PT-2026-61272 · Linux · Linux

CVE-2026-63955 · Published 2026-07-19 · Updated 2026-07-19

Mitre

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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().

Fix

Related Identifiers

CVE-2026-63955

Affected Products

Linux

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-63955 · Security Note
• https://git.kernel.org/stable/c/ad7eff07b625f53c3fb513b30d7a8c5a79fbc7ce · Note
• https://git.kernel.org/stable/c/04aa71da5f35aacdc9ae9cb5150947daa624f641 · Note