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FAILED: patch "[PATCH] ACPI: platform-profile: Fix CFI violation when accessing" failed to apply to 6.6-stable tree

PATCH [email protected] 1 participant 1 message Apr 8, 2025

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The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x dd4f730b557ce701a2cd4f604bf1e57667bd8b6e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025040804-level-crystal-ca73@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From dd4f730b557ce701a2cd4f604bf1e57667bd8b6e Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <[email protected]>
Date: Mon, 10 Feb 2025 21:28:25 -0500
Subject: [PATCH] ACPI: platform-profile: Fix CFI violation when accessing
sysfs files

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 <[email protected]>
Fixes a2ff95e018f1 ("ACPI: platform: Add platform profile support")
Reported-by John Rowley <[email protected]>
Closes https://github.com/ClangBuiltLinux/linux/issues/2047
Tested-by John Rowley <[email protected]>
Reviewed-by Sami Tolvanen <[email protected]>
Signed-off-by Nathan Chancellor <[email protected]>
Acked-by Greg Kroah-Hartman <[email protected]>
Reviewed-by Mark Pearson <[email protected]>
Tested-by Mark Pearson <[email protected]>
Link https://patch.msgid.link/20250210-acpi-platform_profile-fix-cfi-violation-v3-1-ed9e9901c33a@kernel.org open here
[ rjw: Changelog edits ]
Signed-off-by Rafael J. Wysocki <[email protected]>
drivers/acpi/platform_profile.c +13 -13
index fc92e43d0fe9..1b6317f759f9 100644
@@ -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
 };