CVE-2026-72409

Summary

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

net: mvneta: re-enable percpu interrupt on resume

On Marvell MPIC platforms (Armada 370/XP/38x), mvneta uses a percpu IRQ disable/enable scheme for NAPI: the ISR (mvneta_percpu_isr) calls disable_percpu_irq() to mask the MPIC per-CPU interrupt and schedules NAPI poll, which calls enable_percpu_irq() on completion to unmask.

If suspend occurs while NAPI poll is pending (between disable_percpu_irq in the ISR and enable_percpu_irq in poll completion), the interrupt is never re-enabled:

  1. mvneta_percpu_isr: disable_percpu_irq() + napi_schedule() => MPIC masked, percpu_enabled cpumask bit cleared
  2. NAPI poll does not complete before suspend proceeds (on PREEMPT_RT this is highly likely since softirqs run in ksoftirqd which gets frozen; on non-RT it can happen when softirq processing is deferred to ksoftirqd)
  3. mvneta_stop_dev => napi_disable(): cancels the pending poll without executing the completion path
  4. suspend_device_irqs => IRQCHIP_MASK_ON_SUSPEND: masks MPIC (already masked, but records IRQS_SUSPENDED)
  5. Resume: mpic_resume checks irq_percpu_is_enabled() => false (bit was cleared in step 1) => skips unmask
  6. mvneta_start_dev only restores device-level INTR_NEW_MASK, does not touch the MPIC per-CPU mask

Result: MPIC per-CPU interrupt stays masked permanently. The NIC generates interrupts (INTR_NEW_CAUSE != 0) but the CPU never receives them, causing complete loss of network connectivity.

Fix by calling on_each_cpu(mvneta_percpu_enable) in the resume path to unconditionally unmask the MPIC per-CPU interrupt regardless of pre-suspend state.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < bf88cd3b649bc3e638f1e8a77649581852747a68affected
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < 8c7a489aa71d2693752b2e794a68bf672d16c829affected
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < 82c13027ed283b856017adee970dbfdffce5c6b8affected
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < be626ac1faadd49c2cead9f9cd06ba8752d81563affected
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < 1cc312dc8bc78fa24c80d5bc193dbf5b57a99cc6affected
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < b84dd48f9da1eb132bdc06a944423cd5a1641ef1affected
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < 5bdb33ff6e58bdc43632e98b30723eb65352d671affected
LinuxLinux12bb03b436dad56692e9a103ed26156156bef5d2 < fd398d6480987e4c84fff0aaab6b9d6642a93343affected
LinuxLinux4.4affected
LinuxLinux0 < 4.4unaffected
LinuxLinux5.10.261 <= 5.10.*unaffected
LinuxLinux5.15.212 <= 5.15.*unaffected
LinuxLinux6.1.178 <= 6.1.*unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.97 <= 6.12.*unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References