GHSA-JVRV-JPH4-C9C9
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31In the Linux kernel, the following vulnerability has been resolved:
mm/vmalloc: do not trigger BUG() on BH disabled context
__get_vm_area_node() currently triggers a BUG() if in_interrupt() returns true. However, in_interrupt() also reports true when BH are disabled.
The bridge code can call rhashtable_lookup_insert_fast() with bottom halves disabled:
__vlan_add() -> br_fdb_add_local() spin_lock_bh(&br->hash_lock); <-- Disable BH -> fdb_add_local() -> fdb_create() -> rhashtable_lookup_insert_fast() -> kvmalloc() -> vmalloc() -> __get_vm_area_node() -> BUG_ON(in_interrupt()) spin_unlock_bh(&br->hash_lock)
this triggers the BUG() despite the caller not being in NMI or hard IRQ context.
Replace the in_interrupt() check with in_nmi() || in_hardirq().
{
"affected": [],
"aliases": [
"CVE-2026-63955"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:14Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/vmalloc: do not trigger BUG() on BH disabled context\n\n__get_vm_area_node() currently triggers a BUG() if in_interrupt() returns\ntrue. However, in_interrupt() also reports true when BH are disabled.\n\nThe bridge code can call rhashtable_lookup_insert_fast() with bottom\nhalves disabled:\n\n__vlan_add()\n -\u003e br_fdb_add_local()\n spin_lock_bh(\u0026br-\u003ehash_lock); \u003c-- Disable BH\n -\u003e fdb_add_local()\n -\u003e fdb_create()\n -\u003e rhashtable_lookup_insert_fast()\n -\u003e kvmalloc()\n -\u003e vmalloc()\n -\u003e __get_vm_area_node()\n -\u003e BUG_ON(in_interrupt())\n spin_unlock_bh(\u0026br-\u003ehash_lock)\n\nthis triggers the BUG() despite the caller not being in NMI or\nhard IRQ context.\n\nReplace the in_interrupt() check with in_nmi() || in_hardirq().",
"id": "GHSA-jvrv-jph4-c9c9",
"modified": "2026-07-20T15:31:53Z",
"published": "2026-07-19T18:31:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63955"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/04aa71da5f35aacdc9ae9cb5150947daa624f641"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ad7eff07b625f53c3fb513b30d7a8c5a79fbc7ce"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.