From e3b2cf6e5dba416a03152f299d99982dfe1e861d Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 1 Apr 2026 12:15:58 +0200 Subject: kernfs: pass struct ns_common instead of const void * for namespace tags kernfs has historically used const void * to pass around namespace tags used for directory-level namespace filtering. The only current user of this is sysfs network namespace tagging where struct net pointers are cast to void *. Replace all const void * namespace parameters with const struct ns_common * throughout the kernfs, sysfs, and kobject namespace layers. This includes the kobj_ns_type_operations callbacks, kobject_namespace(), and all sysfs/kernfs APIs that accept or return namespace tags. Passing struct ns_common is needed because various codepaths require access to the underlying namespace. A struct ns_common can always be converted back to the concrete namespace type (e.g., struct net) via container_of() or to_ns_common() in the reverse direction. This is a preparatory change for switching to ns_id-based directory iteration to prevent a KASLR pointer leak through the current use of raw namespace pointers as hash seeds and comparison keys. Signed-off-by: Christian Brauner --- include/linux/sysfs.h | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'include/linux/sysfs.h') diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 99b775f3ff46..468259fb6049 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -396,13 +396,13 @@ struct sysfs_ops { #ifdef CONFIG_SYSFS -int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns); +int __must_check sysfs_create_dir_ns(struct kobject *kobj, const struct ns_common *ns); void sysfs_remove_dir(struct kobject *kobj); int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, - const void *new_ns); + const struct ns_common *new_ns); int __must_check sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, - const void *new_ns); + const struct ns_common *new_ns); int __must_check sysfs_create_mount_point(struct kobject *parent_kobj, const char *name); void sysfs_remove_mount_point(struct kobject *parent_kobj, @@ -410,7 +410,7 @@ void sysfs_remove_mount_point(struct kobject *parent_kobj, int __must_check sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, - const void *ns); + const struct ns_common *ns); int __must_check sysfs_create_files(struct kobject *kobj, const struct attribute * const *attr); int __must_check sysfs_chmod_file(struct kobject *kobj, @@ -419,7 +419,7 @@ struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj, const struct attribute *attr); void sysfs_unbreak_active_protection(struct kernfs_node *kn); void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, - const void *ns); + const struct ns_common *ns); bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr); void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attr); @@ -437,7 +437,7 @@ void sysfs_remove_link(struct kobject *kobj, const char *name); int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target, const char *old_name, const char *new_name, - const void *new_ns); + const struct ns_common *new_ns); void sysfs_delete_link(struct kobject *dir, struct kobject *targ, const char *name); @@ -502,7 +502,7 @@ ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj, #else /* CONFIG_SYSFS */ -static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) +static inline int sysfs_create_dir_ns(struct kobject *kobj, const struct ns_common *ns) { return 0; } @@ -512,14 +512,14 @@ static inline void sysfs_remove_dir(struct kobject *kobj) } static inline int sysfs_rename_dir_ns(struct kobject *kobj, - const char *new_name, const void *new_ns) + const char *new_name, const struct ns_common *new_ns) { return 0; } static inline int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, - const void *new_ns) + const struct ns_common *new_ns) { return 0; } @@ -537,7 +537,7 @@ static inline void sysfs_remove_mount_point(struct kobject *parent_kobj, static inline int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, - const void *ns) + const struct ns_common *ns) { return 0; } @@ -567,7 +567,7 @@ static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn) static inline void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, - const void *ns) + const struct ns_common *ns) { } @@ -612,7 +612,7 @@ static inline void sysfs_remove_link(struct kobject *kobj, const char *name) static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t, const char *old_name, - const char *new_name, const void *ns) + const char *new_name, const struct ns_common *ns) { return 0; } -- cgit v1.2.3