CVE-2026-98946

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Disable the V3D interrupt across runtime suspend vc4_irq_disable() masks the V3D interrupt sources and then calls synchronize_irq() before the V3D is powered down. However, by itself, this is not enough to quiesce the interrupt handler. synchronize_irq() waits for handlers that have already set IRQD_IRQ_INPROGRESS, and for irqchips reporting IRQCHIP_STATE_ACTIVE. A GIC interrupt chip is able to mark an interrupt active as soon as a CPU acknowledges it, so there these checks cover the whole dispatch path. On RPi 0-3, however, the interrupt controller is ARMCTRL, which has no active state. A CPU that has read the hwirq out of the pending register but has not yet reached handle_level_irq() stays invisible to synchronize_irq(). During a power transition, vc4_irq() may therefore run after the power domain is off, where every V3D register read will return 0xdeadbeef. 0xdeadbeef has FLDONE, FRDONE and OUTOMEM set. This problem doesn't trigger NULL pointer dereference issues only because the functions vc4_irq_finish_bin_job() and vc4_irq_finish_render_job() return early when there is no job pointer, but OUTOMEM is still able to schedule vc4_overflow_mem_work() after vc4_irq_disable() has already cancelled it. Therefore, fix the spurious interrupts by disabling the interrupt line across the PM transition. To preserve the enable/disable balance, move vc4_irq_install() and request the IRQ line disabled before the first runtime resume.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-23 13:17:15.650000

Last modified

2026-10-23 13:17:15.650000

View original CVE JSON

{
  "id": "CVE-2026-98946",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T13:17:15.650",
  "lastModified": "2026-10-23T13:17:15.650",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/vc4: Disable the V3D interrupt across runtime suspend\n\nvc4_irq_disable() masks the V3D interrupt sources and then calls\nsynchronize_irq() before the V3D is powered down. However, by itself,\nthis is not enough to quiesce the interrupt handler.\n\nsynchronize_irq() waits for handlers that have already set\nIRQD_IRQ_INPROGRESS, and for irqchips reporting IRQCHIP_STATE_ACTIVE.\nA GIC interrupt chip is able to mark an interrupt active as soon as a\nCPU acknowledges it, so there these checks cover the whole dispatch path.\nOn RPi 0-3, however, the interrupt controller is ARMCTRL, which has no\nactive state. A CPU that has read the hwirq out of the pending register\nbut has not yet reached handle_level_irq() stays invisible to\nsynchronize_irq().\n\nDuring a power transition, vc4_irq() may therefore run after the power\ndomain is off, where every V3D register read will return 0xdeadbeef.\n0xdeadbeef has FLDONE, FRDONE and OUTOMEM set. This problem doesn't\ntrigger NULL pointer dereference issues only because the functions\nvc4_irq_finish_bin_job() and vc4_irq_finish_render_job() return early\nwhen there is no job pointer, but OUTOMEM is still able to schedule\nvc4_overflow_mem_work() after vc4_irq_disable() has already cancelled it.\n\nTherefore, fix the spurious interrupts by disabling the interrupt line\nacross the PM transition. To preserve the enable/disable balance, move\nvc4_irq_install() and request the IRQ line disabled before the first\nruntime resume."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/gpu/drm/vc4/vc4_irq.c",
            "drivers/gpu/drm/vc4/vc4_v3d.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "9b6f461582e6b07e2ce93227a3e4661846e594ad",
              "lessThan": "e81402c3d42041356cb7978510ebab997bc8d411",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "9b6f461582e6b07e2ce93227a3e4661846e594ad",
              "lessThan": "6abc8e4dcfbc1d26a94c0ac037dfb3716f686b1f",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/gpu/drm/vc4/vc4_irq.c",
            "drivers/gpu/drm/vc4/vc4_v3d.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.1",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.1",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.11",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/6abc8e4dcfbc1d26a94c0ac037dfb3716f686b1f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e81402c3d42041356cb7978510ebab997bc8d411",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}