High · published May 6, 2026
In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: move wait_on_sem() out of spinlock
With iommu.strict=1, the existing completion wait path can cause soft
lockups under stressed environment, as wait_on_sem() busy-waits under the
spinlock with interrupts disabled.
Move the completion wait in iommu_completion_wait() out of the spinlock.
wait_on_sem() only polls the hardware-updated cmd_sem and does not require
iommu->lock, so holding the lock during the busy wait unnecessarily
increases contention and extends the time with interrupts disabled.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 4.9, < 6.6.128 | 6.6.128 |
| linux/linux_kernel | ≥ 6.7, < 6.12.75 | 6.12.75 |
| linux/linux_kernel | ≥ 6.13, < 6.18.16 | 6.18.16 |
| linux/linux_kernel | ≥ 6.19, < 6.19.6 | 6.19.6 |