Bug 2429110 (CVE-2025-68799)

Summary: CVE-2025-68799 kernel: Linux kernel (caif): Integer underflow leads to memory exhaustion and information disclosure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's caif component. A remote attacker could send a specially crafted packet with a small length field to an interface with Frame Check Sequence (FCS) disabled. This could lead to an integer underflow, causing memory exhaustion, kernel instability, and potential information disclosure if padding contains uninitialized kernel memory.
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Description OSIDB Bzimport 2026-01-13 16:07:27 UTC 
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.
Comment 1 Jon Moroney 2026-01-14 22:33:24 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026011307-CVE-2025-68799-b0dd@gregkh/T