{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-74468",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-74468"
  ],
  "published": "2026-08-15T12:28:42Z",
  "summary": "gpio: pch: use raw_spinlock_t for the register lock",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ngpio: pch: use raw_spinlock_t for the register lock\n\npch_irq_type() is registered as the irq_chip .irq_set_type callback and\ntakes chip->spinlock with spin_lock_irqsave().  This callback is reached\nfrom __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while\nthe caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled.\nThat context is not sleepable, but on PREEMPT_RT a regular spinlock_t is\nan rtmutex-backed sleeping lock, so acquiring it there is invalid.\n\nThis was confirmed on a PREEMPT_RT kernel with lockdep\n(PROVE_RAW_LOCK_NESTING and DEBUG_ATOMIC_SLEEP).  A grounded PoC mirrored\npch_irq_type()'s locking and drove it through the real genirq carrier\nirq_set_irq_type() -> __irq_set_trigger() -> chip->irq_set_type(), i.e.\nthe same __irq_set_trigger() edge that __setup_irq() takes for a\nrequested IRQ.  With the original spin_lock_irqsave() edge lockdep\nreported an invalid wait context, immediately followed by:\n\n  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48\n  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 95, name: insmod\n  hardirqs last disabled at (3784): _raw_spin_lock_irqsave+0x4f/0x60\n   rt_spin_lock+0x3a/0x1c0\n   repro_irq_set_type+0x64/0xa0 [pch_repro]\n   __irq_set_trigger+0x69/0x140\n   irq_set_irq_type+0x78/0xd0\n\nSwitching the mirrored lock to raw_spinlock_t made both splats go away.\n\nConvert the register lock to raw_spinlock_t.  The same lock also\nserializes the GPIO direction/value callbacks and the suspend/resume\nregister save/restore, but all of those critical sections only perform\nMMIO register accesses (ioread32()/iowrite32()) and\nirq_set_handler_locked(); none of them contain sleepable operations.\nKeeping this register lock non-sleeping is therefore appropriate for the\nirqchip callbacks and does not change the GPIO-side locking contract.\n\nThis is the same class of issue and fix as recently addressed for other\nGPIO controllers, e.g. commit 286533cb14a3 (\"gpio: sch: use raw_spinlock_t\nin the irq startup path\") and commit 90f0109019e6 (\"gpio: eic-sprd: use\nraw_spinlock_t in the irq startup path\").",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.183",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-74468"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/efc76a3f5353dd33a2e2ad48200cd4a18de30a0d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/935e6872db7faecfbe1a10b3f5d97a62fdff5ec9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/98f292cb6d01487d17988d9fd4e19c13e7adb156"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/16da33cb36e663b6967112185e11d00ce8ff957c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ff050589a21967883bb55f6dba42568f8367ad4a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/466ab0c41d5f54f71cee60619d07c4abd0ffd2cd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c0a4ec89fc26e4b679b04f1002c503cb2529acdc"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a02b8950d619123da64f69b70fe1dadef217dfe4"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-19T16:47:12Z"
  }
}