576aa16f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ae36a5b609ae79f4de966328b78d2584be9719a4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fe602c91a52e161ace4afd5bdb8f33270c554c6f
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_verbs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "08f12745cb72981aa2cabe214af0c7a42a856f0a",
              "status": "affected",
              "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c",
              "versionType": "git"
            },
            {
              "lessThan": "7230cc456d4bb2221c20c5f1d22b38b8576aa16f",
              "status": "affected",
              "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c",
              "versionType": "git"
            },
            {
              "lessThan": "fe602c91a52e161ace4afd5bdb8f33270c554c6f",
              "status": "affected",
              "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c",
              "versionType": "git"
            },
            {
              "lessThan": "4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8",
              "status": "affected",
              "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c",
              "versionType": "git"
            },
            {
              "lessThan": "ae36a5b609ae79f4de966328b78d2584be9719a4",
              "status": "affected",
              "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_verbs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.5"
            },
            {
              "lessThan": "6.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: validate access flags before swapping the MR\u0027s PD\n\nrxe_rereg_user_mr() reassigns mr-\u003eibmr.pd first and only then\nvalidates the IB_MR_REREG_ACCESS argument:\n\n\tif (flags \u0026 IB_MR_REREG_PD) {\n\t\trxe_put(old_pd);\n\t\trxe_get(pd);\n\t\tmr-\u003eibmr.pd = ibpd;\n\t}\n\n\tif (flags \u0026 IB_MR_REREG_ACCESS) {\n\t\tif (access \u0026 ~RXE_ACCESS_SUPPORTED_MR)\n\t\t\treturn ERR_PTR(-EOPNOTSUPP);\n\t\tmr-\u003eaccess = access;\n\t}\n\nBoth flags pass the entry check because RXE_MR_REREG_SUPPORTED is\nIB_MR_REREG_PD | IB_MR_REREG_ACCESS, so a caller can reach the access\ncheck with mr-\u003eibmr.pd already reassigned.\n\nmr-\u003eibmr.pd is owned by the core, which adjusts pd-\u003eusecnt only on the\nsuccess path: ib_uverbs_rereg_mr() jumps to put_new_uobj on a driver error\nwithout undoing the reassignment, so mr-\u003epd == new_pd while the usecnts\nstill charge the MR to orig_pd. ib_dereg_mr_user() then decrements\nnew_pd, whose count can reach zero while a memory window still references\nit; uverbs_free_pd() frees the PD on that count alone and rxe_mw_cleanup()\nwrites to freed memory:\n\n  BUG: KASAN: slab-use-after-free in __rxe_put+0x31/0xa0\n  Write of size 4 at addr ffff8881301dd690 by task rxe_poc/591\n   __rxe_put+0x31/0xa0\n   rxe_mw_cleanup+0x42/0x200\n   __rxe_cleanup+0x115/0x370\n   rxe_dealloc_mw+0x4c/0x80\n  Allocated by task 591:\n   ib_uverbs_alloc_pd+0x258/0x540\n  Freed by task 591:\n   ib_dealloc_pd_user+0x174/0x210\n   uverbs_free_pd+0x8d/0xc0\n   ib_uverbs_dealloc_pd+0x18e/0x1d0\n\nValidate the access flags before mutating any state so the callback either\napplies every requested change or none."
    }
  ],
  "id": "CVE-2026-98366",
  "lastModified": "2026-10-06T09:18:30.823",
  "metrics": {},
  "published": "2026-10-06T09:18:30.823",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/08f12745cb72981aa2cabe214af0c7a42a856f0a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7230cc456d4bb2221c20c5f1d22b38b8576aa16f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ae36a5b609ae79f4de966328b78d2584be9719a4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fe602c91a52e161ace4afd5bdb8f33270c554c6f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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