CVE-2023-52765

In the Linux kernel, the following vulnerability has been resolved: mfd:
qcom-spmi-pmic: Fix revid implementation The Qualcomm SPMI PMIC revid
implementation is broken in multiple ways. First, it assumes that just
because the sibling base device has been registered that means that it is
also bound to a driver, which may not be the case (e.g. due to probe
deferral or asynchronous probe). This could trigger a NULL-pointer
dereference when attempting to access the driver data of the unbound
device. Second, it accesses driver data of a sibling device directly and
without any locking, which means that the driver data may be freed while it
is being accessed (e.g. on driver unbind). Third, it leaks a struct device
reference to the sibling device which is looked up using the
spmi_device_from_of() every time a function (child) device is calling the
revid function (e.g. on probe). Fix this mess by reimplementing the revid
lookup so that it is done only at probe of the PMIC device; the base device
fetches the revid info from the hardware, while any secondary SPMI device
fetches the information from the base device and caches it so that it can
be accessed safely from its children. If the base device has not been
probed yet then probe of a secondary device is deferred.