CVE-2026-64602: iio: adc: spear: Initialize completion before requesting IRQ

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

iio: adc: spear: Initialize completion before requesting IRQ

In the report from Jaeyoung Chung:

"spearadcprobe() in drivers/iio/adc/spearadc.c registers its interrupt handler with devmrequestirq() before it initializes st->completion with initcompletion(). If an interrupt arrives after devmrequestirq() and before initcompletion(), the handler calls complete() on an uninitialized completion, causing a kernel panic.

The probe path, in spearadcprobe():

iodev = devmiiodevicealloc(&pdev->dev, sizeof(st)); / st kzalloc-zeroed / ... retval = devmrequestirq(&pdev->dev, irq, spearadcisr, 0, LPC32XXADNAME, st); / register handler / ... initcompletion(&st->completion); / initialize completion /

spearadcisr() calls complete():

complete(&st->completion);

If the device raises an interrupt before initcompletion() runs, complete() acquires the uninitialized wait.lock and walks the zeroed tasklist in swakeuplocked(). The zeroed tasklist makes listempty() return false, so swakeuplocked() dereferences a NULL list entry, triggering a KASAN wild-memory-access."

Fix the chance of a spurious IRQ causing an uninitialized pointer dereference by moving initcompletion() above devmrequestirq().