CVE-2025-39843

Advisory lineage Upstream: 0 Downstream: 19
Modified
Published: 19 Sept 2025, 15:26
Last modified:12 May 2026, 12:07

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.01% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

19 Sept 2025, 15:26
Published
Vulnerability first disclosed
12 May 2026, 12:07
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: mm: slub: avoid wake up kswapd in set_track_prepare set_track_prepare() can incur lock recursion. The issue is that it is called from hrtimer_start_range_ns holding the per_cpu(hrtimer_bases)[n].lock, but when enabled CONFIG_DEBUG_OBJECTS_TIMERS, may wake up kswapd in set_track_prepare, and try to hold the per_cpu(hrtimer_bases)[n].lock. Avoid deadlock caused by implicitly waking up kswapd by passing in allocation flags, which do not contain __GFP_KSWAPD_RECLAIM in the debug_objects_fill_pool() case. Inside stack depot they are processed by gfp_nested_mask(). Since ___slab_alloc() has preemption disabled, we mask out __GFP_DIRECT_RECLAIM from the flags there. The oops looks something like: BUG: spinlock recursion on CPU#3, swapper/3/0 lock: 0xffffff8a4bf29c80, .magic: dead4ead, .owner: swapper/3/0, .owner_cpu: 3 Hardware name: Qualcomm Technologies, Inc. Popsicle based on SM8850 (DT) Call trace: spin_bug+0x0 _raw_spin_lock_irqsave+0x80 hrtimer_try_to_cancel+0x94 task_contending+0x10c enqueue_dl_entity+0x2a4 dl_server_start+0x74 enqueue_task_fair+0x568 enqueue_task+0xac do_activate_task+0x14c ttwu_do_activate+0xcc try_to_wake_up+0x6c8 default_wake_function+0x20 autoremove_wake_function+0x1c __wake_up+0xac wakeup_kswapd+0x19c wake_all_kswapds+0x78 __alloc_pages_slowpath+0x1ac __alloc_pages_noprof+0x298 stack_depot_save_flags+0x6b0 stack_depot_save+0x14 set_track_prepare+0x5c ___slab_alloc+0xccc __kmalloc_cache_noprof+0x470 __set_page_owner+0x2bc post_alloc_hook[jt]+0x1b8 prep_new_page+0x28 get_page_from_freelist+0x1edc __alloc_pages_noprof+0x13c alloc_slab_page+0x244 allocate_slab+0x7c ___slab_alloc+0x8e8 kmem_cache_alloc_noprof+0x450 debug_objects_fill_pool+0x22c debug_object_activate+0x40 enqueue_hrtimer[jt]+0xdc hrtimer_start_range_ns+0x5f8 ...

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 3%

Techniques & Countermeasures

  • CWE-667•Improper Locking

    The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Systems

  • debian•debian_linux

    11.0

  • linux•linux

    ≥ 5cf909c553e9efed573811de4b3f5172898d5515, < 994b03b9605d36d814c611385fbf90ca6db20aa8 | ≥ 5cf909c553e9efed573811de4b3f5172898d5515, < 522ffe298627cfe72539d72167c2e20e72b5e856 | ≥ 5cf909c553e9efed573811de4b3f5172898d5515, < 243b705a90ed8449f561a271cf251fd2e939f3db | ≥ 5cf909c553e9efed573811de4b3f5172898d5515, < eb3240ffd243bfb8b1e9dc568d484ecf9fd660ab | ≥ 5cf909c553e9efed573811de4b3f5172898d5515, < 850470a8413a8a78e772c4f6bd9fe81ec6bd5b0f | 5.19

  • linux•linux_kernel

    ≥ 5.19, < 6.1.151 | ≥ 6.2, < 6.6.105 | ≥ 6.7, < 6.12.46 | ≥ 6.13, < 6.16.6 | 6.17:rc1 | 6.17:rc2 | 6.17:rc3 | 6.17:rc4

References (7)