kernel_optimize_test/fs/mount.h
Kees Cook 3859a271a0 randstruct: Mark various structs for randomization
This marks many critical kernel structures for randomization. These are
structures that have been targeted in the past in security exploits, or
contain functions pointers, pointers to function pointer tables, lists,
workqueues, ref-counters, credentials, permissions, or are otherwise
sensitive. This initial list was extracted from Brad Spengler/PaX Team's
code in the last public patch of grsecurity/PaX based on my understanding
of the code. Changes or omissions from the original code are mine and
don't reflect the original grsecurity/PaX code.

Left out of this list is task_struct, which requires special handling
and will be covered in a subsequent patch.

Signed-off-by: Kees Cook <keescook@chromium.org>
2017-06-30 12:00:51 -07:00

147 lines
3.7 KiB
C

#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/poll.h>
#include <linux/ns_common.h>
#include <linux/fs_pin.h>
struct mnt_namespace {
atomic_t count;
struct ns_common ns;
struct mount * root;
struct list_head list;
struct user_namespace *user_ns;
struct ucounts *ucounts;
u64 seq; /* Sequence number to prevent loops */
wait_queue_head_t poll;
u64 event;
unsigned int mounts; /* # of mounts in the namespace */
unsigned int pending_mounts;
} __randomize_layout;
struct mnt_pcp {
int mnt_count;
int mnt_writers;
};
struct mountpoint {
struct hlist_node m_hash;
struct dentry *m_dentry;
struct hlist_head m_list;
int m_count;
};
struct mount {
struct hlist_node mnt_hash;
struct mount *mnt_parent;
struct dentry *mnt_mountpoint;
struct vfsmount mnt;
union {
struct rcu_head mnt_rcu;
struct llist_node mnt_llist;
};
#ifdef CONFIG_SMP
struct mnt_pcp __percpu *mnt_pcp;
#else
int mnt_count;
int mnt_writers;
#endif
struct list_head mnt_mounts; /* list of children, anchored here */
struct list_head mnt_child; /* and going through their mnt_child */
struct list_head mnt_instance; /* mount instance on sb->s_mounts */
const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
struct list_head mnt_list;
struct list_head mnt_expire; /* link in fs-specific expiry list */
struct list_head mnt_share; /* circular list of shared mounts */
struct list_head mnt_slave_list;/* list of slave mounts */
struct list_head mnt_slave; /* slave list entry */
struct mount *mnt_master; /* slave is on master->mnt_slave_list */
struct mnt_namespace *mnt_ns; /* containing namespace */
struct mountpoint *mnt_mp; /* where is it mounted */
struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
#ifdef CONFIG_FSNOTIFY
struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
__u32 mnt_fsnotify_mask;
#endif
int mnt_id; /* mount identifier */
int mnt_group_id; /* peer group identifier */
int mnt_expiry_mark; /* true if marked for expiry */
struct hlist_head mnt_pins;
struct fs_pin mnt_umount;
struct dentry *mnt_ex_mountpoint;
} __randomize_layout;
#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
static inline struct mount *real_mount(struct vfsmount *mnt)
{
return container_of(mnt, struct mount, mnt);
}
static inline int mnt_has_parent(struct mount *mnt)
{
return mnt != mnt->mnt_parent;
}
static inline int is_mounted(struct vfsmount *mnt)
{
/* neither detached nor internal? */
return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
}
extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
extern int __legitimize_mnt(struct vfsmount *, unsigned);
extern bool legitimize_mnt(struct vfsmount *, unsigned);
static inline bool __path_is_mountpoint(const struct path *path)
{
struct mount *m = __lookup_mnt(path->mnt, path->dentry);
return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
}
extern void __detach_mounts(struct dentry *dentry);
static inline void detach_mounts(struct dentry *dentry)
{
if (!d_mountpoint(dentry))
return;
__detach_mounts(dentry);
}
static inline void get_mnt_ns(struct mnt_namespace *ns)
{
atomic_inc(&ns->count);
}
extern seqlock_t mount_lock;
static inline void lock_mount_hash(void)
{
write_seqlock(&mount_lock);
}
static inline void unlock_mount_hash(void)
{
write_sequnlock(&mount_lock);
}
struct proc_mounts {
struct mnt_namespace *ns;
struct path root;
int (*show)(struct seq_file *, struct vfsmount *);
void *cached_mount;
u64 cached_event;
loff_t cached_index;
};
extern const struct seq_operations mounts_op;
extern bool __is_local_mountpoint(struct dentry *dentry);
static inline bool is_local_mountpoint(struct dentry *dentry)
{
if (!d_mountpoint(dentry))
return false;
return __is_local_mountpoint(dentry);
}