CVE-2025-21759

In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: extend RCU protection in igmp6_send() igmp6_send() can be called without RTNL or RCU being held. Extend RCU protection so that we can safely fetch the net pointer and avoid a potential UAF. Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep. Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/087c1faa594fa07a66933d750c0b2610aa1a2946	Patch
https://git.kernel.org/stable/c/0bf8e2f3768629d437a32cb824149e6e98254381	Patch
https://git.kernel.org/stable/c/638e8fe3563a82f298fe537a28d5342a97278cf1
https://git.kernel.org/stable/c/6901bbb169e3add6c037218d996790cef6b3d650
https://git.kernel.org/stable/c/7e0a818ecc4d62e7fb668ea02de0bfe8ba0b7dff
https://git.kernel.org/stable/c/81b25a07ebf53f9ef4ca8f3d96a8ddb94561dd5a	Patch
https://git.kernel.org/stable/c/8e92d6a413feaf968a33f0b439ecf27404407458	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::::::::
	cpe:2.3:o:linux:linux_kernel:6.14:rc1::::::
	cpe:2.3:o:linux:linux_kernel:6.14:rc2::::::

History

03 Oct 2026, 11:17

Type	Values Removed	Values Added
References		() https://git.kernel.org/stable/c/638e8fe3563a82f298fe537a28d5342a97278cf1 - () https://git.kernel.org/stable/c/6901bbb169e3add6c037218d996790cef6b3d650 - () https://git.kernel.org/stable/c/7e0a818ecc4d62e7fb668ea02de0bfe8ba0b7dff -

Information

Published : 2025-02-27 03:15

Updated : 2026-10-03 11:17

NVD link : CVE-2025-21759

Mitre link : CVE-2025-21759

CVE.ORG link : CVE-2025-21759

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-416

Use After Free

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"en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: extend RCU protection in igmp6_send()\n\nigmp6_send() can be called without RTNL or RCU being held.\n\nExtend RCU protection so that we can safely fetch the net pointer\nand avoid a potential UAF.\n\nNote that we no longer can use sock_alloc_send_skb() because\nipv6.igmp_sk uses GFP_KERNEL allocations which can sleep.\n\nInstead use alloc_skb() and charge the net->ipv6.igmp_sk\nsocket under RCU protection."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ipv6: mcast: extender la protecci\u00f3n RCU en igmp6_send() igmp6_send() se puede llamar sin que se mantenga RTNL o RCU. Extienda la protecci\u00f3n RCU para que podamos obtener de forma segura el puntero de red y evitar un posible UAF. Tenga en cuenta que ya no podemos usar sock_alloc_send_skb() porque ipv6.igmp_sk usa asignaciones GFP_KERNEL que pueden dormir. En su lugar, use alloc_skb() y cargue el socket net->ipv6.igmp_sk bajo la protecci\u00f3n RCU."}], "lastModified": "2026-10-03T11:17:32.400", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "80691BA5-295B-4772-9338-1D31A39548D6", "versionEndExcluding": "6.6.79", "versionStartIncluding": "2.6.26"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "13C8DB18-FC60-425F-84E5-3EDDEC61B2FC", "versionEndExcluding": "6.12.16", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2A2093ED-74A9-43F9-AC72-50030F374EA4", "versionEndExcluding": "6.13.4", "versionStartIncluding": "6.13"}, {"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"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}