net: gro: fix outer network offset
Summary
| CVE | CVE-2026-23254 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-18 18:16:23 UTC |
| Updated | 2026-06-01 14:10:37 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: net: gro: fix outer network offset The udp GRO complete stage assumes that all the packets inserted the RX have the `encapsulation` flag zeroed. Such assumption is not true, as a few H/W NICs can set such flag when H/W offloading the checksum for an UDP encapsulated traffic, the tun driver can inject GSO packets with UDP encapsulation and the problematic layout can also be created via a veth based setup. Due to the above, in the problematic scenarios, udp4_gro_complete() uses the wrong network offset (inner instead of outer) to compute the outer UDP header pseudo checksum, leading to csum validation errors later on in packet processing. Address the issue always clearing the encapsulation flag at GRO completion time. Such flag will be set again as needed for encapsulated packets by udp_gro_complete(). |
Risk And Classification
Primary CVSS: v3.1 5.5 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Problem Types: NVD-CWE-noinfo
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected af276a5ac8e938c8b058e3e124073cc1e322d98b 9d40a85138568696387ef04cd004c64612a70874 git | Not specified |
| CNA | Linux | Linux | affected 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 b83557bc6f560433fe5d727e241069f8db5ba709 git | Not specified |
| CNA | Linux | Linux | affected 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 2e5edb69e5d0e23ef248c56fc977039268c77a7b git | Not specified |
| CNA | Linux | Linux | affected 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 5c2c3c38be396257a6a2e55bd601a12bb9781507 git | Not specified |
| CNA | Linux | Linux | affected dbd9466d323a72e22efe09151253d195d36d3bf6 git | Not specified |
| CNA | Linux | Linux | affected 6.6.31 6.6.124 semver | Not specified |
| CNA | Linux | Linux | affected 6.8.10 6.9 semver | Not specified |
| CNA | Linux | Linux | affected 6.9 | Not specified |
| CNA | Linux | Linux | unaffected 6.9 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.124 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.70 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.10 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/2e5edb69e5d0e23ef248c56fc977039268c77a7b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/9d40a85138568696387ef04cd004c64612a70874 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/b83557bc6f560433fe5d727e241069f8db5ba709 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/5c2c3c38be396257a6a2e55bd601a12bb9781507 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.