In the Linux kernel, the following vulnerability has been resolved:
s390/ap: use generic driver_override infrastructure
When the AP masks are updated via apmask_store() or aqmask_store(),
ap_bus_revise_bindings() is called after ap_attr_mutex has been
released.
This calls __ap_revise_reserved(), which accesses the driver_override
field without holding any lock, racing against a concurrent
driver_override_store() that may free the old string, resulting in a
potential UAF.
Fix this by using the driver-core driver_override infrastructure, which
protects all accesses with an internal spinlock.
Note that unlike most other buses, the AP bus does not check
driver_override in its match() callback; the override is checked in
ap_device_probe() and __ap_revise_reserved() instead.
Also note that we do not enable the driver_override feature of struct
bus_type, as AP - in contrast to most other buses - passes "" to
sysfs_emit() when the driver_override pointer is NULL. Thus, printing
"\n" instead of "(null)\n".
Additionally, AP has a custom counter that is modified in the
corresponding custom driver_override_store().
s390/ap: use generic driver_override infrastructure
When the AP masks are updated via apmask_store() or aqmask_store(),
ap_bus_revise_bindings() is called after ap_attr_mutex has been
released.
This calls __ap_revise_reserved(), which accesses the driver_override
field without holding any lock, racing against a concurrent
driver_override_store() that may free the old string, resulting in a
potential UAF.
Fix this by using the driver-core driver_override infrastructure, which
protects all accesses with an internal spinlock.
Note that unlike most other buses, the AP bus does not check
driver_override in its match() callback; the override is checked in
ap_device_probe() and __ap_revise_reserved() instead.
Also note that we do not enable the driver_override feature of struct
bus_type, as AP - in contrast to most other buses - passes "" to
sysfs_emit() when the driver_override pointer is NULL. Thus, printing
"\n" instead of "(null)\n".
Additionally, AP has a custom counter that is modified in the
corresponding custom driver_override_store().
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
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Fixes
Solution
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Workaround
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References
History
Wed, 24 Jun 2026 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: s390/ap: use generic driver_override infrastructure When the AP masks are updated via apmask_store() or aqmask_store(), ap_bus_revise_bindings() is called after ap_attr_mutex has been released. This calls __ap_revise_reserved(), which accesses the driver_override field without holding any lock, racing against a concurrent driver_override_store() that may free the old string, resulting in a potential UAF. Fix this by using the driver-core driver_override infrastructure, which protects all accesses with an internal spinlock. Note that unlike most other buses, the AP bus does not check driver_override in its match() callback; the override is checked in ap_device_probe() and __ap_revise_reserved() instead. Also note that we do not enable the driver_override feature of struct bus_type, as AP - in contrast to most other buses - passes "" to sysfs_emit() when the driver_override pointer is NULL. Thus, printing "\n" instead of "(null)\n". Additionally, AP has a custom counter that is modified in the corresponding custom driver_override_store(). | |
| Title | s390/ap: use generic driver_override infrastructure | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-06-24T16:30:47.982Z
Reserved: 2026-06-09T07:44:35.385Z
Link: CVE-2026-53116
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses
No weakness.