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CVE-2025-21861— mm/migrate_device: don't add folio to be freed to LRU in migrate_device_finalize()

Quick assessment

Affected

Linux Linux

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于在迁移设备时将待释放的页面添加到LRU，可能导致内存损坏。

AI Predicted 4.4 Difficulty: Theoretical EPSS 0.24% · P14 Updated Oct 15, 2026

Possible ATT&CK Techniques 1 AI

T1499 · Endpoint Denial of Service

Affected Version Matrix 18

Vendor	Product	Version Range	Status
Linux	Linux	`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 61fa824e304ed162fe965f64999068e6fcff2059`	affected
		`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 64397b0cb7c09e3ef3f9f5c7c17299c4eebd3875`	affected
		`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 4f52f7c50f5b6f5eeb06823e21fe546d90f9c595`	affected
		`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 20fb6fc51863fbff7868de8b5f6d249d2094df1f`	affected
		`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 78f579cb7d825134e071a1714d8d0c4fd0ffe459`	affected
		`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 3f9240d59e9a95d19f06120bfd1d0e681c6c0ac7`	affected
		`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 069dd21ea8262204f94737878389c2815a054a9e`	affected
		`8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6< 41cddf83d8b00f29fd105e7a0777366edc69a5cf`	affected
… +10 more rows

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I. Basic Information for CVE-2025-21861

Vulnerability Information

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Vulnerability Title

mm/migrate_device: don't add folio to be freed to LRU in migrate_device_finalize()

Source: CVE Program / CVE List V5

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: mm/migrate_device: don't add folio to be freed to LRU in migrate_device_finalize() If migration succeeded, we called folio_migrate_flags()->mem_cgroup_migrate() to migrate the memcg from the old to the new folio. This will set memcg_data of the old folio to 0. Similarly, if migration failed, memcg_data of the dst folio is left unset. If we call folio_putback_lru() on such folios (memcg_data == 0), we will add the folio to be freed to the LRU, making memcg code unhappy. Running the hmm selftests: # ./hmm-tests ... # RUN hmm.hmm_device_private.migrate ... [ 102.078007][T14893] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x7ff27d200 pfn:0x13cc00 [ 102.079974][T14893] anon flags: 0x17ff00000020018(uptodate|dirty|swapbacked|node=0|zone=2|lastcpupid=0x7ff) [ 102.082037][T14893] raw: 017ff00000020018 dead000000000100 dead000000000122 ffff8881353896c9 [ 102.083687][T14893] raw: 00000007ff27d200 0000000000000000 00000001ffffffff 0000000000000000 [ 102.085331][T14893] page dumped because: VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled()) [ 102.087230][T14893] ------------[ cut here ]------------ [ 102.088279][T14893] WARNING: CPU: 0 PID: 14893 at ./include/linux/memcontrol.h:726 folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.090478][T14893] Modules linked in: [ 102.091244][T14893] CPU: 0 UID: 0 PID: 14893 Comm: hmm-tests Not tainted 6.13.0-09623-g6c216bc522fd #151 [ 102.093089][T14893] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 [ 102.094848][T14893] RIP: 0010:folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.096104][T14893] Code: ... [ 102.099908][T14893] RSP: 0018:ffffc900236c37b0 EFLAGS: 00010293 [ 102.101152][T14893] RAX: 0000000000000000 RBX: ffffea0004f30000 RCX: ffffffff8183f426 [ 102.102684][T14893] RDX: ffff8881063cb880 RSI: ffffffff81b8117f RDI: ffff8881063cb880 [ 102.104227][T14893] RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 [ 102.105757][T14893] R10: 0000000000000001 R11: 0000000000000002 R12: ffffc900236c37d8 [ 102.107296][T14893] R13: ffff888277a2bcb0 R14: 000000000000001f R15: 0000000000000000 [ 102.108830][T14893] FS: 00007ff27dbdd740(0000) GS:ffff888277a00000(0000) knlGS:0000000000000000 [ 102.110643][T14893] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 102.111924][T14893] CR2: 00007ff27d400000 CR3: 000000010866e000 CR4: 0000000000750ef0 [ 102.113478][T14893] PKRU: 55555554 [ 102.114172][T14893] Call Trace: [ 102.114805][T14893] <TASK> [ 102.115397][T14893] ? folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.116547][T14893] ? __warn.cold+0x110/0x210 [ 102.117461][T14893] ? folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.118667][T14893] ? report_bug+0x1b9/0x320 [ 102.119571][T14893] ? handle_bug+0x54/0x90 [ 102.120494][T14893] ? exc_invalid_op+0x17/0x50 [ 102.121433][T14893] ? asm_exc_invalid_op+0x1a/0x20 [ 102.122435][T14893] ? __wake_up_klogd.part.0+0x76/0xd0 [ 102.123506][T14893] ? dump_page+0x4f/0x60 [ 102.124352][T14893] ? folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.125500][T14893] folio_batch_move_lru+0xd4/0x200 [ 102.126577][T14893] ? __pfx_lru_add+0x10/0x10 [ 102.127505][T14893] __folio_batch_add_and_move+0x391/0x720 [ 102.128633][T14893] ? __pfx_lru_add+0x10/0x10 [ 102.129550][T14893] folio_putback_lru+0x16/0x80 [ 102.130564][T14893] migrate_device_finalize+0x9b/0x530 [ 102.131640][T14893] dmirror_migrate_to_device.constprop.0+0x7c5/0xad0 [ 102.133047][T14893] dmirror_fops_unlocked_ioctl+0x89b/0xc80 Likely, nothing else goes wrong: putting the last folio reference will remove the folio from the LRU again. So besides memcg complaining, adding the folio to be freed to the LRU is just an unnecessary step. The new flow resembles what we have in migrate_folio_move(): add the dst to the lru, rem ---truncated---

Source: CVE Program / CVE List V5

CVSS Information

N/A

Source: CVE Program / CVE List V5

Vulnerability Type

N/A

Source: CVE Program / CVE List V5

Vulnerability Title

Linux kernel 安全漏洞

Source: CNNVD (China National Vulnerability Database)

Vulnerability Description

Source: CNNVD (China National Vulnerability Database)

CVSS Information

N/A

Source: CNNVD (China National Vulnerability Database)

Vulnerability Type

N/A

Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
Linux	Linux	8763cb45ab967a92a5ee49e9c544c0f0ea90e2d6 ~ 61fa824e304ed162fe965f64999068e6fcff2059	-
Linux	Linux	4.14	-

II. Public POCs for CVE-2025-21861

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III. Intelligence Information for CVE-2025-21861

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Patches & Fixes for CVE-2025-21861 (6)

Other References for CVE-2025-21861 (2)

https://www.cve.org/CVERecord?id=CVE-2025-21861

Same Patch Batch · Linux · 2025-03-12 · 26 CVEs total

CVE-2024-58087	9.8 CRITICAL	ksmbd: fix racy issue from session lookup and expire
CVE-2025-21850	9.8 CRITICAL	nvmet: Fix crash when a namespace is disabled
CVE-2025-21855	8.6 HIGH	ibmvnic: Don't reference skb after sending to VIOS
CVE-2025-21864	7.8 HIGH	tcp: drop secpath at the same time as we currently drop dst
CVE-2024-58089	7.8 HIGH	btrfs: fix double accounting race when btrfs_run_delalloc_range() failed
CVE-2025-21858	7.8 HIGH	geneve: Fix use-after-free in geneve_find_dev().
CVE-2025-21851	7.8 HIGH	bpf: Fix softlockup in arena_map_free on 64k page kernel
CVE-2025-21844	7.5 HIGH	smb: client: Add check for next_buffer in receive_encrypted_standard()
CVE-2025-21853		bpf: avoid holding freeze_mutex during mmap operation
CVE-2024-58088		bpf: Fix deadlock when freeing cgroup storage
CVE-2025-21845		mtd: spi-nor: sst: Fix SST write failure
CVE-2025-21846		acct: perform last write from workqueue
CVE-2025-21848		nfp: bpf: Add check for nfp_app_ctrl_msg_alloc()
CVE-2025-21847		ASoC: SOF: stream-ipc: Check for cstream nullity in sof_ipc_msg_data()
CVE-2025-21849		drm/i915/gt: Use spin_lock_irqsave() in interruptible context
CVE-2025-21852		net: Add rx_skb of kfree_skb to raw_tp_null_args[].
CVE-2025-21866		powerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC
CVE-2025-21854		sockmap, vsock: For connectible sockets allow only connected
CVE-2025-21856		s390/ism: add release function for struct device
CVE-2025-21857		net/sched: cls_api: fix error handling causing NULL dereference

Showing top 20 of 26 CVEs. View all on vendor page → →

IV. Related Vulnerabilities

Same product: Linux

Same vendor: Linux