Vulnerability-Lookup

FKIE_CVE-2026-90181

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-10-19 09:19

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: ublk: avoid teardown retry loop on xarray allocation failure __ublk_shmem_remove_ranges() removes matching maple tree ranges in batches, but first stores each range into a temporary xarray so that the pages can be unpinned after dropping the maple tree lock. That temporary xarray is filled under the maple tree lock with xa_store(..., GFP_ATOMIC). If the store fails before mas_erase(), the current range is left in the tree and the helper returns false. The outer ublk_shmem_remove_ranges() loop then immediately retries the same range. While the atomic allocation keeps failing, the teardown path has no forward progress. The issue can be reproduced with radix_tree_node failslab injection after a SHMEM_ZC buffer has already been registered: # Kernel config: # CONFIG_BLK_DEV_UBLK=y # CONFIG_DEBUG_FS=y # CONFIG_FAULT_INJECTION=y # CONFIG_FAULT_INJECTION_DEBUG_FS=y # CONFIG_FAILSLAB=y echo 10 > /proc/sys/vm/nr_hugepages mkdir -p /tmp/htlb mount -t hugetlbfs none /tmp/htlb fallocate -l 4M /tmp/htlb/ublk_buf dev_id=$(kublk add -t null --shmem_zc \ --htlb /tmp/htlb/ublk_buf | awk -F '[ :]' '/dev id/ {print $3}') echo 1 > /sys/kernel/slab/radix_tree_node/failslab echo Y > /sys/kernel/debug/failslab/cache-filter echo Y > /sys/kernel/debug/failslab/ignore-gfp-wait echo 1 > /sys/kernel/debug/failslab/interval echo -1 > /sys/kernel/debug/failslab/times echo 100 > /sys/kernel/debug/failslab/probability kublk del -n "$dev_id" On the unfixed kernel the delete command was still running after 3 seconds. Disabling failslab made it return. The fault-injection stack showed: should_failslab kmem_cache_alloc_lru_noprof __xas_nomem __xa_store xa_store __ublk_shmem_remove_ranges ublk_cdev_rel ublk_ctrl_del_dev Remove the allocation from the teardown loop. Keep the existing batch limit, but collect {base_pfn, nr_pages} pairs in a fixed-size stack array. Once a matching range is found, the range is erased from the maple tree before dropping the lock, so each successful scan makes progress without depending on any GFP_ATOMIC allocation. With the same failslab settings, the fixed kernel completed "kublk del -n $dev_id" successfully in about 45 ms.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/4fd66a7f829f3f38f92a79081f0f2688aed644f0
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b9cc6cc74daf6fef533dbe65d8cee779fea69600

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b9cc6cc74daf6fef533dbe65d8cee779fea69600",
              "status": "affected",
              "version": "309e02dccf64e1b7bd2067abedc270e33b0aadf3",
              "versionType": "git"
            },
            {
              "lessThan": "4fd66a7f829f3f38f92a79081f0f2688aed644f0",
              "status": "affected",
              "version": "309e02dccf64e1b7bd2067abedc270e33b0aadf3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "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\nublk: avoid teardown retry loop on xarray allocation failure\n\n__ublk_shmem_remove_ranges() removes matching maple tree ranges in\nbatches, but first stores each range into a temporary xarray so that the\npages can be unpinned after dropping the maple tree lock.\n\nThat temporary xarray is filled under the maple tree lock with\nxa_store(..., GFP_ATOMIC). If the store fails before mas_erase(), the\ncurrent range is left in the tree and the helper returns false. The\nouter ublk_shmem_remove_ranges() loop then immediately retries the same\nrange. While the atomic allocation keeps failing, the teardown path has\nno forward progress.\n\nThe issue can be reproduced with radix_tree_node failslab injection after\na SHMEM_ZC buffer has already been registered:\n\n  # Kernel config:\n  #   CONFIG_BLK_DEV_UBLK=y\n  #   CONFIG_DEBUG_FS=y\n  #   CONFIG_FAULT_INJECTION=y\n  #   CONFIG_FAULT_INJECTION_DEBUG_FS=y\n  #   CONFIG_FAILSLAB=y\n\n  echo 10 \u003e /proc/sys/vm/nr_hugepages\n  mkdir -p /tmp/htlb\n  mount -t hugetlbfs none /tmp/htlb\n  fallocate -l 4M /tmp/htlb/ublk_buf\n\n  dev_id=$(kublk add -t null --shmem_zc \\\n\t\t--htlb /tmp/htlb/ublk_buf |\n\t   awk -F \u0027[ :]\u0027 \u0027/dev id/ {print $3}\u0027)\n\n  echo 1 \u003e /sys/kernel/slab/radix_tree_node/failslab\n  echo Y \u003e /sys/kernel/debug/failslab/cache-filter\n  echo Y \u003e /sys/kernel/debug/failslab/ignore-gfp-wait\n  echo 1 \u003e /sys/kernel/debug/failslab/interval\n  echo -1 \u003e /sys/kernel/debug/failslab/times\n  echo 100 \u003e /sys/kernel/debug/failslab/probability\n\n  kublk del -n \"$dev_id\"\n\nOn the unfixed kernel the delete command was still running after 3\nseconds. Disabling failslab made it return. The fault-injection stack\nshowed:\n\n  should_failslab\n  kmem_cache_alloc_lru_noprof\n  __xas_nomem\n  __xa_store\n  xa_store\n  __ublk_shmem_remove_ranges\n  ublk_cdev_rel\n  ublk_ctrl_del_dev\n\nRemove the allocation from the teardown loop. Keep the existing batch\nlimit, but collect {base_pfn, nr_pages} pairs in a fixed-size stack array.\nOnce a matching range is found, the range is erased from the maple tree\nbefore dropping the lock, so each successful scan makes progress without\ndepending on any GFP_ATOMIC allocation.\n\nWith the same failslab settings, the fixed kernel completed\n\"kublk del -n $dev_id\" successfully in about 45 ms."
    }
  ],
  "id": "CVE-2026-90181",
  "lastModified": "2026-10-19T09:19:08.123",
  "metrics": {},
  "published": "2026-09-17T17:17:12.287",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4fd66a7f829f3f38f92a79081f0f2688aed644f0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b9cc6cc74daf6fef533dbe65d8cee779fea69600"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-90181 (GCVE-0-2026-90181)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:07 – Updated: 2026-10-19 08:59

Title

ublk: avoid teardown retry loop on xarray allocation failure

Summary

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6639 records in the last 180 days details

References

2 references

URL	Tags
https://git.kernel.org/stable/c/b9cc6cc74daf6fef5…
https://git.kernel.org/stable/c/4fd66a7f829f3f38f…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 309e02dccf64e1b7bd2067abedc270e33b0aadf3 , < b9cc6cc74daf6fef533dbe65d8cee779fea69600 (git) Affected: 309e02dccf64e1b7bd2067abedc270e33b0aadf3 , < 4fd66a7f829f3f38f92a79081f0f2688aed644f0 (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b9cc6cc74daf6fef533dbe65d8cee779fea69600",
              "status": "affected",
              "version": "309e02dccf64e1b7bd2067abedc270e33b0aadf3",
              "versionType": "git"
            },
            {
              "lessThan": "4fd66a7f829f3f38f92a79081f0f2688aed644f0",
              "status": "affected",
              "version": "309e02dccf64e1b7bd2067abedc270e33b0aadf3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nublk: avoid teardown retry loop on xarray allocation failure\n\n__ublk_shmem_remove_ranges() removes matching maple tree ranges in\nbatches, but first stores each range into a temporary xarray so that the\npages can be unpinned after dropping the maple tree lock.\n\nThat temporary xarray is filled under the maple tree lock with\nxa_store(..., GFP_ATOMIC). If the store fails before mas_erase(), the\ncurrent range is left in the tree and the helper returns false. The\nouter ublk_shmem_remove_ranges() loop then immediately retries the same\nrange. While the atomic allocation keeps failing, the teardown path has\nno forward progress.\n\nThe issue can be reproduced with radix_tree_node failslab injection after\na SHMEM_ZC buffer has already been registered:\n\n  # Kernel config:\n  #   CONFIG_BLK_DEV_UBLK=y\n  #   CONFIG_DEBUG_FS=y\n  #   CONFIG_FAULT_INJECTION=y\n  #   CONFIG_FAULT_INJECTION_DEBUG_FS=y\n  #   CONFIG_FAILSLAB=y\n\n  echo 10 \u003e /proc/sys/vm/nr_hugepages\n  mkdir -p /tmp/htlb\n  mount -t hugetlbfs none /tmp/htlb\n  fallocate -l 4M /tmp/htlb/ublk_buf\n\n  dev_id=$(kublk add -t null --shmem_zc \\\n\t\t--htlb /tmp/htlb/ublk_buf |\n\t   awk -F \u0027[ :]\u0027 \u0027/dev id/ {print $3}\u0027)\n\n  echo 1 \u003e /sys/kernel/slab/radix_tree_node/failslab\n  echo Y \u003e /sys/kernel/debug/failslab/cache-filter\n  echo Y \u003e /sys/kernel/debug/failslab/ignore-gfp-wait\n  echo 1 \u003e /sys/kernel/debug/failslab/interval\n  echo -1 \u003e /sys/kernel/debug/failslab/times\n  echo 100 \u003e /sys/kernel/debug/failslab/probability\n\n  kublk del -n \"$dev_id\"\n\nOn the unfixed kernel the delete command was still running after 3\nseconds. Disabling failslab made it return. The fault-injection stack\nshowed:\n\n  should_failslab\n  kmem_cache_alloc_lru_noprof\n  __xas_nomem\n  __xa_store\n  xa_store\n  __ublk_shmem_remove_ranges\n  ublk_cdev_rel\n  ublk_ctrl_del_dev\n\nRemove the allocation from the teardown loop. Keep the existing batch\nlimit, but collect {base_pfn, nr_pages} pairs in a fixed-size stack array.\nOnce a matching range is found, the range is erased from the maple tree\nbefore dropping the lock, so each successful scan makes progress without\ndepending on any GFP_ATOMIC allocation.\n\nWith the same failslab settings, the fixed kernel completed\n\"kublk del -n $dev_id\" successfully in about 45 ms."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:59:18.253Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b9cc6cc74daf6fef533dbe65d8cee779fea69600"
        },
        {
          "url": "https://git.kernel.org/stable/c/4fd66a7f829f3f38f92a79081f0f2688aed644f0"
        }
      ],
      "title": "ublk: avoid teardown retry loop on xarray allocation failure",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90181",
    "datePublished": "2026-09-17T16:07:05.725Z",
    "dateReserved": "2026-09-11T19:38:34.791Z",
    "dateUpdated": "2026-10-19T08:59:18.253Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted