{"id":"CVE-2026-74468","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-\u003espinlock with spin_lock_irqsave().  This callback is reached\nfrom __setup_irq() -\u003e __irq_set_trigger() -\u003e chip-\u003eirq_set_type() while\nthe caller holds desc-\u003elock, 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() -\u003e __irq_set_trigger() -\u003e chip-\u003eirq_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\").","modified":"2026-08-21T03:30:40.535284688Z","published":"2026-08-15T12:27:06.250Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74468.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/16da33cb36e663b6967112185e11d00ce8ff957c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/466ab0c41d5f54f71cee60619d07c4abd0ffd2cd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/935e6872db7faecfbe1a10b3f5d97a62fdff5ec9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/98f292cb6d01487d17988d9fd4e19c13e7adb156"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a02b8950d619123da64f69b70fe1dadef217dfe4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c0a4ec89fc26e4b679b04f1002c503cb2529acdc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/efc76a3f5353dd33a2e2ad48200cd4a18de30a0d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ff050589a21967883bb55f6dba42568f8367ad4a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74468.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74468"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"38eb18a6f92da886fc1af509d25e8f7a49e23d9a"},{"fixed":"efc76a3f5353dd33a2e2ad48200cd4a18de30a0d"},{"fixed":"935e6872db7faecfbe1a10b3f5d97a62fdff5ec9"},{"fixed":"98f292cb6d01487d17988d9fd4e19c13e7adb156"},{"fixed":"16da33cb36e663b6967112185e11d00ce8ff957c"},{"fixed":"ff050589a21967883bb55f6dba42568f8367ad4a"},{"fixed":"466ab0c41d5f54f71cee60619d07c4abd0ffd2cd"},{"fixed":"c0a4ec89fc26e4b679b04f1002c503cb2529acdc"},{"fixed":"a02b8950d619123da64f69b70fe1dadef217dfe4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74468.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.2.0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.151"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.103"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.44"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74468.json"}}],"schema_version":"1.9.0"}