ghsa-fxr5-v2qf-8828
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
xfrm: state: fix out-of-bounds read during lookup
lookup and resize can run in parallel.
The xfrm_state_hash_generation seqlock ensures a retry, but the hash functions can observe a hmask value that is too large for the new hlist array.
rehash does: rcu_assign_pointer(net->xfrm.state_bydst, ndst) [..] net->xfrm.state_hmask = nhashmask;
While state lookup does: h = xfrm_dst_hash(net, daddr, saddr, tmpl->reqid, encap_family); hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h, bydst) {
This is only safe in case the update to state_bydst is larger than net->xfrm.xfrm_state_hmask (or if the lookup function gets serialized via state spinlock again).
Fix this by prefetching state_hmask and the associated pointers. The xfrm_state_hash_generation seqlock retry will ensure that the pointer and the hmask will be consistent.
The existing helpers, like xfrm_dst_hash(), are now unsafe for RCU side, add lockdep assertions to document that they are only safe for insert side.
xfrm_state_lookup_byaddr() uses the spinlock rather than RCU. AFAICS this is an oversight from back when state lookup was converted to RCU, this lock should be replaced with RCU in a future patch.
{
"affected": [],
"aliases": [
"CVE-2024-57982"
],
"database_specific": {
"cwe_ids": [
"CWE-125"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-27T02:15:11Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: state: fix out-of-bounds read during lookup\n\nlookup and resize can run in parallel.\n\nThe xfrm_state_hash_generation seqlock ensures a retry, but the hash\nfunctions can observe a hmask value that is too large for the new hlist\narray.\n\nrehash does:\n rcu_assign_pointer(net-\u003exfrm.state_bydst, ndst) [..]\n net-\u003exfrm.state_hmask = nhashmask;\n\nWhile state lookup does:\n h = xfrm_dst_hash(net, daddr, saddr, tmpl-\u003ereqid, encap_family);\n hlist_for_each_entry_rcu(x, net-\u003exfrm.state_bydst + h, bydst) {\n\nThis is only safe in case the update to state_bydst is larger than\nnet-\u003exfrm.xfrm_state_hmask (or if the lookup function gets\nserialized via state spinlock again).\n\nFix this by prefetching state_hmask and the associated pointers.\nThe xfrm_state_hash_generation seqlock retry will ensure that the pointer\nand the hmask will be consistent.\n\nThe existing helpers, like xfrm_dst_hash(), are now unsafe for RCU side,\nadd lockdep assertions to document that they are only safe for insert\nside.\n\nxfrm_state_lookup_byaddr() uses the spinlock rather than RCU.\nAFAICS this is an oversight from back when state lookup was converted to\nRCU, this lock should be replaced with RCU in a future patch.",
"id": "GHSA-fxr5-v2qf-8828",
"modified": "2025-03-07T15:31:42Z",
"published": "2025-02-27T03:33:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-57982"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a16871c7832ea6435abb6e0b58289ae7dcb7e4fc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dd4c2a174994238d55ab54da2545543d36f4e0d0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e952837f3ddb0ff726d5b582aa1aad9aa38d024d"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.