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

Revert "PCI/MSI: Unmap MSI-X region on error"

This reverts commit 1a8d4c6ecb4c81261bcdf13556abd4a958eca202.

Commit 1a8d4c6ecb4c ("PCI/MSI: Unmap MSI-X region on error") added an
iounmap(dev->msix_base) on the error path of msix_capability_init() to
release the MSI-X region when msix_setup_interrupts() fails.

When msix_setup_interrupts() fails, the call chain is:

msix_setup_interrupts()
-> __msix_setup_interrupts()
struct pci_dev *dev __free(free_msi_irqs) = __dev;
...
return ret; // __free cleanup fires on error

The __free(free_msi_irqs) cleanup calls pci_free_msi_irqs(), which
already handles the unmap:

void pci_free_msi_irqs(struct pci_dev *dev)
{
pci_msi_teardown_msi_irqs(dev);
if (dev->msix_base) {
iounmap(dev->msix_base); // already unmapped here
dev->msix_base = NULL; // and set to NULL
}
}

So dev->msix_base is unmapped and set to NULL before
msix_setup_interrupts() returns to msix_capability_init(). The
"goto out_unmap" introduced by commit 1a8d4c6ecb4c ("PCI/MSI: Unmap
MSI-X region on error") then calls iounmap() a second time on a NULL
pointer.

This was reproduced on Intel Emerald Rapids (192 CPUs) while
running tools/testing/selftests/kexec/test_kexec_jump.sh:

WARNING: CPU#44 at iounmap+0x2a/0xe0
RIP: 0010:iounmap+0x2a/0xe0
RDI: 0000000000000000
Call Trace:
msix_capability_init+0x317/0x3f0
__pci_enable_msix_range+0x21d/0x2c0
pci_alloc_irq_vectors_affinity+0xa9/0x130
nvme_setup_io_queues+0x2a8/0x420 [nvme]
nvme_reset_work+0x151/0x340 [nvme]
...

RDI=0 confirms iounmap() is called with NULL.

Restore the original "goto out_disable" and leave the unmap to the
existing __free(free_msi_irqs) cleanup.
Published: 2026-08-28
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Fri, 28 Aug 2026 07:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: Revert "PCI/MSI: Unmap MSI-X region on error" This reverts commit 1a8d4c6ecb4c81261bcdf13556abd4a958eca202. Commit 1a8d4c6ecb4c ("PCI/MSI: Unmap MSI-X region on error") added an iounmap(dev->msix_base) on the error path of msix_capability_init() to release the MSI-X region when msix_setup_interrupts() fails. When msix_setup_interrupts() fails, the call chain is: msix_setup_interrupts() -> __msix_setup_interrupts() struct pci_dev *dev __free(free_msi_irqs) = __dev; ... return ret; // __free cleanup fires on error The __free(free_msi_irqs) cleanup calls pci_free_msi_irqs(), which already handles the unmap: void pci_free_msi_irqs(struct pci_dev *dev) { pci_msi_teardown_msi_irqs(dev); if (dev->msix_base) { iounmap(dev->msix_base); // already unmapped here dev->msix_base = NULL; // and set to NULL } } So dev->msix_base is unmapped and set to NULL before msix_setup_interrupts() returns to msix_capability_init(). The "goto out_unmap" introduced by commit 1a8d4c6ecb4c ("PCI/MSI: Unmap MSI-X region on error") then calls iounmap() a second time on a NULL pointer. This was reproduced on Intel Emerald Rapids (192 CPUs) while running tools/testing/selftests/kexec/test_kexec_jump.sh: WARNING: CPU#44 at iounmap+0x2a/0xe0 RIP: 0010:iounmap+0x2a/0xe0 RDI: 0000000000000000 Call Trace: msix_capability_init+0x317/0x3f0 __pci_enable_msix_range+0x21d/0x2c0 pci_alloc_irq_vectors_affinity+0xa9/0x130 nvme_setup_io_queues+0x2a8/0x420 [nvme] nvme_reset_work+0x151/0x340 [nvme] ... RDI=0 confirms iounmap() is called with NULL. Restore the original "goto out_disable" and leave the unmap to the existing __free(free_msi_irqs) cleanup.
Title Revert "PCI/MSI: Unmap MSI-X region on error"
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-28T06:48:40.340Z

Reserved: 2026-08-26T14:34:25.774Z

Link: CVE-2026-80620

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-28T08:16:46.083

Modified: 2026-08-28T08:16:46.083

Link: CVE-2026-80620

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-28T10:00:06Z

Weaknesses

No weakness.