CVE-2026-43220

iommu/amd: serialize sequence allocation under concurrent TLB invalidations

MEDIUM
5.5
CVSS Score
Published: May 6, 2026 at 11:28 AM UTC
Updated: October 30, 2026 at 01:18 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.12.75 ≤ v < 6.136.6.128 ≤ v < 6.7496269d12072ecb219826485bdbec70c92a8eef56.12.756.6.128715c263119fd1b918a9fcbd8a36ea5b604a46324d2a0cac10597068567d336e85fa3cbdbe8ca62bfe15768e68820142077bbca402d8e902f64ade1b0f2f65b28d802a667119147444ec2ae33eebf9a58
Vendor states this is fixed in 48caa7542a795c9679ec1bd1bc2592e05a7369a4 (fixed)
Vendor states this is fixed in 5000ce7fcb31067566a1a1a2e5b5bbff93625242 (fixed)
Vendor states this is fixed in 9e249c48412828e807afddc21527eb734dc9bd3d (fixed)
Vendor states this is fixed in d51bf43193b1e95dc4e34e540dc76e19def2ae5a (fixed)
Vendor states this is fixed in fca7aa0264ae99e5ff287d0ced5af0b82b121c4f (fixed)
Affected range stops below 6.12.88, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.6.140, so it looks safe — our inference, not a vendor statement

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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