In the Linux kernel, the following vulnerability has been resolved: sockmap, vsock: For connectible sockets allow only connected sockmap expects all vsocks to have a transport assigned, which is expressed in vsock_proto::psock_update_sk_prot(). However, there is an edge case where an unconnected (connectible) socket may lose its previously assigned transport. This is handled with a NULL check in the vsock/BPF recv path. Another design detail is that listening vsocks are not supposed to have any transport assigned at all. Which implies they are not supported by the sockmap. But this is complicated by the fact that a socket, before switching to TCP_LISTEN, may have had some transport assigned during a failed connect() attempt. Hence, we may end up with a listening vsock in a sockmap, which blows up quickly: KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+ Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Call Trace: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x35a/0x700 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 For connectible sockets, instead of relying solely on the state of vsk->transport, tell sockmap to only allow those representing established connections. This aligns with the behaviour for AF_INET and AF_UNIX.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

Configuration 1 [-]

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:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*

No data.

References
Link Providers
https://git.kernel.org/stable/c/22b683217ad2112791a708693cb236507abd637a cve-icon cve-icon
https://git.kernel.org/stable/c/8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f cve-icon cve-icon
https://git.kernel.org/stable/c/cc9a7832ede53ade1ba9991f0e27314caa4029d8 cve-icon cve-icon
https://git.kernel.org/stable/c/f7b473e35986835cc2813fef7b9d40336a09247e cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025031214-CVE-2025-21854-98fb@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-21854 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-21854 cve-icon
History

Wed, 01 Oct 2025 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Sat, 12 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00021}

 epss

{'score': 0.00028}

Mon, 24 Mar 2025 03:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-395

Fri, 21 Mar 2025 07:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-395

Fri, 14 Mar 2025 02:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Moderate

Thu, 13 Mar 2025 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-476
CPEs 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:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Wed, 12 Mar 2025 09:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: sockmap, vsock: For connectible sockets allow only connected sockmap expects all vsocks to have a transport assigned, which is expressed in vsock_proto::psock_update_sk_prot(). However, there is an edge case where an unconnected (connectible) socket may lose its previously assigned transport. This is handled with a NULL check in the vsock/BPF recv path. Another design detail is that listening vsocks are not supposed to have any transport assigned at all. Which implies they are not supported by the sockmap. But this is complicated by the fact that a socket, before switching to TCP_LISTEN, may have had some transport assigned during a failed connect() attempt. Hence, we may end up with a listening vsock in a sockmap, which blows up quickly: KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+ Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Call Trace: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x35a/0x700 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 For connectible sockets, instead of relying solely on the state of vsk->transport, tell sockmap to only allow those representing established connections. This aligns with the behaviour for AF_INET and AF_UNIX.
Title sockmap, vsock: For connectible sockets allow only connected
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-03-12T09:42:08.556Z

Updated: 2025-10-01T19:26:38.493Z

Reserved: 2024-12-29T08:45:45.780Z

Link: CVE-2025-21854

cve-icon Vulnrichment

Updated: 2025-10-01T16:58:23.108Z

cve-icon NVD

Status : Modified

Published: 2025-03-12T10:15:18.190

Modified: 2025-10-01T20:18:29.553

Link: CVE-2025-21854

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-03-12T00:00:00Z

Links: CVE-2025-21854 - Bugzilla