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
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
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References
History
Sat, 25 Jul 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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 | |
| Title | vfio/mlx5: Fix racy bitfields and tighten struct layout | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-25T08:51:35.978Z
Reserved: 2026-07-19T15:36:31.790Z
Link: CVE-2026-64472
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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