FKIE_CVE-2026-90247

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: bpf: Fix mmap_lock leak in irq_work path stack_map_get_build_id_offset() introduced a per-CPU irq_work to defer mmap_read_unlock() from NMI context, and bpf_find_vma() later reused the same mmap_unlock_work. Both callers only check whether the work is busy before taking mmap_lock, so a nested caller can reuse the slot before the first caller queues it. Two read locks may then be acquired while only one deferred unlock runs, leaking a read lock and blocking exit_mmap(). Reserve the per-CPU slot before mmap_read_trylock(). Use the same wrapper in stackmap and bpf_find_vma() so both callers release the reservation on trylock failure. Keep rejecting the slot while the irq_work remains busy. Release it after the irq_work callback unlocks the mm.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/051f2da26ce377f683b938a3382e0f16d02f3139
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a052ad5edccf5319f50ed955de4368f8318a9f20
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fa9dcacdcdf487f0ffef64bf67622f1caed509f1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/mmap_unlock_work.h",
            "kernel/bpf/stackmap.c",
            "kernel/bpf/task_iter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a052ad5edccf5319f50ed955de4368f8318a9f20",
              "status": "affected",
              "version": "eac9153f2b584c702cea02c1f1a57d85aa9aea42",
              "versionType": "git"
            },
            {
              "lessThan": "051f2da26ce377f683b938a3382e0f16d02f3139",
              "status": "affected",
              "version": "eac9153f2b584c702cea02c1f1a57d85aa9aea42",
              "versionType": "git"
            },
            {
              "lessThan": "fa9dcacdcdf487f0ffef64bf67622f1caed509f1",
              "status": "affected",
              "version": "eac9153f2b584c702cea02c1f1a57d85aa9aea42",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "a7f4da875c16f3b8bef0d9ec67528111045bfcd8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f1838da73cccb238b8be4ef464fce0168dc7ba84",
              "versionType": "git"
            },
            {
              "lessThan": "4.20",
              "status": "affected",
              "version": "4.19.92",
              "versionType": "semver"
            },
            {
              "lessThan": "5.5",
              "status": "affected",
              "version": "5.4.7",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/mmap_unlock_work.h",
            "kernel/bpf/stackmap.c",
            "kernel/bpf/task_iter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.5"
            },
            {
              "lessThan": "5.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "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\nbpf: Fix mmap_lock leak in irq_work path\n\nstack_map_get_build_id_offset() introduced a per-CPU irq_work to defer\nmmap_read_unlock() from NMI context, and bpf_find_vma() later reused the\nsame mmap_unlock_work. Both callers only check whether the work is busy\nbefore taking mmap_lock, so a nested caller can reuse the slot before the\nfirst caller queues it. Two read locks may then be acquired while only one\ndeferred unlock runs, leaking a read lock and blocking exit_mmap().\n\nReserve the per-CPU slot before mmap_read_trylock(). Use the same wrapper\nin stackmap and bpf_find_vma() so both callers release the reservation on\ntrylock failure. Keep rejecting the slot while the irq_work remains busy.\nRelease it after the irq_work callback unlocks the mm."
    }
  ],
  "id": "CVE-2026-90247",
  "lastModified": "2026-09-17T17:17:20.803",
  "metrics": {},
  "published": "2026-09-17T17:17:20.803",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/051f2da26ce377f683b938a3382e0f16d02f3139"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a052ad5edccf5319f50ed955de4368f8318a9f20"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fa9dcacdcdf487f0ffef64bf67622f1caed509f1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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