ACPI: Split out custom_method functionality into an own driver

With /sys/kernel/debug/acpi/custom_method root can write
to arbitrary memory and increase his priveleges, even if
these are restricted.

-> Make this an own debug .config option and warn about the
security issue in the config description.

-> Still keep acpi/debugfs.c which now only creates an empty
   /sys/kernel/debug/acpi directory. There might be other
   users of it later.

Signed-off-by: Thomas Renninger <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: [email protected]
Signed-off-by: Len Brown <[email protected]>
This commit is contained in:
Thomas Renninger 2011-05-26 12:26:24 +02:00 • committed by Len Brown
commit 526b4af47f
5 changed files with 122 additions and 79 deletions

View file

@ -66,3 +66,8 @@ Note: We can use a kernel with multiple custom ACPI method running,
But each individual write to debugfs can implement a SINGLE
method override. i.e. if we want to insert/override multiple
ACPI methods, we need to redo step c) ~ g) for multiple times.
Note: Be aware that root can mis-use this driver to modify arbitrary
memory and gain additional rights, if root's privileges got
restricted (for example if root is not allowed to load additional
modules after boot).