In the Linux kernel, the following vulnerability has been resolved:
scsi: pm8001: Use rollback index when freeing MSI-X vectors
pm8001_request_msix() unwinds previously registered handlers with
free_irq() when request_irq() fails. The rollback loop uses the failing
index i for every iteration instead of the already registered vector
index j.
That passes the wrong IRQ/dev_id pair to free_irq() and leaves the
earlier handlers installed. Use j for both pci_irq_vector() and the
matching irq_vector entry in the rollback loop.
CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 7.8
AV:L - The bug is in pm8001_request_msix() on the PCI SAS HBA probe and resume path (pm8001_pci_probe/pm8001_pci_resume → pm8001_alloc/pm8001_request_irq), not in network, FC, or USB packet processing; PMC-Sierra/Microchip/ATTO/Adaptec SPCv controllers are local PCI devices in storage servers and workstations.
AC:L - Once request_irq() fails after any earlier MSI-X vector succeeded, rollback always free_irq()s the failing index i instead of registered index j, then pci_free_irq_vectors() and kfree of the HBA; a local attacker can induce that partial failure with memory or IRQ exhaustion and does not depend on an uncontrolled race.
PR:L - An unprivileged local user on a machine with a multi-vector SPCv pm8001 HBA can apply memory pressure during probe, deferred probe, or resume so a later request_irq() fails, then spray the heap against the leftover IRQ handler; PCI bind/unbind needs init-namespace root but is not required to exploit the planted UAF.
UI:N - No victim must mount a filesystem, open a device, or plug hardware; the attacker induces the MSI-X request failure and consumes the leftover handler without another user's action.
S:U - The leftover irqaction and use-after-free of pm8001_hba_info stay in the host kernel IRQ/SCSI path and do not cross a VM, IOMMU, or other security-authority boundary.
C:H - Failed MSI-X registration leaves pm8001_interrupt_handler_msix installed with dev_id pointing into pm8001_ha, which pm8001_free() then kfree()s, a use-after-free that per kernel CNA guidance enables arbitrary kernel memory disclosure via slab reuse.
I:H - The same dangling MSI-X handler reads irq_vector->drv_inst and invokes isr/tasklet on the freed HBA object; reclaiming that heap allocation yields write and control-flow hijack primitives, so integrity impact is High.
A:H - Wrong-index free_irq() hits WARN on an already-free IRQ, pci_free_irq_vectors() tears down descriptors with live irqactions, and a later IRQ or panic_on_warn can oops or panic the kernel, fully denying availability.
| Attack Vector |
Local |
Scope |
Unchanged |
| Attack Complexity |
Low |
Confidentiality Impact |
High |
| Privileges Required |
Low |
Integrity Impact |
High |
| User Interaction |
None |
Availability Impact |
High |
AV:L - The bug is in pm8001_request_msix() on the PCI SAS HBA probe and resume path (pm8001_pci_probe/pm8001_pci_resume → pm8001_alloc/pm8001_request_irq), not in network, FC, or USB packet processing; PMC-Sierra/Microchip/ATTO/Adaptec SPCv controllers are local PCI devices in storage servers and workstations.
AC:L - Once request_irq() fails after any earlier MSI-X vector succeeded, rollback always free_irq()s the failing index i instead of registered index j, then pci_free_irq_vectors() and kfree of the HBA; a local attacker can induce that partial failure with memory or IRQ exhaustion and does not depend on an uncontrolled race.
PR:L - An unprivileged local user on a machine with a multi-vector SPCv pm8001 HBA can apply memory pressure during probe, deferred probe, or resume so a later request_irq() fails, then spray the heap against the leftover IRQ handler; PCI bind/unbind needs init-namespace root but is not required to exploit the planted UAF.
UI:N - No victim must mount a filesystem, open a device, or plug hardware; the attacker induces the MSI-X request failure and consumes the leftover handler without another user's action.
S:U - The leftover irqaction and use-after-free of pm8001_hba_info stay in the host kernel IRQ/SCSI path and do not cross a VM, IOMMU, or other security-authority boundary.
C:H - Failed MSI-X registration leaves pm8001_interrupt_handler_msix installed with dev_id pointing into pm8001_ha, which pm8001_free() then kfree()s, a use-after-free that per kernel CNA guidance enables arbitrary kernel memory disclosure via slab reuse.
I:H - The same dangling MSI-X handler reads irq_vector->drv_inst and invokes isr/tasklet on the freed HBA object; reclaiming that heap allocation yields write and control-flow hijack primitives, so integrity impact is High.
A:H - Wrong-index free_irq() hits WARN on an already-free IRQ, pci_free_irq_vectors() tears down descriptors with live irqactions, and a later IRQ or panic_on_warn can oops or panic the kernel, fully denying availability.
CVSS 3.1