GHSA-WQFP-WXF7-9VR7
Vulnerability from github – Published: 2025-09-17 15:30 – Updated: 2025-12-11 18:30In the Linux kernel, the following vulnerability has been resolved:
lwt: Fix return values of BPF xmit ops
BPF encap ops can return different types of positive values, such like NET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function skb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return values would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in ip(6)_finish_output2. When this happens, skbs that have been freed would continue to the neighbor subsystem, causing use-after-free bug and kernel crashes.
To fix the incorrect behavior, skb_do_redirect return values can be simply discarded, the same as tc-egress behavior. On the other hand, bpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU information. Thus convert its return values to avoid the conflict with LWTUNNEL_XMIT_CONTINUE.
{
"affected": [],
"aliases": [
"CVE-2023-53338"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-17T15:15:36Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nlwt: Fix return values of BPF xmit ops\n\nBPF encap ops can return different types of positive values, such like\nNET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function\nskb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return\nvalues would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in\nip(6)_finish_output2. When this happens, skbs that have been freed would\ncontinue to the neighbor subsystem, causing use-after-free bug and\nkernel crashes.\n\nTo fix the incorrect behavior, skb_do_redirect return values can be\nsimply discarded, the same as tc-egress behavior. On the other hand,\nbpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU\ninformation. Thus convert its return values to avoid the conflict with\nLWTUNNEL_XMIT_CONTINUE.",
"id": "GHSA-wqfp-wxf7-9vr7",
"modified": "2025-12-11T18:30:32Z",
"published": "2025-09-17T15:30:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-53338"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/065d5f17096ec9161180e2c890afdff4dc6125f2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/29b22badb7a84b783e3a4fffca16f7768fb31205"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/65583f9e070db7bece20710cfa2e3daeb0b831d9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/67f8f2bae8e7ac72e09def2b667e44704c4d1ee1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a97f221651fcdc891166e9bc270e3d9bfa5a0080"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d68c17402442f5f494a2c3ebde5cb82f6aa9160a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e3f647e4b642f9f6d32795a16f92c116c138d2af"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.