PT-2025-4351 · Linux+5 · Linux Kernel+5

Michal Luczaj

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Published

2025-01-10

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Updated

2025-10-03

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CVE-2025-21670

CVSS v3.1

5.5

Medium

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.6.73/6.12.10
Description The issue is related to a null pointer dereference in the Linux kernel's vsock/bpf module. This can occur when a socket has a null transport, for example, after a failed connect() call. The error can cause a kernel crash, leading to a denial of service. The vsock bpf recvmsg() function needs to check the vsk->transport especially for connected sockets (stream/seqpacket) to prevent this issue.
Recommendations To resolve the issue, update the Linux kernel to a version newer than 6.6.73/6.12.10. As a temporary workaround, consider restricting access to the vsock bpf recvmsg() function, especially for connected sockets, until a patch is available. Additionally, ensure that the vsk->transport is properly checked in the vsock bpf recvmsg() function to prevent null pointer dereferences.

Exploit

Fix

NULL Pointer Dereference

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Weakness Enumeration

Related Identifiers

ALT-PU-2025-12647
ALT-PU-2025-3467
ALT-PU-2025-3500
AZL-56396
BDU:2025-01465
CVE-2025-21670
OESA-2025-1093
OESA-2025-1097
OPENSUSE-SU-2025_0499-1
OPENSUSE-SU-2025_0557-1
OPENSUSE-SU-2025_0847-1
SUSE-SU-2025:0499-1
SUSE-SU-2025:0557-1
SUSE-SU-2025:0564-1
SUSE-SU-2025:0847-1
SUSE-SU-2025:20190-1
SUSE-SU-2025:20192-1
SUSE-SU-2025:20260-1
SUSE-SU-2025:20270-1
SUSE-SU-2025_0499-1
SUSE-SU-2025_0557-1
SUSE-SU-2025_0847-1
USN-7445-1
USN-7448-1
USN-7595-1
USN-7595-2
USN-7595-3
USN-7595-4
USN-7595-5
USN-7596-1
USN-7596-2
USN-7653-1

Affected Products

Alt Linux
Astra Linux
Linuxmint
Linux Kernel
Suse
Ubuntu