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 --- lib/kobject.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index cfdb2c3f20a2..9c9ff0f5175f 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -27,7 +27,7 @@ * and thus @kobj should have a namespace tag associated with it. Returns * %NULL otherwise. */ -const void *kobject_namespace(const struct kobject *kobj) +const struct ns_common *kobject_namespace(const struct kobject *kobj) { const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj); @@ -1083,9 +1083,9 @@ bool kobj_ns_current_may_mount(enum kobj_ns_type type) return may_mount; } -void *kobj_ns_grab_current(enum kobj_ns_type type) +struct ns_common *kobj_ns_grab_current(enum kobj_ns_type type) { - void *ns = NULL; + struct ns_common *ns = NULL; spin_lock(&kobj_ns_type_lock); if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) @@ -1096,7 +1096,7 @@ void *kobj_ns_grab_current(enum kobj_ns_type type) } EXPORT_SYMBOL_GPL(kobj_ns_grab_current); -void kobj_ns_drop(enum kobj_ns_type type, void *ns) +void kobj_ns_drop(enum kobj_ns_type type, struct ns_common *ns) { spin_lock(&kobj_ns_type_lock); if (kobj_ns_type_is_valid(type) && -- cgit v1.2.3