Linux Kernel up to 6.12.18/6.13.6 memory_hotplug /include/linux/swapops.h state issue

Summaryinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.12.18/6.13.6. Impacted is an unknown function in the library /include/linux/swapops.h of the component memory_hotplug. Executing a manipulation can lead to state issue. This vulnerability is handled as CVE-2025-21931. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.12.18/6.13.6. This vulnerability affects some unknown functionality in the library /include/linux/swapops.h of the component memory_hotplug. The manipulation with an unknown input leads to a state issue vulnerability. The CWE definition for the vulnerability is CWE-371. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: hwpoison, memory_hotplug: lock folio before unmap hwpoisoned folio Commit b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined) add page poison checks in do_migrate_range in order to make offline hwpoisoned page possible by introducing isolate_lru_page and try_to_unmap for hwpoisoned page. However folio lock must be held before calling try_to_unmap. Add it to fix this problem. Warning will be produced if folio is not locked during unmap: ------------[ cut here ]------------ kernel BUG at ./include/linux/swapops.h:400! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 4 UID: 0 PID: 411 Comm: bash Tainted: G W 6.13.0-rc1-00016-g3c434c7ee82a-dirty #41 Tainted: [W]=WARN Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : try_to_unmap_one+0xb08/0xd3c lr : try_to_unmap_one+0x3dc/0xd3c Call trace: try_to_unmap_one+0xb08/0xd3c (P) try_to_unmap_one+0x3dc/0xd3c (L) rmap_walk_anon+0xdc/0x1f8 rmap_walk+0x3c/0x58 try_to_unmap+0x88/0x90 unmap_poisoned_folio+0x30/0xa8 do_migrate_range+0x4a0/0x568 offline_pages+0x5a4/0x670 memory_block_action+0x17c/0x374 memory_subsys_offline+0x3c/0x78 device_offline+0xa4/0xd0 state_store+0x8c/0xf0 dev_attr_store+0x18/0x2c sysfs_kf_write+0x44/0x54 kernfs_fop_write_iter+0x118/0x1a8 vfs_write+0x3a8/0x4bc ksys_write+0x6c/0xf8 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x100 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x30/0xd0 el0t_64_sync_handler+0xc8/0xcc el0t_64_sync+0x198/0x19c Code: f9407be0 b5fff320 d4210000 17ffff97 (d4210000) ---[ end trace 0000000000000000 ]---

The advisory is available at git.kernel.org. This vulnerability was named CVE-2025-21931 since 12/29/2024. The exploitation appears to be difficult. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 02/01/2026).

The vulnerability scanner Nessus provides a plugin with the ID 237099 (SUSE SLES12 Security Update : kernel (SUSE-SU-2025:01600-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.19 or 6.13.7 eliminates this vulnerability. Applying the patch 576a2f4c437c19bec7d05d05b5990f178d2b0f40/629dfc6ba5431056701d4e44830f3409b989955a/af288a426c3e3552b62595c6138ec6371a17dbba is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (237099) and CERT Bund (WID-SEC-2025-0683). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• SolarWinds Security Event Manager
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM Security Verify Access

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.13.0
• 6.13.1
• 6.13.2
• 6.13.3
• 6.13.4
• 6.13.5
• 6.13.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

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Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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