CVE-2026-64254

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

NTB: epf: Avoid pci_iounmap() with offset when PEER_SPAD and CONFIG share BAR

When BAR_PEER_SPAD and BAR_CONFIG share one PCI BAR, the module teardown

path ends up calling pci_iounmap() on the same iomem with some offset,

which is unnecessary and triggers a kernel warning like the following:

Trying to vunmap() nonexistent vm area (0000000069a5ffe8)

WARNING: mm/vmalloc.c:3470 at vunmap+0x58/0x68, CPU#5: modprobe/2937

[...]

Call trace:

vunmap+0x58/0x68 (P)

iounmap+0x34/0x48

pci_iounmap+0x2c/0x40

ntb_epf_pci_remove+0x44/0x80 [ntb_hw_epf]

pci_device_remove+0x48/0xf8

device_remove+0x50/0x88

device_release_driver_internal+0x1c8/0x228

driver_detach+0x50/0xb0

bus_remove_driver+0x74/0x100

driver_unregister+0x34/0x68

pci_unregister_driver+0x34/0xa0

ntb_epf_pci_driver_exit+0x14/0xfe0 [ntb_hw_epf]

[...]

Fix it by unmapping only when PEER_SPAD and CONFIG use difference bars.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References