CVE-2025-21851

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix softlockup in arena_map_free on 64k page kernel On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y, arena_htab tests cause a segmentation fault and soft lockup. The same failure is not observed with 4k pages on aarch64. It turns out arena_map_free() is calling apply_to_existing_page_range() with the address returned by bpf_arena_get_kern_vm_start(). If this address is not page-aligned the code ends up calling apply_to_pte_range() with that unaligned address causing soft lockup. Fix it by round up GUARD_SZ to PAGE_SIZE << 1 so that the division by 2 in bpf_arena_get_kern_vm_start() returns a page-aligned value.

CVSS v3 3.3 LOW

3.3^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.8 / Impact : 1.4

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/517e8a7835e8cfb398a0aeb0133de50e31cae32b	Patch
https://git.kernel.org/stable/c/787d556a3de447e70964a4bdeba9196f62a62b1e	Patch
https://git.kernel.org/stable/c/c1f3f3892d4526f18aaeffdb6068ce861e793ee3	Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:6.9:-::::::
	cpe:2.3:o:linux:linux_kernel:6.14:rc1::::::
	cpe:2.3:o:linux:linux_kernel:6.14:rc2::::::
	cpe:2.3:o:linux:linux_kernel:6.14:rc3::::::

History

No history.

Information

Published : 2025-03-12 10:15

Updated : 2025-10-01 20:18

NVD link : CVE-2025-21851

Mitre link : CVE-2025-21851

CVE.ORG link : CVE-2025-21851

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-667

Improper Locking

{"id": "CVE-2025-21851", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.3, "attackVector": "LOCAL", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 1.8}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.3, "attackVector": "LOCAL", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 1.8}]}, "published": "2025-03-12T10:15:17.703", "references": [{"url": "https://git.kernel.org/stable/c/517e8a7835e8cfb398a0aeb0133de50e31cae32b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/787d556a3de447e70964a4bdeba9196f62a62b1e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c1f3f3892d4526f18aaeffdb6068ce861e793ee3", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-667"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-667"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix softlockup in arena_map_free on 64k page kernel\n\nOn an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y,\narena_htab tests cause a segmentation fault and soft lockup.\nThe same failure is not observed with 4k pages on aarch64.\n\nIt turns out arena_map_free() is calling\napply_to_existing_page_range() with the address returned by\nbpf_arena_get_kern_vm_start(). If this address is not page-aligned\nthe code ends up calling apply_to_pte_range() with that unaligned\naddress causing soft lockup.\n\nFix it by round up GUARD_SZ to PAGE_SIZE << 1 so that the\ndivision by 2 in bpf_arena_get_kern_vm_start() returns\na page-aligned value."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf: Arregla el bloqueo suave en arena_map_free en un kernel de p\u00e1gina de 64k En un kernel aarch64 con CONFIG_PAGE_SIZE_64KB=y, las pruebas arena_htab causan un fallo de segmentaci\u00f3n y un bloqueo suave. No se observa el mismo fallo con p\u00e1ginas de 4k en aarch64. Resulta que arena_map_free() est\u00e1 llamando a apply_to_existing_page_range() con la direcci\u00f3n devuelta por bpf_arena_get_kern_vm_start(). Si esta direcci\u00f3n no est\u00e1 alineada con la p\u00e1gina, el c\u00f3digo termina llamando a apply_to_pte_range() con esa direcci\u00f3n no alineada, lo que causa un bloqueo suave. Arr\u00e9glelo redondeando GUARD_SZ a PAGE_SIZE << 1 para que la divisi\u00f3n por 2 en bpf_arena_get_kern_vm_start() devuelva un valor alineado con la p\u00e1gina."}], "lastModified": "2025-10-01T20:18:29.183", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3E513C8F-C336-4B36-A14B-ABDBD0C33C40", "versionEndExcluding": "6.12.17", "versionStartIncluding": "6.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "72E69ABB-9015-43A6-87E1-5150383CFFD9", "versionEndExcluding": "6.13.5", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3F2A4A3D-068A-4CF2-A09F-9C7937DDB0A5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "186716B6-2B66-4BD0-852E-D48E71C0C85F"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0D3E781C-403A-498F-9DA9-ECEE50F41E75"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "66619FB8-0AAF-4166-B2CF-67B24143261D"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}