CVE-2026-43220: linux kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: serialize sequence allocation under concurrent TLB invalidations With concurrent TLB invalidations, completion wait randomly gets timed out because cmd_sem_val was incremented outside the IOMMU spinlock, allowing CMD_COMPL_WAIT commands to be queued out of sequence and breaking the ordering assumption in wait_on_sem(). Move the cmd_sem_val increment under iommu->lock so completion sequence allocation is serialized with command queuing. And remove the unnecessary return.
CVE-2026-43220CVSS 5.5Linux

CVE-2026-43220: linux kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: serialize sequence allocation under concurrent TLB invalidations With concurrent TLB invalidations, completion wait randomly gets timed out because cmd_sem_val was incremented outside the IOMMU spinlock, allowing CMD_COMPL_WAIT commands to be queued out of sequence and breaking the ordering assumption in wait_on_sem(). Move the cmd_sem_val increment under iommu->lock so completion sequence allocation is serialized with command queuing. And remove the unnecessary return.

CVSS
5.5 MEDIUM
EPSS
2.77%
Known exploited
not in KEV
Product
linux kernel

What is known

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: serialize sequence allocation under concurrent TLB invalidations With concurrent TLB invalidations, completion wait randomly gets timed out because cmd_sem_val was incremented outside the IOMMU spinlock, allowing CMD_COMPL_WAIT commands to be queued out of sequence and breaking the ordering assumption in wait_on_sem(). Move the cmd_sem_val increment under iommu->lock so completion sequence allocation is serialized with command queuing. And remove the unnecessary return.

Sources

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