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ACPI: platform-profile: Fix CFI violation when accessing sysfs files

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When an attribute group is created with sysfs_create_group(), the
->sysfs_ops() callback is set to kobj_sysfs_ops, which sets the ->show()
and ->store() callbacks to kobj_attr_show() and kobj_attr_store()
respectively. These functions use container_of() to get the respective
callback from the passed attribute, meaning that these callbacks need to
be of the same type as the callbacks in 'struct kobj_attribute'.

However, ->show() and ->store() in the platform_profile driver are
defined for struct device_attribute with the help of DEVICE_ATTR_RO()
and DEVICE_ATTR_RW(), which results in a CFI violation when accessing
platform_profile or platform_profile_choices under /sys/firmware/acpi
because the types do not match:

  CFI failure at kobj_attr_show+0x19/0x30 (target: platform_profile_choices_show+0x0/0x140; expected type: 0x7a69590c)

There is no functional issue from the type mismatch because the layout
of 'struct kobj_attribute' and 'struct device_attribute' are the same,
so the container_of() cast does not break anything aside from CFI.

Change the type of platform_profile_choices_show() and
platform_profile_{show,store}() to match the callbacks in
'struct kobj_attribute' and update the attribute variables to
match, which resolves the CFI violation.

Cc: All applicable <stable@vger.kernel.org>
Fixes: a2ff95e018 ("ACPI: platform: Add platform profile support")
Reported-by: John Rowley <lkml@johnrowley.me>
Closes: https://github.com/ClangBuiltLinux/linux/issues/2047
Tested-by: John Rowley <lkml@johnrowley.me>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://patch.msgid.link/20250210-acpi-platform_profile-fix-cfi-violation-v3-1-ed9e9901c33a@kernel.org
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Nathan Chancellor 2025-02-10 21:28:25 -05:00 committed by Rafael J. Wysocki
parent 0ad2507d5d
commit dd4f730b55
1 changed files with 13 additions and 13 deletions
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26
drivers/acpi/platform_profile.c
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@ -260,14 +260,14 @@ static int _aggregate_choices(struct device *dev, void *data)
/**
* platform_profile_choices_show - Show the available profile choices for legacy sysfs interface
* @dev: The device
* @kobj: The kobject
* @attr: The attribute
* @buf: The buffer to write to
*
* Return: The number of bytes written
*/
static ssize_t platform_profile_choices_show(struct device *dev,
struct device_attribute *attr,
static ssize_t platform_profile_choices_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
unsigned long aggregate[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)];
@ -333,14 +333,14 @@ static int _store_and_notify(struct device *dev, void *data)
/**
* platform_profile_show - Show the current profile for legacy sysfs interface
* @dev: The device
* @kobj: The kobject
* @attr: The attribute
* @buf: The buffer to write to
*
* Return: The number of bytes written
*/
static ssize_t platform_profile_show(struct device *dev,
struct device_attribute *attr,
static ssize_t platform_profile_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
@ -362,15 +362,15 @@ static ssize_t platform_profile_show(struct device *dev,
/**
* platform_profile_store - Set the profile for legacy sysfs interface
* @dev: The device
* @kobj: The kobject
* @attr: The attribute
* @buf: The buffer to read from
* @count: The number of bytes to read
*
* Return: The number of bytes read
*/
static ssize_t platform_profile_store(struct device *dev,
struct device_attribute *attr,
static ssize_t platform_profile_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
unsigned long choices[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)];
@ -401,12 +401,12 @@ static ssize_t platform_profile_store(struct device *dev,
return count;
}
static DEVICE_ATTR_RO(platform_profile_choices);
static DEVICE_ATTR_RW(platform_profile);
static struct kobj_attribute attr_platform_profile_choices = __ATTR_RO(platform_profile_choices);
static struct kobj_attribute attr_platform_profile = __ATTR_RW(platform_profile);
static struct attribute *platform_profile_attrs[] = {
&dev_attr_platform_profile_choices.attr,
&dev_attr_platform_profile.attr,
&attr_platform_profile_choices.attr,
&attr_platform_profile.attr,
NULL
};