{"cve":"CVE-2025-39843","nvd":{"published":"2025-09-19T16:15:43.047","modified":"2026-10-19T21:10:00.160","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: slub: avoid wake up kswapd in set_track_prepare\n\nset_track_prepare() can incur lock recursion.\nThe issue is that it is called from hrtimer_start_range_ns\nholding the per_cpu(hrtimer_bases)[n].lock, but when enabled\nCONFIG_DEBUG_OBJECTS_TIMERS, may wake up kswapd in set_track_prepare,\nand try to hold the per_cpu(hrtimer_bases)[n].lock.\n\nAvoid deadlock caused by implicitly waking up kswapd by passing in\nallocation flags, which do not contain __GFP_KSWAPD_RECLAIM in the\ndebug_objects_fill_pool() case. Inside stack depot they are processed by\ngfp_nested_mask().\nSince ___slab_alloc() has preemption disabled, we mask out\n__GFP_DIRECT_RECLAIM from the flags there.\n\nThe oops looks something like:\n\nBUG: spinlock recursion on CPU#3, swapper/3/0\n lock: 0xffffff8a4bf29c80, .magic: dead4ead, .owner: swapper/3/0, .owner_cpu: 3\nHardware name: Qualcomm Technologies, Inc. Popsicle based on SM8850 (DT)\nCall trace:\nspin_bug+0x0\n_raw_spin_lock_irqsave+0x80\nhrtimer_try_to_cancel+0x94\ntask_contending+0x10c\nenqueue_dl_entity+0x2a4\ndl_server_start+0x74\nenqueue_task_fair+0x568\nenqueue_task+0xac\ndo_activate_task+0x14c\nttwu_do_activate+0xcc\ntry_to_wake_up+0x6c8\ndefault_wake_function+0x20\nautoremove_wake_function+0x1c\n__wake_up+0xac\nwakeup_kswapd+0x19c\nwake_all_kswapds+0x78\n__alloc_pages_slowpath+0x1ac\n__alloc_pages_noprof+0x298\nstack_depot_save_flags+0x6b0\nstack_depot_save+0x14\nset_track_prepare+0x5c\n___slab_alloc+0xccc\n__kmalloc_cache_noprof+0x470\n__set_page_owner+0x2bc\npost_alloc_hook[jt]+0x1b8\nprep_new_page+0x28\nget_page_from_freelist+0x1edc\n__alloc_pages_noprof+0x13c\nalloc_slab_page+0x244\nallocate_slab+0x7c\n___slab_alloc+0x8e8\nkmem_cache_alloc_noprof+0x450\ndebug_objects_fill_pool+0x22c\ndebug_object_activate+0x40\nenqueue_hrtimer[jt]+0xdc\nhrtimer_start_range_ns+0x5f8\n...","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/243b705a90ed8449f561a271cf251fd2e939f3db","https://git.kernel.org/stable/c/522ffe298627cfe72539d72167c2e20e72b5e856","https://git.kernel.org/stable/c/850470a8413a8a78e772c4f6bd9fe81ec6bd5b0f","https://git.kernel.org/stable/c/994b03b9605d36d814c611385fbf90ca6db20aa8","https://git.kernel.org/stable/c/eb3240ffd243bfb8b1e9dc568d484ecf9fd660ab"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-39843","score":0.00117,"percentile":0.01686,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}