UBUNTU-CVE-2026-74711: High severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus) Fix type confusion in notification logic Sashiko reports: At the start of the loop in pmbusnotify(), the code unconditionally casts every attribute to a struct sensordeviceattribute: drivers/hwmon/pmbus/pmbuscore.c:pmbusnotify() { for (i = 0; i < data->numattributes; i++) { struct deviceattribute da = todevattr(data->group.attrs[i]); struct sensordeviceattribute attr = tosensordevattr(da); int index = attr->index; ... } However, data->group.attrs can contain other types like struct pmbussamplesreg or struct pmbussensor, which only embed a base struct deviceattribute. If da is a struct pmbussamplesreg, devattr is the last member. Casting it to struct sensordeviceattribute and reading the index field appears to access memory past the end of the allocation, which might trigger a slab-out-of-bounds read. Additionally, if da is a struct pmbussensor, casting it causes the index field to overlap with the page, phase, and reg fields. Could this produce a garbage mask on little-endian systems that spuriously matches the target reg, page, and flags during an alert? Fix the problem by using struct sensordeviceattr in struct pmbussensor and struct pmbuslabel. Since those attributes never trigger a notification, set the value of attr->index to -1 for them. Use this value to distinguish from boolean attributes which can trigger a notification and use the index field to encode mask, page, and register values.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1036.39 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Configuration
Use struct sensor_device_attr in struct pmbus_sensor and struct pmbus_label instead of relying on the incompatible struct sensor_device_attribute cast.
Linux kernel hwmon pmbus attribute type in struct pmbus_sensor and struct pmbus_label = struct sensor_device_attr - Configuration
Set attr->index to -1 for attributes that cannot trigger notifications, and use -1 to distinguish them from boolean attributes whose index encodes mask, page, and register values.
Linux kernel hwmon pmbus notification logic attr->index for non-notification attributes = -1