CVE-2026-98537
Full vulnerability record from the local CVENow database.
Description
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.
View original CVE JSON
{
"id": "CVE-2026-98537",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-18T16:17:05.480",
"lastModified": "2026-10-19T10:19:09.357",
"vulnStatus": "Received",
"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->current_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->current_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->current_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."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"kernel/workqueue.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "8ffececcb88262389b4f91fed0fe4884b68204bc",
"versionType": "git",
"status": "affected"
},
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "9bb739a5c5a570c28a62afb98e9326e2a49743c1",
"versionType": "git",
"status": "affected"
},
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "cc190a6a1d20b87e6a9435202fc2a3bd84c79fb3",
"versionType": "git",
"status": "affected"
},
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "513121e69388604619ea8c0ee07e86a3d1b5b5dc",
"versionType": "git",
"status": "affected"
},
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "0c6b9b1e295aeff1132ac7aa738148cc65f06485",
"versionType": "git",
"status": "affected"
},
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "1dccf5dc2f8fe688270b261ca4216e03c6a1e674",
"versionType": "git",
"status": "affected"
},
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "f97e6d0572d1b39998e053732332bc3cfdd0b9aa",
"versionType": "git",
"status": "affected"
},
{
"version": "fca839c00a12d682cb59b3b620d109a1d850b262",
"lessThan": "db6365ced4d5855e321f772b240c0e473bcfcdd5",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"kernel/workqueue.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.5",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.5",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.271",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.222",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.189",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.158",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.112",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.55",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.9",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"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"
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{
"url": "https://git.kernel.org/stable/c/8ffececcb88262389b4f91fed0fe4884b68204bc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"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",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}