CVE-2026-74309 PUBLISHED

vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler

Assigner: Linux
Reserved: 15.08.2026 Published: 15.08.2026 Updated: 17.08.2026

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

vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler

Look up the IRQ index in oct_hw->irqs instead of assuming irq - irqs[0]. This supports non-contiguous IRQ numbers and avoids incorrect ring indexing when irqs[0] is not the base.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS Score: 10

AV:N - The bug is in octep_vdpa_intr_handler, entered when the Octeon vDPA virtio-net device raises MSI-X on queue activity; remote or guest-originated network traffic to an internet-facing VM/container backed by this hardware reliably drives that interrupt path on the host. AC:L - Once the vDPA device is active, Linux commonly assigns non-contiguous MSI-X Linux IRQ numbers, so the irq-irqs[0] miscalculation occurs automatically; an attacker only needs to send traffic to generate interrupts without influencing timing or layout. PR:N - Exploitation requires no host credentials: an unauthenticated remote attacker can trigger the handler by sending packets to a virtio-net endpoint already provisioned on Marvell Octeon vDPA hardware, without CAP_NET_ADMIN, root, or vDPA management access. UI:N - No victim interaction is required beyond normal automated network I/O to the exposed virtio-net interface; the attacker does not need the administrator or user to mount devices, click links, or perform any manual action. S:C - In the primary cloud/KVM deployment, guest or remote network traffic crosses the VM/host boundary to corrupt host kernel memory in the vDPA driver interrupt handler, enabling host compromise from tenant or external network reachability rather than staying within the guest security authority. C:H - Incorrect ring indexing can yield negative or out-of-bounds vqs[] indices, causing kernel heap reads via ioread8 on attacker-influenced or adjacent cb_notify_addr pointers and disclosure of surrounding kernel memory contents. I:H - The same out-of-bounds vqs[] access performs iowrite8 acknowledgements to wrong MMIO addresses and may invoke corrupted vqs[i].cb.callback function pointers, providing memory corruption primitives suitable for control-flow hijacking in interrupt context. A:H - Invalid indices lead to bad MMIO accesses and calls through corrupted callback pointers in hardirq context, which can immediately oops or panic the host kernel and deny service to all tenants on the machine.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 26f8ce06af6475b33b0bc60261e9f5027f9af58f to 3ef0cfa77a3d526591be069850d186c255e3f0cc (excl.)
  • affected from 26f8ce06af6475b33b0bc60261e9f5027f9af58f to c6c7eae5de798442987619434171ac886035d57c (excl.)
  • affected from 26f8ce06af6475b33b0bc60261e9f5027f9af58f to 0d21a1d6375a05274291e32c1ab7cd57dbb69513 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.14 is affected
  • unaffected from 0 to 6.14 (excl.)
  • unaffected from 6.18.40 to 6.18.* (incl.)
  • unaffected from 7.1.5 to 7.1.* (incl.)
  • unaffected from 7.2 to * (incl.)

References