CVE-2026-64472: vfio/mlx5: Fix racy bitfields and tighten struct layout
Vulnerability summary
CVE-2026-64472 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.7% of scored vulnerabilities.
No CVSS vector published; no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 27 · Related 25Timeline
- 25-07-2026PublishedVulnerability first disclosed.
- 17-08-2026Last modifiedVulnerability information updated.
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
CVSS metrics
Risk metrics not yet published.
EPSS trend
Probability
0.18%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.18% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: not stated in public data.
Ubuntu142 products
- linuxAll versions (No fix recorded) | < 6.8.0-147.147 | < 7.0.0-31.31
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1067.70 | < 7.0.0-1012.12
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.1.180-1 | < 6.12.100-1 | < 7.1.4-1
- linux-6.12< 6.12.100-1~deb12u1
Linux1 product
- linux≥ 61a2f1460fd03285ea34c1a235f2f50f71e13a1f, < 1dd99b8f4e143592e12e5a77e7b538bc698116cb | ≥ 61a2f1460fd03285ea34c1a235f2f50f71e13a1f, < f1db80a67da928a92ba460ede1be52d8941f46be | ≥ 61a2f1460fd03285ea34c1a235f2f50f71e13a1f, < 399d806f998f7a25405fc1b97227e579aead24af | ≥ 61a2f1460fd03285ea34c1a235f2f50f71e13a1f, < 7ed120b1a007bace57c461805519d70e1af44e59 | ≥ 61a2f1460fd03285ea34c1a235f2f50f71e13a1f, < 39d163627b51886492bf31f66cb02c94613d2287 | ≥ 61a2f1460fd03285ea34c1a235f2f50f71e13a1f, < f2365a63b02ddea32e7db78b742c2503ec7b81f1 | 5.19
3 vendors · 145 products
