[ Upstream commit 2bc6262c6117dd18106d5aa50d53e945b5d99c51 ]
All of the CPPC sysfs show functions are called via indirect call in
kobj_attr_show(), where they should be of type
ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, char *buf);
because that is the type of the ->show() member in
'struct kobj_attribute' but they are actually of type
ssize_t (*show)(struct kobject *kobj, struct attribute *attr, char *buf);
because of the ->show() member in 'struct cppc_attr', resulting in a
Control Flow Integrity violation [1].
$ cat /sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf
3400
$ dmesg | grep "CFI failure"
[ 175.970559] CFI failure (target: show_highest_perf+0x0/0x8):
As far as I can tell, the only difference between 'struct cppc_attr'
and 'struct kobj_attribute' aside from the type of the attr parameter
is the type of the count parameter in the ->store() member (ssize_t vs.
size_t), which does not actually matter because all of these nodes are
read-only.
Eliminate 'struct cppc_attr' in favor of 'struct kobj_attribute' to fix
the violation.
[1]: https://lore.kernel.org/r/20210401233216.2540591-1-samitolvanen@google.com/
Fixes: 158c998ea44b ("ACPI / CPPC: add sysfs support to compute delivered performance")
Link: https://github.com/ClangBuiltLinux/linux/issues/1343
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4d8be4bc94f74bb7d096e1c2e44457b530d5a170 upstream.
kobject_init_and_add() takes reference even when it fails.
If this function returns an error, kobject_put() must be called to
properly clean up the memory associated with the object. Previous
commit "b8eb718348b8" fixed a similar problem.
Fixes: 158c998ea44b ("ACPI / CPPC: add sysfs support to compute delivered performance")
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nathan Chancellor