mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 04:34:11 +08:00
626ac545c1
When a CONFIG_USER_NS=n and a user tries to unshare some namespace other than the user namespace, the dummy copy_user_ns returns NULL rather than the old_ns. This value then gets assigned to task->nsproxy->user_ns, so that a subsequent setuid, which uses task->nsproxy->user_ns, causes a NULL pointer deref. Fix this by returning old_ns. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
62 lines
1.2 KiB
C
62 lines
1.2 KiB
C
#ifndef _LINUX_USER_NAMESPACE_H
|
|
#define _LINUX_USER_NAMESPACE_H
|
|
|
|
#include <linux/kref.h>
|
|
#include <linux/nsproxy.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/err.h>
|
|
|
|
#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 8)
|
|
#define UIDHASH_SZ (1 << UIDHASH_BITS)
|
|
|
|
struct user_namespace {
|
|
struct kref kref;
|
|
struct list_head uidhash_table[UIDHASH_SZ];
|
|
struct user_struct *root_user;
|
|
};
|
|
|
|
extern struct user_namespace init_user_ns;
|
|
|
|
#ifdef CONFIG_USER_NS
|
|
|
|
static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
|
|
{
|
|
if (ns)
|
|
kref_get(&ns->kref);
|
|
return ns;
|
|
}
|
|
|
|
extern struct user_namespace *copy_user_ns(int flags,
|
|
struct user_namespace *old_ns);
|
|
extern void free_user_ns(struct kref *kref);
|
|
|
|
static inline void put_user_ns(struct user_namespace *ns)
|
|
{
|
|
if (ns)
|
|
kref_put(&ns->kref, free_user_ns);
|
|
}
|
|
|
|
#else
|
|
|
|
static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
|
|
{
|
|
return &init_user_ns;
|
|
}
|
|
|
|
static inline struct user_namespace *copy_user_ns(int flags,
|
|
struct user_namespace *old_ns)
|
|
{
|
|
if (flags & CLONE_NEWUSER)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
return old_ns;
|
|
}
|
|
|
|
static inline void put_user_ns(struct user_namespace *ns)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif /* _LINUX_USER_H */
|