ip6_gre: remove obsolete ERSPAN PMTU update
In the Linux kernel, the following vulnerability has been resolved: ip6_gre: remove obsolete ERSPAN PMTU update A tc tunnel_key action can attach a METADATA_IP_TUNNEL dst to an skb, and mirred can redirect it to a native ip6erspan device. The legacy PMTU update in ip6erspan_tunnel_xmit() treats that metadata dst as a route. Since it has no output device, dst_dev(dst)->mtu dereferences NULL. On v7.2 with KASAN, an initial UID/GID 65534 process with CapEff 0 used self-created user and network namespaces to trigger: KASAN: null-ptr-deref RIP: ip6erspan_tunnel_xmit+0x10fc/0x2cc0 Kernel panic - not syncing: Fatal exception in interrupt The update is obsolete. Commit fe1a4ca0a2b7 ("ip6_gre: process toobig in a better way") changed IPv6 GRE Too Big handling to update the underlay route and removed the equivalent block from __gre6_xmit(). ip6_tnl_xmit() then propagates the underlay PMTU to the overlay route. Remove the stale ERSPAN copy and its now-unused dst variable. This eliminates the metadata-dst dereference and keeps ERSPAN aligned with IPv6 GRE PMTU handling.
CVE-2026-99041
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-99041
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5a963eb61b7c39e6c422b6e48619d19d04719358",
"lessThan": "b14a682ad7d45345701e08f9279d483a1da8b36c",
"versionType": "git"
},
{
"status": "affected",
"version": "5a963eb61b7c39e6c422b6e48619d19d04719358",
"lessThan": "f5b143f4cd3fb7673df8d727550478a4b762908a",
"versionType": "git"
},
{
"status": "affected",
"version": "5a963eb61b7c39e6c422b6e48619d19d04719358",
"lessThan": "2d06cb25a497d3a7034ef9d172626c2d6620a0f1",
"versionType": "git"
},
{
"status": "affected",
"version": "5a963eb61b7c39e6c422b6e48619d19d04719358",
"lessThan": "8f27260b989f488760289276377db24fbfb20bfa",
"versionType": "git"
},
{
"status": "affected",
"version": "5a963eb61b7c39e6c422b6e48619d19d04719358",
"lessThan": "8bc60db48e8cba35488bbd6e1f94aa990afa275a",
"versionType": "git"
}
],
"programFiles": [
"net/ipv6/ip6_gre.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.58",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.11",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv6/ip6_gre.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-99041
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #52874 · Revision 1
- Added to Heist Feed
- Publisher date