What’s Vulnerable › Vulnerabilities

CVE-2026-43220: iommu/amd: serialize sequence allocation under concurrent TLB invalidations

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-06 · updated 2026-10-30

Description

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.

Affected products

• Linux kernel: from 6.6.128 before 6.7; from 6.12.75 before 6.13 — fixed in 6.7, 6.13
• Linux: from 6.1.191 before 6.2 — fixed in 6.2

How to fix

Upgrade to a fixed version: Linux kernel 6.7, 6.13; Linux 6.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/48caa7542a795c9679ec1bd1bc2592e05a7369a4
• https://git.kernel.org/stable/c/5000ce7fcb31067566a1a1a2e5b5bbff93625242
• https://git.kernel.org/stable/c/9e249c48412828e807afddc21527eb734dc9bd3d
• https://git.kernel.org/stable/c/d51bf43193b1e95dc4e34e540dc76e19def2ae5a
• https://git.kernel.org/stable/c/fca7aa0264ae99e5ff287d0ced5af0b82b121c4f

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