Riskcovery

CVE-2026-89562

ip6_gre: fix hardware header length for NBMA tunnels

State
Published
Severity
7.8 High
Published
Sep 11, 2026
Updated
Oct 19, 2026
Reserved
Sep 11, 2026

Read the record on cve.org

Description

In the Linux kernel, the following vulnerability has been resolved:

ip6_gre: fix hardware header length for NBMA tunnels

ip6gre_tnl_link_config_route() accumulates the lower device's hardware header length into dev->hard_header_len whenever header_ops is set. This is incorrect for both users of header_ops.

ip6gretap and ip6erspan have a fixed Ethernet hardware header length. For an NBMA ip6gre tunnel, ip6gre_header() creates only the GRE header, the optional FOU or GUE header, and the outer IPv6 header. The lower device header is headroom needed later, not part of the tunnel device's hardware header.

Keep the lower device header in needed_headroom. Set hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, and leave the fixed Ethernet header length unchanged for tap and erspan devices.

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before cb1afd087aedc90e5274537e4fb9bf3f98e5afdbAffected
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before 7719f6e7ed2ffddc2c3bb61f4467b76d49e0af6aAffected
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before b1e95e3602d8e112458627f14c6c31c21f2188cbAffected
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before c3457a5aae5fb43f7023d3f3dc472c2afa22acf0Affected
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before 8bfe746afee38dd6e4348ddcd22d554789dbb9ffAffected
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before b8282668d8fa7c61b80e8e4890729031c291a16cAffected
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before 565038b0092f65afe384961c0f548d605bf438b9Affected
  • 832ba596494b2c9eac7760259eff2d8b7dcad0ee to before 505b6d296c486ef7d1274f279d4c43a172f63224Affected
  • cf3d9717a5271573fa193c4dfa0df856295d5b15Affected
  • 187a6daf5db45adc807c85bbe285319107bed198Affected
  • d9897bb66ce989325b4bf4cdbb6a799e4ac878b6Affected
  • 4.19.162 to before 4.20Affected
  • 5.4.82 to before 5.5Affected
  • 5.9.13 to before 5.10Affected
LinuxLinux
  • 5.10Affected
  • before 5.10Not affected
  • 5.10.270 through 5.10.*Not affected
  • 5.15.221 through 5.15.*Not affected
  • 6.1.188 through 6.1.*Not affected
  • 6.6.157 through 6.6.*Not affected
  • 6.12.109 through 6.12.*Not affected
  • 6.18.50 through 6.18.*Not affected
  • 7.2.4 through 7.2.*Not affected
  • 7.3 and laterNot affected

References

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