CVE-2026-74711

Description

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 pmbus_notify(), the code unconditionally casts every attribute to a struct sensor_device_attribute: drivers/hwmon/pmbus/pmbus_core.c:pmbus_notify() { for (i = 0; i < data->num_attributes; i++) { struct device_attribute *da = to_dev_attr(data->group.attrs[i]); struct sensor_device_attribute *attr = to_sensor_dev_attr(da); int index = attr->index; ... } However, data->group.attrs can contain other types like struct pmbus_samples_reg or struct pmbus_sensor, which only embed a base struct device_attribute. If da is a struct pmbus_samples_reg, dev_attr is the last member. Casting it to struct sensor_device_attribute 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 pmbus_sensor, 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 sensor_device_attr in struct pmbus_sensor and struct pmbus_label. 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 products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/ce443f6827b97e03a0fb34ebfddc8939c85e0500 ↗
• https://git.kernel.org/stable/c/1c8dd39d48494cceb2c27c1911cbf26d10ce8514 ↗
• https://git.kernel.org/stable/c/821f6416e69782fa662aff94b5ea52c943042790 ↗
• https://git.kernel.org/stable/c/0b121de89a99c54bcf516999b04e8531c84f08d5 ↗
• https://git.kernel.org/stable/c/59bd68ab05a8f9c9a60b6ec44682084184803ff4 ↗