FKIE_CVE-2026-98537

Vulnerability from fkie_nvd - Published: 2026-10-18 16:17 - Updated: 2026-10-19 10:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: workqueue: Fix NULL current_pwq deref in flush dependency check check_flush_dependency() uses current_wq_worker() to determine whether the caller is a workqueue worker and then dereferences worker->current_pwq to test whether the current workqueue is WQ_MEM_RECLAIM. current_wq_worker() only means that %current has PF_WQ_WORKER set. A kworker can reach check_flush_dependency() while it is not executing a work item. One such path is worker_thread() acting as the pool manager, where create_worker() does GFP_KERNEL allocation and the allocation path invokes the OOM notifier. In that state worker->current_pwq is NULL because current_pwq is set only by process_one_work() and cleared again after the work function returns. [ 416.760634][ T375] Call trace: [ 416.760638][ T375] check_flush_dependency+0x80/0x120 (P) [ 416.760648][ T375] __flush_work+0x98/0x224 [ 416.760657][ T375] flush_work+0x30/0x44 [ 416.760665][ T375] ... [ 416.760710][ T375] blocking_notifier_call_chain+0x58/0xa0 [ 416.760719][ T375] out_of_memory+0xb4/0x458 [ 416.760730][ T375] __alloc_pages_may_oom+0x11c/0x1a8 [ 416.760739][ T375] __alloc_pages_slowpath+0x314/0x46c [ 416.760746][ T375] __alloc_frozen_pages_noprof+0x110/0x1a4 [ 416.760753][ T375] new_slab+0x12c/0x484 [ 416.760759][ T375] ___slab_alloc+0x7a8/0xc7c [ 416.760765][ T375] __slab_alloc+0x74/0xd8 [ 416.760772][ T375] __kmalloc_cache_node_noprof+0x2ac/0x304 [ 416.760779][ T375] alloc_worker+0x28/0x60 [ 416.760785][ T375] create_worker+0x4c/0x20c [ 416.760790][ T375] worker_thread+0xe8/0x2b8 [ 416.760796][ T375] kthread+0x1a8/0x200 [ 416.760805][ T375] ret_from_fork+0x10/0x20 Guard the WQ_MEM_RECLAIM-worker warning with worker->current_pwq. If the kworker is not currently executing a work item, there is no current workqueue to diagnose with that warning. The PF_MEMALLOC warning is left unchanged so explicit reclaim context flushing a !WQ_MEM_RECLAIM target is still reported.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0c6b9b1e295aeff1132ac7aa738148cc65f06485
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1dccf5dc2f8fe688270b261ca4216e03c6a1e674
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/513121e69388604619ea8c0ee07e86a3d1b5b5dc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8ffececcb88262389b4f91fed0fe4884b68204bc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9bb739a5c5a570c28a62afb98e9326e2a49743c1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cc190a6a1d20b87e6a9435202fc2a3bd84c79fb3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/db6365ced4d5855e321f772b240c0e473bcfcdd5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f97e6d0572d1b39998e053732332bc3cfdd0b9aa
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/workqueue.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "8ffececcb88262389b4f91fed0fe4884b68204bc",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            },
            {
              "lessThan": "9bb739a5c5a570c28a62afb98e9326e2a49743c1",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            },
            {
              "lessThan": "cc190a6a1d20b87e6a9435202fc2a3bd84c79fb3",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            },
            {
              "lessThan": "513121e69388604619ea8c0ee07e86a3d1b5b5dc",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            },
            {
              "lessThan": "0c6b9b1e295aeff1132ac7aa738148cc65f06485",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            },
            {
              "lessThan": "1dccf5dc2f8fe688270b261ca4216e03c6a1e674",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            },
            {
              "lessThan": "f97e6d0572d1b39998e053732332bc3cfdd0b9aa",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            },
            {
              "lessThan": "db6365ced4d5855e321f772b240c0e473bcfcdd5",
              "status": "affected",
              "version": "fca839c00a12d682cb59b3b620d109a1d850b262",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/workqueue.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.5"
            },
            {
              "lessThan": "4.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.271",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.222",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.189",
              "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": "6.18.55",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "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\nworkqueue: Fix NULL current_pwq deref in flush dependency check\n\ncheck_flush_dependency() uses current_wq_worker() to determine whether\nthe caller is a workqueue worker and then dereferences worker-\u003ecurrent_pwq\nto test whether the current workqueue is WQ_MEM_RECLAIM.\n\ncurrent_wq_worker() only means that %current has PF_WQ_WORKER set. A\nkworker can reach check_flush_dependency() while it is not executing a\nwork item. One such path is worker_thread() acting as the pool manager,\nwhere create_worker() does GFP_KERNEL allocation and the allocation path\ninvokes the OOM notifier. In that state worker-\u003ecurrent_pwq is NULL\nbecause current_pwq is set only by process_one_work() and cleared again\nafter the work function returns.\n\n[  416.760634][  T375] Call trace:\n[  416.760638][  T375]  check_flush_dependency+0x80/0x120 (P)\n[  416.760648][  T375]  __flush_work+0x98/0x224\n[  416.760657][  T375]  flush_work+0x30/0x44\n[  416.760665][  T375]  ...\n[  416.760710][  T375]  blocking_notifier_call_chain+0x58/0xa0\n[  416.760719][  T375]  out_of_memory+0xb4/0x458\n[  416.760730][  T375]  __alloc_pages_may_oom+0x11c/0x1a8\n[  416.760739][  T375]  __alloc_pages_slowpath+0x314/0x46c\n[  416.760746][  T375]  __alloc_frozen_pages_noprof+0x110/0x1a4\n[  416.760753][  T375]  new_slab+0x12c/0x484\n[  416.760759][  T375]  ___slab_alloc+0x7a8/0xc7c\n[  416.760765][  T375]  __slab_alloc+0x74/0xd8\n[  416.760772][  T375]  __kmalloc_cache_node_noprof+0x2ac/0x304\n[  416.760779][  T375]  alloc_worker+0x28/0x60\n[  416.760785][  T375]  create_worker+0x4c/0x20c\n[  416.760790][  T375]  worker_thread+0xe8/0x2b8\n[  416.760796][  T375]  kthread+0x1a8/0x200\n[  416.760805][  T375]  ret_from_fork+0x10/0x20\n\nGuard the WQ_MEM_RECLAIM-worker warning with worker-\u003ecurrent_pwq. If the\nkworker is not currently executing a work item, there is no current\nworkqueue to diagnose with that warning. The PF_MEMALLOC warning is left\nunchanged so explicit reclaim context flushing a !WQ_MEM_RECLAIM target\nis still reported."
    }
  ],
  "id": "CVE-2026-98537",
  "lastModified": "2026-10-19T10:19:09.357",
  "metrics": {},
  "published": "2026-10-18T16:17:05.480",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0c6b9b1e295aeff1132ac7aa738148cc65f06485"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1dccf5dc2f8fe688270b261ca4216e03c6a1e674"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/513121e69388604619ea8c0ee07e86a3d1b5b5dc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8ffececcb88262389b4f91fed0fe4884b68204bc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9bb739a5c5a570c28a62afb98e9326e2a49743c1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc190a6a1d20b87e6a9435202fc2a3bd84c79fb3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/db6365ced4d5855e321f772b240c0e473bcfcdd5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f97e6d0572d1b39998e053732332bc3cfdd0b9aa"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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