In the Linux kernel, the following vulnerability has been resolved: ip6_gre: fix hardware header length for NBMA tunnels… (CVE-2026-89562)
A vulnerability in the Linux kernel's ip6_gre module related to incorrect handling of hardware header length for NBMA tunnels has been resolved. The issue involved improper accumulation of the lower device's hardware header length into the tunnel device's hard_header_len, which was incorrect for devices using header_ops. The fix ensures that the lower device header is kept in needed_headroom and that hard_header_len is set correctly only for ARPHRD_IP6GRE devices, preserving fixed Ethernet header lengths for tap and erspan devices.
AI Analysis
Technical Summary
The Linux kernel vulnerability CVE-2026-89562 concerns the ip6_gre module's handling of hardware header length for NBMA tunnels. Specifically, ip6gre_tnl_link_config_route() incorrectly accumulates the lower device's hardware header length into dev->hard_header_len when header_ops is set. This behavior is incorrect for both users of header_ops. The fix involves keeping the lower device header in needed_headroom and setting hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, while leaving the fixed Ethernet header length unchanged for ip6gretap and ip6erspan devices.
Potential Impact
The vulnerability could cause incorrect hardware header length calculations for NBMA ip6gre tunnels, potentially affecting packet processing or tunnel device behavior. No specific exploitation details or impacts such as privilege escalation or denial of service are described in the provided data.
Mitigation Recommendations
A fix for this vulnerability has been implemented in the Linux kernel. Users should apply the official kernel updates that include this correction. Since this is a kernel-level fix, upgrading to the patched kernel version is the recommended remediation. No additional mitigation steps are indicated.
In the Linux kernel, the following vulnerability has been resolved: ip6_gre: fix hardware header length for NBMA tunnels… (CVE-2026-89562)
Description
A vulnerability in the Linux kernel's ip6_gre module related to incorrect handling of hardware header length for NBMA tunnels has been resolved. The issue involved improper accumulation of the lower device's hardware header length into the tunnel device's hard_header_len, which was incorrect for devices using header_ops. The fix ensures that the lower device header is kept in needed_headroom and that hard_header_len is set correctly only for ARPHRD_IP6GRE devices, preserving fixed Ethernet header lengths for tap and erspan devices.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vulnerability CVE-2026-89562 concerns the ip6_gre module's handling of hardware header length for NBMA tunnels. Specifically, ip6gre_tnl_link_config_route() incorrectly accumulates the lower device's hardware header length into dev->hard_header_len when header_ops is set. This behavior is incorrect for both users of header_ops. The fix involves keeping the lower device header in needed_headroom and setting hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, while leaving the fixed Ethernet header length unchanged for ip6gretap and ip6erspan devices.
Potential Impact
The vulnerability could cause incorrect hardware header length calculations for NBMA ip6gre tunnels, potentially affecting packet processing or tunnel device behavior. No specific exploitation details or impacts such as privilege escalation or denial of service are described in the provided data.
Mitigation Recommendations
A fix for this vulnerability has been implemented in the Linux kernel. Users should apply the official kernel updates that include this correction. Since this is a kernel-level fix, upgrading to the patched kernel version is the recommended remediation. No additional mitigation steps are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-672h-29w5-4fj2
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89562"]
Threat ID: 6aa4a01155bf5e2cf5a866b0
Added to database: 09/12/2026, 00:42:57 UTC
Last enriched: 09/12/2026, 01:07:14 UTC
Last updated: 09/12/2026, 01:07:14 UTC
Views: 2
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