{"id":"AZL-108965","summary":"CVE-2026-98537 affecting package kernel 6.6.157.1-1","details":"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.","modified":"2026-10-19T14:16:50.029248649Z","published":"2026-10-18T16:17:05Z","upstream":["CVE-2026-98537"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98537"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-108965.json"}}],"schema_version":"1.9.0"}