[PATCH v3] ACPI: platform-profile: Fix CFI violation when accessing sysfs files

[PATCH v3] ACPI: platform-profile: Fix CFI violation when accessing sysfs files

[Nathan Chancellor]

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 the same type as the callbacks in 'struct kobj_attribute'.

However, the platform_profile sysfs functions have the type of the
->show() and ->store() callbacks in 'struct device_attribute', which
results 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: stable@vger.kernel.org
Fixes: a2ff95e018f1 ("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>
---
Changes in v3:
- Rebase on 6.14-rc1, which includes updates to the driver to address
  Greg's previous concerns but this change is still needed for the
  legacy sysfs interface. v2 can be used for the stable backport.
- Link to v2: https://lore.kernel.org/r/20241118-acpi-platform_profile-fix-cfi-violation-v2-1-62ff952804de@kernel.org

Changes in v2:
- Rebase on linux-pm/acpi
- Pick up Sami's reviewed-by tag
- Adjust wording around why there is no functional issue from the
  mismatched types
- Link to v1: https://lore.kernel.org/r/20240819-acpi-platform_profile-fix-cfi-violation-v1-1-479365d848f6@kernel.org
---
 drivers/acpi/platform_profile.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index fc92e43d0fe9..1b6317f759f9 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -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
 };
 

---
base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
change-id: 20240819-acpi-platform_profile-fix-cfi-violation-de278753bd5f

Best regards,
-- 
Nathan Chancellor <nathan@kernel.org>

Re: [PATCH v3] ACPI: platform-profile: Fix CFI violation when accessing sysfs files

[Greg KH]

On Mon, Feb 10, 2025 at 09:28:25PM -0500, Nathan Chancellor wrote:
> 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 the same type as the callbacks in 'struct kobj_attribute'.
> 
> However, the platform_profile sysfs functions have the type of the
> ->show() and ->store() callbacks in 'struct device_attribute', which
> results 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.

Nice catch.

> Cc: stable@vger.kernel.org
> Fixes: a2ff95e018f1 ("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>
> ---
> Changes in v3:
> - Rebase on 6.14-rc1, which includes updates to the driver to address
>   Greg's previous concerns but this change is still needed for the
>   legacy sysfs interface. v2 can be used for the stable backport.
> - Link to v2: https://lore.kernel.org/r/20241118-acpi-platform_profile-fix-cfi-violation-v2-1-62ff952804de@kernel.org

I'll never find that, so be prepared for a "FAILED" email when this hits
Linus's tree :)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH v3] ACPI: platform-profile: Fix CFI violation when accessing sysfs files

[Mark Pearson]

Hi Nathan

On Mon, Feb 10, 2025, at 9:28 PM, Nathan Chancellor wrote:
> 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 the same type as the callbacks in 'struct kobj_attribute'.
>
> However, the platform_profile sysfs functions have the type of the
> ->show() and ->store() callbacks in 'struct device_attribute', which
> results 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: stable@vger.kernel.org
> Fixes: a2ff95e018f1 ("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>
> ---
> Changes in v3:
> - Rebase on 6.14-rc1, which includes updates to the driver to address
>   Greg's previous concerns but this change is still needed for the
>   legacy sysfs interface. v2 can be used for the stable backport.
> - Link to v2: 
> https://lore.kernel.org/r/20241118-acpi-platform_profile-fix-cfi-violation-v2-1-62ff952804de@kernel.org
>
> Changes in v2:
> - Rebase on linux-pm/acpi
> - Pick up Sami's reviewed-by tag
> - Adjust wording around why there is no functional issue from the
>   mismatched types
> - Link to v1: 
> https://lore.kernel.org/r/20240819-acpi-platform_profile-fix-cfi-violation-v1-1-479365d848f6@kernel.org
> ---
>  drivers/acpi/platform_profile.c | 26 +++++++++++++-------------
>  1 file changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/acpi/platform_profile.c 
> b/drivers/acpi/platform_profile.c
> index fc92e43d0fe9..1b6317f759f9 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -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
>  };
> 
>
> ---
> base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
> change-id: 20240819-acpi-platform_profile-fix-cfi-violation-de278753bd5f
>
> Best regards,
> -- 
> Nathan Chancellor <nathan@kernel.org>

Just a note to say thank you for noticing my email address change - the old lenovo one was awful to use so I dropped it a while back, but it meant I missed your first two patches (my mail filters for the list should have caught it and I'll have to figure out why not...)

From the V1 patch there was a question about why it was done this way: I believe I just copied how it seems to be done everywhere else in the kernel. I can't remember what I used as a reference exactly, but I went and checked a few random drivers and it seems to be everywhere.

Patch looks fine (I'd like to try it out on my system - will aim to do that today). I didn't know what CFI was (and have lightly educated myself now). 
Is there a better way to fix this so it's common across all drivers somehow? Updating every individual instance is going to be a lot.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>

Mark

Re: [PATCH v3] ACPI: platform-profile: Fix CFI violation when accessing sysfs files

[Mark Pearson]

On Tue, Feb 11, 2025, at 10:05 AM, Mark Pearson wrote:
> Hi Nathan
>
> On Mon, Feb 10, 2025, at 9:28 PM, Nathan Chancellor wrote:
>> 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 the same type as the callbacks in 'struct kobj_attribute'.
>>
>> However, the platform_profile sysfs functions have the type of the
>> ->show() and ->store() callbacks in 'struct device_attribute', which
>> results 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: stable@vger.kernel.org
>> Fixes: a2ff95e018f1 ("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>
>> ---
>> Changes in v3:
>> - Rebase on 6.14-rc1, which includes updates to the driver to address
>>   Greg's previous concerns but this change is still needed for the
>>   legacy sysfs interface. v2 can be used for the stable backport.
>> - Link to v2: 
>> https://lore.kernel.org/r/20241118-acpi-platform_profile-fix-cfi-violation-v2-1-62ff952804de@kernel.org
>>
>> Changes in v2:
>> - Rebase on linux-pm/acpi
>> - Pick up Sami's reviewed-by tag
>> - Adjust wording around why there is no functional issue from the
>>   mismatched types
>> - Link to v1: 
>> https://lore.kernel.org/r/20240819-acpi-platform_profile-fix-cfi-violation-v1-1-479365d848f6@kernel.org
>> ---
>>  drivers/acpi/platform_profile.c | 26 +++++++++++++-------------
>>  1 file changed, 13 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/acpi/platform_profile.c 
>> b/drivers/acpi/platform_profile.c
>> index fc92e43d0fe9..1b6317f759f9 100644
>> --- a/drivers/acpi/platform_profile.c
>> +++ b/drivers/acpi/platform_profile.c
>> @@ -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
>>  };
>> 
>>
>> ---
>> base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
>> change-id: 20240819-acpi-platform_profile-fix-cfi-violation-de278753bd5f
>>
>> Best regards,
>> -- 
>> Nathan Chancellor <nathan@kernel.org>
>
> Just a note to say thank you for noticing my email address change - the 
> old lenovo one was awful to use so I dropped it a while back, but it 
> meant I missed your first two patches (my mail filters for the list 
> should have caught it and I'll have to figure out why not...)
>
> From the V1 patch there was a question about why it was done this way: 
> I believe I just copied how it seems to be done everywhere else in the 
> kernel. I can't remember what I used as a reference exactly, but I went 
> and checked a few random drivers and it seems to be everywhere.
>
> Patch looks fine (I'd like to try it out on my system - will aim to do 
> that today). I didn't know what CFI was (and have lightly educated 
> myself now). 
> Is there a better way to fix this so it's common across all drivers 
> somehow? Updating every individual instance is going to be a lot.
>
> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
>
Also:
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>

Mark

Re: [PATCH v3] ACPI: platform-profile: Fix CFI violation when accessing sysfs files

[Nathan Chancellor]

Hi Mark,

On Tue, Feb 11, 2025 at 10:05:18AM -0500, Mark Pearson wrote:
> Just a note to say thank you for noticing my email address change -
> the old lenovo one was awful to use so I dropped it a while back, but
> it meant I missed your first two patches (my mail filters for the list
> should have caught it and I'll have to figure out why not...)

No worries, I totally get that. It may be good to update the few places
in the kernel that still use your Lenovo address but I understand if
there are other reasons to keep it around. .mailmap could also help too.

> Patch looks fine (I'd like to try it out on my system - will aim to do
> that today). I didn't know what CFI was (and have lightly educated
> myself now).  Is there a better way to fix this so it's common across
> all drivers somehow? Updating every individual instance is going to be
> a lot.

This does not happen all too often as far as I can tell. I have only
sent a handful of these patches over the past couple of years since CFI
was officially merged. Due to the way these sysfs interfaces work, I am
not sure this can really be fixed at a grand scale.

Cheers,
Nathan

Re: [PATCH v3] ACPI: platform-profile: Fix CFI violation when accessing sysfs files

[Rafael J. Wysocki]

On Tue, Feb 11, 2025 at 3:28 AM Nathan Chancellor <nathan@kernel.org> wrote:
>
> 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 the same type as the callbacks in 'struct kobj_attribute'.
>
> However, the platform_profile sysfs functions have the type of the
> ->show() and ->store() callbacks in 'struct device_attribute', which
> results 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: stable@vger.kernel.org
> Fixes: a2ff95e018f1 ("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>
> ---
> Changes in v3:
> - Rebase on 6.14-rc1, which includes updates to the driver to address
>   Greg's previous concerns but this change is still needed for the
>   legacy sysfs interface. v2 can be used for the stable backport.
> - Link to v2: https://lore.kernel.org/r/20241118-acpi-platform_profile-fix-cfi-violation-v2-1-62ff952804de@kernel.org
>
> Changes in v2:
> - Rebase on linux-pm/acpi
> - Pick up Sami's reviewed-by tag
> - Adjust wording around why there is no functional issue from the
>   mismatched types
> - Link to v1: https://lore.kernel.org/r/20240819-acpi-platform_profile-fix-cfi-violation-v1-1-479365d848f6@kernel.org
> ---
>  drivers/acpi/platform_profile.c | 26 +++++++++++++-------------
>  1 file changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index fc92e43d0fe9..1b6317f759f9 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -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
>  };
>
>
> ---

Applied as 6.15 material with some edits in the changelog, thanks!