{"id":"AZL-93617","summary":"CVE-2026-64428 affecting package kernel for versions less than 6.6.145.2-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ngpio: sch: use raw_spinlock_t in the irq startup path\n\nsch_irq_unmask() enables the GPIO IRQ and then updates the controller\nstate through sch_irq_mask_unmask(), which takes sch-\u003elock with\nspin_lock_irqsave().  The callback can be reached from irq_startup()\nwhile setting up a requested IRQ.  That path is not sleepable, but on\nPREEMPT_RT a regular spinlock_t becomes a sleeping lock.\n\nThis issue was found by our static analysis tool and then manually\nreviewed against the current tree.\n\nThe grounded PoC kept the request_threaded_irq() -\u003e __setup_irq() -\u003e\nirq_startup() -\u003e sch_irq_unmask() -\u003e sch_irq_mask_unmask() carrier and\nused the original spin_lock_irqsave(&sch-\u003elock) edge.  Lockdep reported:\n\n  BUG: sleeping function called from invalid context\n  hardirqs last disabled at ... __setup_irq.constprop.0 ... [vuln_msv]\n  sch_rt_spin_lock_irqsave+0x1c/0x30 [vuln_msv]\n  sch_irq_mask_unmask.constprop.0+0x31/0x70 [vuln_msv]\n  __setup_irq.constprop.0+0xd/0x30 [vuln_msv]\n\nConvert the SCH controller lock to raw_spinlock_t.  The same lock is\nalso used by the GPIO direction and value callbacks, but those critical\nsections only update MMIO-backed GPIO registers and do not contain\nsleepable operations.  Keeping this register lock non-sleeping is\ntherefore appropriate for the irqchip callbacks and does not change the\nGPIO-side locking contract.","modified":"2026-08-28T17:48:13.026174654Z","published":"2026-07-25T10:17:26Z","upstream":["CVE-2026-64428"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64428"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.145.2-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-93617.json"}}],"schema_version":"1.9.0"}