vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del()
In the Linux kernel, the following vulnerability has been resolved: vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del() vxlan_mdb_is_valid_source(), which validates MDBE_ATTR_SOURCE and every MDBE_ATTR_SRC_LIST member, accepts the all-zeros address. A source list is only accepted on a (*, G) entry, whose source is the all-zeros address, and for each member of the list an (S, G) entry is derived from it by substituting the source. Entries are keyed by a plain memcmp() of struct vxlan_mdb_entry_key, so if MDBE_ATTR_SOURCE is present and holds the all-zeros address and the source list holds it as well, the derived (S, G) key is byte-identical to the (*, G) key and resolves to the same entry. Omitting MDBE_ATTR_SOURCE is not equivalent, as the key is then left with a zero address family. vxlan_mdb_remote_src_del() removes the forwarding entry of a source before freeing the source entry: vxlan_mdb_remote_src_fwd_del(vxlan, group, remote, &ent->addr); vxlan_mdb_remote_src_entry_del(ent); With the keys aliased, the first call deletes the remote of the entry that owns 'ent' instead of a separate (S, G) entry, and frees 'ent'. The second call then runs on the freed entry, and its hlist_del() reads ->pprev and ->next out of it and writes through them. Adding the (*, G) entry with NLM_F_REPLACE and no source list marks the all-zeros source for deletion and reaches this from the sweep at the end of vxlan_mdb_remote_srcs_replace(). BUG: KASAN: slab-use-after-free in __vxlan_mdb_a
CVE-2026-98122
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-2026-98122
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": "a3a48de5eade770e911d35291217bdd69ce04ef1",
"lessThan": "069d5527bb0f229e528fa88c6b72f15060c373f2",
"versionType": "git"
},
{
"status": "affected",
"version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
"lessThan": "e12c903fd13c6261b98ca18d8f70ac26e739e2f8",
"versionType": "git"
},
{
"status": "affected",
"version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
"lessThan": "74e2a56c82209b0335b53e25f19f9b0590e2483d",
"versionType": "git"
},
{
"status": "affected",
"version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
"lessThan": "71203a41d6fa2fa0ea2f3a7541987958bd3694fd",
"versionType": "git"
},
{
"status": "affected",
"version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
"lessThan": "4aa61c88b4e292e10abdfd791334b8272108d68a",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/vxlan/vxlan_mdb.c",
"tools/testing/selftests/net/test_vxlan_mdb.sh"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.4"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.4",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/vxlan/vxlan_mdb.c",
"tools/testing/selftests/net/test_vxlan_mdb.sh"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98122
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #38220 · Revision 1
- Added to Heist Feed
- Publisher date