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VulnerabilityPublished Updated

CVE-2026-68329: Linux kernel · Race Condition

Source GCVE Database

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Authoritative record:CVE-2026-68329· High 8.8

Not known to be exploited · CVSS 8.8 High · fixed in d053eb7e09e10cbdca3fca8b35c1017d438091b2 : patch Linux kernel soon.

Data as of 30 Oct 2026, 16:33 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (Linux)CVSS 3.18.8
Patch
Available – fixed in d053eb7e09e10cbdca3fca8b35c1017d438091b2, ab7faf5a172ebfdc423ebb3eea4d472740de82f9, 93494bd446396c257fb589f59894577e96e406e2 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 815b33fdc279d34ab40a8bfe1866623a4cc5669b, < d053eb7e09e10cbdca3fca8b35c1017d438091b2
Fixed in
  • d053eb7e09e10cbdca3fca8b35c1017d438091b2
LinuxLinuxAffected
  • ≥ 815b33fdc279d34ab40a8bfe1866623a4cc5669b, < ab7faf5a172ebfdc423ebb3eea4d472740de82f9
Fixed in
  • ab7faf5a172ebfdc423ebb3eea4d472740de82f9
LinuxLinuxAffected
  • ≥ 815b33fdc279d34ab40a8bfe1866623a4cc5669b, < 93494bd446396c257fb589f59894577e96e406e2
Fixed in
  • 93494bd446396c257fb589f59894577e96e406e2
LinuxLinuxAffected
  • ≥ 815b33fdc279d34ab40a8bfe1866623a4cc5669b, < 82c9a749d44efaaa1a1c781f8a6cf1747718f228
Fixed in
  • 82c9a749d44efaaa1a1c781f8a6cf1747718f228
LinuxLinuxAffected
  • ≥ 815b33fdc279d34ab40a8bfe1866623a4cc5669b, < 02f8cefa2ad95ea3754f0cfd6fbae7f866202ccb
Fixed in
  • 02f8cefa2ad95ea3754f0cfd6fbae7f866202ccb
LinuxLinuxAffected
  • ≥ 815b33fdc279d34ab40a8bfe1866623a4cc5669b, < 1e75a8255f11c81fb07e81e5029cfd75804350a0
Fixed in
  • 1e75a8255f11c81fb07e81e5029cfd75804350a0

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Wait for completion instead of returning early in iommu_completion_wait() need_sync is a per-IOMMU flag shared by all domains and devices behind that IOMMU. It is set whenever a command is queued with sync == true and cleared when a completion-wait (CWAIT) command is queued. However, a cleared need_sync only means that a covering CWAIT has been queued, not that all previously queued commands have actually completed in hardware. iommu_completion_wait() read need_sync locklessly and returned early when it was false. This breaks the "block until all previously queued commands have completed" contract in a multi-CPU scenario: CPU2: queue inv-B => need_sync = true CPU1: queue CWAIT(N); need_sync = false; then wait_on_sem(N) CPU2: read need_sync == false => return 0 (no wait!) CPU2 returns without waiting for any sequence number even though its inv-B may not have completed yet (CWAIT(N), queued after inv-B, has not been signaled). CPU2 then proceeds to, for example, free page-table pages while the IOMMU can still walk stale translations, opening a use-after-free window. This is a logical race in the meaning of the flag, not a memory-visibility issue, so barriers alone do not help. Fix it without losing the optimization of avoiding redundant CWAIT commands: take iommu->lock before testing need_sync, and when it is false do not return early but wait for the last allocated sequence number (cmd_sem_val). Since need_sync == false implies no sync command was queued after the last CWAIT, that CWAIT is FIFO-ordered after every not-yet-completed command, so waiting for its sequence number guarantees all prior commands (possibly queued by another CPU) have completed. The common path with pending work is unchanged and no extra hardware command is issued.

References

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