CVE-2026-64472: Linux kernel · vfio/mlx5: Fix racy bitfields and tighten struct layout
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 3 Nov 2026, 18:29 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 3 Nov 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: vfio/mlx5: Fix racy bitfields and tighten struct layout Bitfield operations are not atomic, they use a read-modify-write pattern, therefore we should be careful not to pack bitfields that can be concurrently updated into the same storage unit. This split takes a binary approach: flags that are only modified pre/post open/close remain bitfields, flags modified from user action, including actions that reach across to another device (ex. reset) use dedicated storage units. Note mlx5_vhca_page_tracker.status is relocated to fill the alignment hole this split exposes. Bitfield justifications: migrate_cap: written only in mlx5vf_cmd_set_migratable() at probe chunk_mode: written only in mlx5vf_cmd_set_migratable() at probe mig_state_cap: written only in mlx5vf_cmd_set_migratable() at probe Dedicated storage units: mdev_detach: written in the VF attach/detach event notifier mlx5fv_vf_event() at runtime log_active: written in mlx5vf_start_page_tracker()/ mlx5vf_stop_page_tracker() during runtime dirty tracking deferred_reset: written in mlx5vf_state_mutex_unlock()/ mlx5vf_pci_aer_reset_done() during runtime reset handling is_err: set by tracker error handling and dirty-log polling at runtime object_changed: set by tracker event handling and cleared by dirty-log polling at runtime
References
- git.kernel.org/stable/c/1dd99b8f4e143592e12e5a77e7b538bc698116cb (opens in a new tab)
- git.kernel.org/stable/c/f1db80a67da928a92ba460ede1be52d8941f46be (opens in a new tab)
- git.kernel.org/stable/c/399d806f998f7a25405fc1b97227e579aead24af (opens in a new tab)
- git.kernel.org/stable/c/7ed120b1a007bace57c461805519d70e1af44e59 (opens in a new tab)
- git.kernel.org/stable/c/39d163627b51886492bf31f66cb02c94613d2287 (opens in a new tab)
- git.kernel.org/stable/c/f2365a63b02ddea32e7db78b742c2503ec7b81f1 (opens in a new tab)