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/kobject_ns.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'include/linux/kobject_ns.h') diff --git a/include/linux/kobject_ns.h b/include/linux/kobject_ns.h index 150fe2ae1b6b..4f0990e09b93 100644 --- a/include/linux/kobject_ns.h +++ b/include/linux/kobject_ns.h @@ -16,6 +16,7 @@ #ifndef _LINUX_KOBJECT_NS_H #define _LINUX_KOBJECT_NS_H +struct ns_common; struct sock; struct kobject; @@ -39,10 +40,10 @@ enum kobj_ns_type { struct kobj_ns_type_operations { enum kobj_ns_type type; bool (*current_may_mount)(void); - void *(*grab_current_ns)(void); - const void *(*netlink_ns)(struct sock *sk); - const void *(*initial_ns)(void); - void (*drop_ns)(void *); + struct ns_common *(*grab_current_ns)(void); + const struct ns_common *(*netlink_ns)(struct sock *sk); + const struct ns_common *(*initial_ns)(void); + void (*drop_ns)(struct ns_common *); }; int kobj_ns_type_register(const struct kobj_ns_type_operations *ops); @@ -51,7 +52,7 @@ const struct kobj_ns_type_operations *kobj_child_ns_ops(const struct kobject *pa const struct kobj_ns_type_operations *kobj_ns_ops(const struct kobject *kobj); bool kobj_ns_current_may_mount(enum kobj_ns_type type); -void *kobj_ns_grab_current(enum kobj_ns_type type); -void kobj_ns_drop(enum kobj_ns_type type, void *ns); +struct ns_common *kobj_ns_grab_current(enum kobj_ns_type type); +void kobj_ns_drop(enum kobj_ns_type type, struct ns_common *ns); #endif /* _LINUX_KOBJECT_NS_H */ -- cgit v1.2.3