CVE-2025-68799

caif: fix integer underflow in cffrml_receive()

Published Jan 13, 2026 CVSS 3.1 · 8.1 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

caif: fix integer underflow in cffrml_receive()

The cffrml_receive() function extracts a length field from the packet
header and, when FCS is disabled, subtracts 2 from this length without
validating that len >= 2.

If an attacker sends a malicious packet with a length field of 0 or 1
to an interface with FCS disabled, the subtraction causes an integer
underflow.

This can lead to memory exhaustion and kernel instability, potential
information disclosure if padding contains uninitialized kernel memory.

Fix this by validating that len >= 2 before performing the subtraction.

Analysis

No analysis available yet

Remediation

No remediation available yet

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4475-1 linux security update
Debian DLA Debian DLA DLA-4476-1 linux-6.1 security update
Debian DSA Debian DSA DSA-6126-1 linux security update
Debian DSA Debian DSA DSA-6127-1 linux security update
Ubuntu USN Ubuntu USN USN-8096-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8096-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8096-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8096-4 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8096-5 Linux kernel (NVIDIA Tegra IGX) vulnerabilities
Ubuntu USN Ubuntu USN USN-8116-1 Linux kernel (Intel IoTG Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8141-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8163-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8163-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8177-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8179-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8177-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8183-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8184-1 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8179-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8185-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8179-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8183-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8203-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8204-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8185-2 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8179-4 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8243-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8245-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8257-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8258-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8260-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8261-1 Linux kernel (Xilinx) vulnerabilities
Ubuntu USN Ubuntu USN USN-8265-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8440-1 Linux kernel (Azure) vulnerabilities
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'}

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: caif: fix integer underflow in cffrml_receive() The cffrml_receive() function extracts a length field from the packet header and, when FCS is disabled, subtracts 2 from this length without validating that len >= 2. If an attacker sends a malicious packet with a length field of 0 or 1 to an interface with FCS disabled, the subtraction causes an integer underflow. This can lead to memory exhaustion and kernel instability, potential information disclosure if padding contains uninitialized kernel memory. Fix this by validating that len >= 2 before performing the subtraction.
Title caif: fix integer underflow in cffrml_receive()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

No weakness.

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Aug 5, 2026, 12:11 PM
Reserved
Dec 24, 2025, 10:30 AM
Status
Deferred
Published
Jan 13, 2026, 4:16 PM
Modified
Jul 30, 2026, 6:24 AM
Severity
Public date
Jan 13, 2026, 12:00 AM