Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
mmc: sdhci-esdhc-imx: disable irq during suspend to fix unhandled interrupt
When using WIFI out-of-band wakeup, an “irq xxx: nobody cared” warning occurs. This happens because the usdhc interrupt is not disabled during system suspend when device_may_wakeup() returns false.
The sequence of events leading to this issue:
- System enters suspend without disabling usdhc interrupt (because device_may_wakeup() returns false for usdhc device)
- WIFI out-of-band wakeup triggers system resume via GPIO interrupt
- WIFI sends a Card interrupt before usdhc has fully resumed
- usdhc is still in runtime suspend state and cannot handle the interrupt properly
- The unhandled interrupt triggers “nobody cared” warning
Fix this by unconditionally disabling the usdhc interrupt during suspend and re-enabling it during resume, regardless of the wakeup capability. This ensures no interrupts are processed during the suspend/resume transition.
Details
- Affected product:
- Debian 10 ELS
- Affected packages:
- linux @ 4.19.0