CVE-2026-80620

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.

Affected Software

References

• https://git.kernel.org/stable/c/0a2aeb02894b839ecc3ece6dc7e5c3d6c3def16f
• https://git.kernel.org/stable/c/3691a82be2095abaf3326a1cbf7b25858a1d959c
• https://git.kernel.org/stable/c/6848ca381edff84f87dd1b6973848c271541e813
• https://git.kernel.org/stable/c/82e120a7dd566c476ba923d30e3fb78e8118a1dd
• https://git.kernel.org/stable/c/f64e03da0d83cb173743888bff4a7e61476a8fc2
• https://git.kernel.org/stable/c/f79519f636059b007d6abc91652f36dea4f54a20