NTB EPF PCI BAR Unmapping Offsets CVE-2026-64254
CVE-2026-64254 Published on July 24, 2026
NTB: epf: Avoid pci_iounmap() with offset when PEER_SPAD and CONFIG share BAR
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.
Products Associated with CVE-2026-64254
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Affected Versions
Linux:- Version e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 and below eb47b9bffd07a47b84910847cb5ea066ce184055 is affected.
- Version e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 and below 06f6dd2ff2bd07eaf7178a807407ff27e85122b4 is affected.
- Version e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 and below a4be4a1308f02bff79a30eea2d04ead5b63685f2 is affected.
- Version e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 and below 81371dbd23601f67f01372817fdbab42c5601e43 is affected.
- Version e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 and below 9764a786ba98db58f0725913c369e721253aba33 is affected.
- Version e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 and below d876153680e3d721d385e554def919bce3d18c74 is affected.
- Version 6.0 is affected.
- Before 6.0 is unaffected.
- Version 6.1.177, <= 6.1.* is unaffected.
- Version 6.6.144, <= 6.6.* is unaffected.
- Version 6.12.95, <= 6.12.* is unaffected.
- Version 6.18.38, <= 6.18.* is unaffected.
- Version 7.1.3, <= 7.1.* is unaffected.
- Version 7.2-rc1, <= * is unaffected.