In 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().

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Source ID Title
Ubuntu USN Ubuntu USN USN-8593-1 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 22 Jul 2026 18:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-703

Wed, 22 Jul 2026 00:15:00 +0000


Mon, 20 Jul 2026 14:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Sun, 19 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Description In 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().
Title mm/vmalloc: do not trigger BUG() on BH disabled context
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-20T13:41:53.082Z

Reserved: 2026-07-19T07:54:57.023Z

Link: CVE-2026-63955

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Low

Publid Date: 2026-07-19T00:00:00Z

Links: CVE-2026-63955 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-22T18:30:03Z

Weaknesses