On Thu, Mar 07, 2019 at 04:52:20PM +0530, Viresh Kumar wrote:
commit 625c85a62cb7d3c79f6e16de3cfa972033658250 upstream.
The cpufreq_global_kobject is created using kobject_create_and_add() helper, which assigns the kobj_type as dynamic_kobj_ktype and show/store routines are set to kobj_attr_show() and kobj_attr_store().
These routines pass struct kobj_attribute as an argument to the show/store callbacks. But all the cpufreq files created using the cpufreq_global_kobject expect the argument to be of type struct attribute. Things work fine currently as no one accesses the "attr" argument. We may not see issues even if the argument is used, as struct kobj_attribute has struct attribute as its first element and so they will both get same address.
But this is logically incorrect and we should rather use struct kobj_attribute instead of struct global_attr in the cpufreq core and drivers and the show/store callbacks should take struct kobj_attribute as argument instead.
This bug is caught using CFI CLANG builds in android kernel which catches mismatch in function prototypes for such callbacks.
Cc: 4.10 stable@vger.kernel.org # 4.10
Why 4.10? that's a long-dead kernel version :(