CVE-2024-42290

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

irqchip/imx-irqsteer: Handle runtime power management correctly

The power domain is automatically activated from clk_prepare(). However, on certain platforms like i.MX8QM and i.MX8QXP, the power-on handling invokes sleeping functions, which triggers the 'scheduling while atomic' bug in the context switch path during device probing:

BUG: scheduling while atomic: kworker/u13:1/48/0x00000002 Call trace: __schedule_bug+0x54/0x6c __schedule+0x7f0/0xa94 schedule+0x5c/0xc4 schedulepreemptdisabled+0x24/0x40 __mutex_lock.constprop.0+0x2c0/0x540 __mutexlockslowpath+0x14/0x20 mutexlock+0x48/0x54 clkpreparelock+0x44/0xa0 clkprepare+0x20/0x44 imxirqsteerresume+0x28/0xe0 pmgenericruntime_resume+0x2c/0x44 __genpdruntimeresume+0x30/0x80 genpdruntimeresume+0xc8/0x2c0 __rpmcallback+0x48/0x1d8 rpmcallback+0x6c/0x78 rpm_resume+0x490/0x6b4 __pmruntimeresume+0x50/0x94 irq_chippmget+0x2c/0xa0 __irqdosethandler+0x178/0x24c irqsetchainedhandleranddata+0x60/0xa4 mxcgpioprobe+0x160/0x4b0

Cure this by implementing the irqbuslock/sync_unlock() interrupt chip callbacks and handle power management in them as they are invoked from non-atomic context.

[ tglx: Rewrote change log, added Fixes tag ]