FKIE_CVE-2026-90206

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-09-17 17:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: nvmet: fix max_qid race between configfs and controller allocation The function nvmet_subsys_attr_qid_max_store() can race against nvmet_alloc_ctrl() when a subsystem's max_qid limit is modified. Suppose max_qid is currently 64. If nvmet_alloc_ctrl() executes: ctrl->sqs = kzalloc_objs(struct nvmet_sq *, subsys->max_qid + 1); and at this exact point, a userspace process changes max_qid to 128, nvmet_subsys_attr_qid_max_store() will set the new max_qid value. It attempts to delete active controllers to force a reconnect, but the new controller won't be deleted because it hasn't been added to the subsys->ctrls list yet. nvmet_alloc_ctrl() then proceeds and adds the new controller to the subsys->ctrls list. Later, when nvmet_install_queue() is called, it will see max_qid set to 128, but the memory allocated for sqs is only sized for 64 entries. This results in a KASAN out-of-bounds warning and potential memory corruptions. Fix this by protecting the queue allocations and list insertion in nvmet_alloc_ctrl() with down_read(&nvmet_config_sem). Because nvmet_subsys_attr_qid_max_store() acquires down_write(&nvmet_config_sem) to modify the attribute, this safely prevents the configfs writer from modifying max_qid during controller creation. Copy the max_qid from the subsystem to the controller's structure during the allocation; ctrl->max_qid never changes as long as the controller remains in LIVE state, so this will prevent similar race conditions.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2c23fc91789dfd9db746edb3ae9b90d65fabd410
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f1a8846e06388113dfdbb89dee005083fa9afdf9
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/target/admin-cmd.c",
            "drivers/nvme/target/core.c",
            "drivers/nvme/target/fabrics-cmd.c",
            "drivers/nvme/target/nvmet.h",
            "drivers/nvme/target/pci-epf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2c23fc91789dfd9db746edb3ae9b90d65fabd410",
              "status": "affected",
              "version": "3e980f5995e0bb4d86fef873a9c9ad66721580d0",
              "versionType": "git"
            },
            {
              "lessThan": "f1a8846e06388113dfdbb89dee005083fa9afdf9",
              "status": "affected",
              "version": "3e980f5995e0bb4d86fef873a9c9ad66721580d0",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/target/admin-cmd.c",
            "drivers/nvme/target/core.c",
            "drivers/nvme/target/fabrics-cmd.c",
            "drivers/nvme/target/nvmet.h",
            "drivers/nvme/target/pci-epf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "lessThan": "6.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "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\nnvmet: fix max_qid race between configfs and controller allocation\n\nThe function nvmet_subsys_attr_qid_max_store() can race against\nnvmet_alloc_ctrl() when a subsystem\u0027s max_qid limit is modified.\n\nSuppose max_qid is currently 64. If nvmet_alloc_ctrl() executes:\nctrl-\u003esqs = kzalloc_objs(struct nvmet_sq *, subsys-\u003emax_qid + 1);\nand at this exact point, a userspace process changes max_qid to 128,\nnvmet_subsys_attr_qid_max_store() will set the new max_qid value. It\nattempts to delete active controllers to force a reconnect, but the\nnew controller won\u0027t be deleted because it hasn\u0027t been added to the\nsubsys-\u003ectrls list yet.\n\nnvmet_alloc_ctrl() then proceeds and adds the new controller to the\nsubsys-\u003ectrls list. Later, when nvmet_install_queue() is called, it\nwill see max_qid set to 128, but the memory allocated for sqs is only\nsized for 64 entries. This results in a KASAN out-of-bounds warning\nand potential memory corruptions.\n\nFix this by protecting the queue allocations and list insertion in\nnvmet_alloc_ctrl() with down_read(\u0026nvmet_config_sem). Because\nnvmet_subsys_attr_qid_max_store() acquires down_write(\u0026nvmet_config_sem)\nto modify the attribute, this safely prevents the configfs writer from\nmodifying max_qid during controller creation.\n\nCopy the max_qid from the subsystem to the controller\u0027s structure\nduring the allocation; ctrl-\u003emax_qid never changes as long as the\ncontroller remains in LIVE state, so this will prevent similar race\nconditions."
    }
  ],
  "id": "CVE-2026-90206",
  "lastModified": "2026-09-17T17:17:15.700",
  "metrics": {},
  "published": "2026-09-17T17:17:15.700",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2c23fc91789dfd9db746edb3ae9b90d65fabd410"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f1a8846e06388113dfdbb89dee005083fa9afdf9"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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