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Merge branch 'audit.b43' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current

Browse source 
* 'audit.b43' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  [PATCH] audit: watching subtrees
  [PATCH] new helper - inotify_evict_watch()
  [PATCH] new helper - inotify_clone_watch()
  [PATCH] new helpers - collect_mounts() and release_collected_mounts()
  [PATCH] pass dentry to audit_inode()/audit_inode_child()
This commit is contained in:
Linus Torvalds 2007-10-21 08:54:32 -07:00
commit 2fb59d623a
21 changed files with 1411 additions and 40 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
fs/dcache.c
View file

@ -38,7 +38,7 @@ int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
static __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
EXPORT_SYMBOL(dcache_lock);

2
fs/debugfs/inode.c
View file

@ -413,7 +413,7 @@ struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
d_move(old_dentry, dentry);
fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name,
old_dentry->d_name.name, S_ISDIR(old_dentry->d_inode->i_mode),
NULL, old_dentry->d_inode);
NULL, old_dentry);
fsnotify_oldname_free(old_name);
unlock_rename(new_dir, old_dir);
dput(dentry);

43
fs/inotify.c
View file

@ -666,6 +666,49 @@ s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch,
}
EXPORT_SYMBOL_GPL(inotify_add_watch);
/**
* inotify_clone_watch - put the watch next to existing one
* @old: already installed watch
* @new: new watch
*
* Caller must hold the inotify_mutex of inode we are dealing with;
* it is expected to remove the old watch before unlocking the inode.
*/
s32 inotify_clone_watch(struct inotify_watch *old, struct inotify_watch *new)
{
struct inotify_handle *ih = old->ih;
int ret = 0;
new->mask = old->mask;
new->ih = ih;
mutex_lock(&ih->mutex);
/* Initialize a new watch */
ret = inotify_handle_get_wd(ih, new);
if (unlikely(ret))
goto out;
ret = new->wd;
get_inotify_handle(ih);
new->inode = igrab(old->inode);
list_add(&new->h_list, &ih->watches);
list_add(&new->i_list, &old->inode->inotify_watches);
out:
mutex_unlock(&ih->mutex);
return ret;
}
void inotify_evict_watch(struct inotify_watch *watch)
{
get_inotify_watch(watch);
mutex_lock(&watch->ih->mutex);
inotify_remove_watch_locked(watch->ih, watch);
mutex_unlock(&watch->ih->mutex);
}
/**
* inotify_rm_wd - remove a watch from an inotify instance
* @ih: inotify handle

10
fs/namei.c
View file

@ -1174,7 +1174,7 @@ static int fastcall do_path_lookup(int dfd, const char *name,
out:
if (unlikely(!retval && !audit_dummy_context() && nd->dentry &&
nd->dentry->d_inode))
audit_inode(name, nd->dentry->d_inode);
audit_inode(name, nd->dentry);
out_fail:
return retval;
@ -1214,7 +1214,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
retval = path_walk(name, nd);
if (unlikely(!retval && !audit_dummy_context() && nd->dentry &&
nd->dentry->d_inode))
audit_inode(name, nd->dentry->d_inode);
audit_inode(name, nd->dentry);
return retval;
@ -1469,7 +1469,7 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir)
return -ENOENT;
BUG_ON(victim->d_parent->d_inode != dir);
audit_inode_child(victim->d_name.name, victim->d_inode, dir);
audit_inode_child(victim->d_name.name, victim, dir);
error = permission(dir,MAY_WRITE | MAY_EXEC, NULL);
if (error)
@ -1783,7 +1783,7 @@ int open_namei(int dfd, const char *pathname, int flag,
* It already exists.
*/
mutex_unlock(&dir->d_inode->i_mutex);
audit_inode(pathname, path.dentry->d_inode);
audit_inode(pathname, path.dentry);
error = -EEXIST;
if (flag & O_EXCL)
@ -2562,7 +2562,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (!error) {
const char *new_name = old_dentry->d_name.name;
fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir,
new_dentry->d_inode, old_dentry->d_inode);
new_dentry->d_inode, old_dentry);
}
fsnotify_oldname_free(old_name);

22
fs/namespace.c
View file

@ -246,7 +246,7 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
list_add(&mnt->mnt_slave, &old->mnt_slave_list);
mnt->mnt_master = old;
CLEAR_MNT_SHARED(mnt);
} else {
} else if (!(flag & CL_PRIVATE)) {
if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old))
list_add(&mnt->mnt_share, &old->mnt_share);
if (IS_MNT_SLAVE(old))
@ -746,6 +746,26 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
return NULL;
}
struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry)
{
struct vfsmount *tree;
down_read(&namespace_sem);
tree = copy_tree(mnt, dentry, CL_COPY_ALL | CL_PRIVATE);
up_read(&namespace_sem);
return tree;
}
void drop_collected_mounts(struct vfsmount *mnt)
{
LIST_HEAD(umount_list);
down_read(&namespace_sem);
spin_lock(&vfsmount_lock);
umount_tree(mnt, 0, &umount_list);
spin_unlock(&vfsmount_lock);
up_read(&namespace_sem);
release_mounts(&umount_list);
}
/*
* @source_mnt : mount tree to be attached
* @nd : place the mount tree @source_mnt is attached

4
fs/open.c
View file

@ -569,7 +569,7 @@ asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
dentry = file->f_path.dentry;
inode = dentry->d_inode;
audit_inode(NULL, inode);
audit_inode(NULL, dentry);
err = -EROFS;
if (IS_RDONLY(inode))
@ -727,7 +727,7 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
goto out;
dentry = file->f_path.dentry;
audit_inode(NULL, dentry->d_inode);
audit_inode(NULL, dentry);
error = chown_common(dentry, user, group);
fput(file);
out:

1
fs/pnode.h
View file

@ -22,6 +22,7 @@
#define CL_COPY_ALL 0x04
#define CL_MAKE_SHARED 0x08
#define CL_PROPAGATION 0x10
#define CL_PRIVATE 0x20
static inline void set_mnt_shared(struct vfsmount *mnt)
{

8
fs/xattr.c
View file

@ -267,7 +267,7 @@ sys_fsetxattr(int fd, char __user *name, void __user *value,
if (!f)
return error;
dentry = f->f_path.dentry;
audit_inode(NULL, dentry->d_inode);
audit_inode(NULL, dentry);
error = setxattr(dentry, name, value, size, flags);
fput(f);
return error;
@ -349,7 +349,7 @@ sys_fgetxattr(int fd, char __user *name, void __user *value, size_t size)
f = fget(fd);
if (!f)
return error;
audit_inode(NULL, f->f_path.dentry->d_inode);
audit_inode(NULL, f->f_path.dentry);
error = getxattr(f->f_path.dentry, name, value, size);
fput(f);
return error;
@ -422,7 +422,7 @@ sys_flistxattr(int fd, char __user *list, size_t size)
f = fget(fd);
if (!f)
return error;
audit_inode(NULL, f->f_path.dentry->d_inode);
audit_inode(NULL, f->f_path.dentry);
error = listxattr(f->f_path.dentry, list, size);
fput(f);
return error;
@ -485,7 +485,7 @@ sys_fremovexattr(int fd, char __user *name)
if (!f)
return error;
dentry = f->f_path.dentry;
audit_inode(NULL, dentry->d_inode);
audit_inode(NULL, dentry);
error = removexattr(dentry, name);
fput(f);
return error;

19
include/linux/audit.h
View file

@ -63,6 +63,8 @@
#define AUDIT_ADD_RULE 1011 /* Add syscall filtering rule */
#define AUDIT_DEL_RULE 1012 /* Delete syscall filtering rule */
#define AUDIT_LIST_RULES 1013 /* List syscall filtering rules */
#define AUDIT_TRIM 1014 /* Trim junk from watched tree */
#define AUDIT_MAKE_EQUIV 1015 /* Append to watched tree */
#define AUDIT_TTY_GET 1016 /* Get TTY auditing status */
#define AUDIT_TTY_SET 1017 /* Set TTY auditing status */
@ -203,6 +205,7 @@
#define AUDIT_SUCCESS 104 /* exit >= 0; value ignored */
#define AUDIT_WATCH 105
#define AUDIT_PERM 106
#define AUDIT_DIR 107
#define AUDIT_ARG0 200
#define AUDIT_ARG1 (AUDIT_ARG0+1)
@ -366,8 +369,8 @@ extern void audit_syscall_entry(int arch,
extern void audit_syscall_exit(int failed, long return_code);
extern void __audit_getname(const char *name);
extern void audit_putname(const char *name);
extern void __audit_inode(const char *name, const struct inode *inode);
extern void __audit_inode_child(const char *dname, const struct inode *inode,
extern void __audit_inode(const char *name, const struct dentry *dentry);
extern void __audit_inode_child(const char *dname, const struct dentry *dentry,
const struct inode *parent);
extern void __audit_ptrace(struct task_struct *t);
@ -381,15 +384,15 @@ static inline void audit_getname(const char *name)
if (unlikely(!audit_dummy_context()))
__audit_getname(name);
}
static inline void audit_inode(const char *name, const struct inode *inode) {
static inline void audit_inode(const char *name, const struct dentry *dentry) {
if (unlikely(!audit_dummy_context()))
__audit_inode(name, inode);
__audit_inode(name, dentry);
}
static inline void audit_inode_child(const char *dname,
const struct inode *inode,
const struct dentry *dentry,
const struct inode *parent) {
if (unlikely(!audit_dummy_context()))
__audit_inode_child(dname, inode, parent);
__audit_inode_child(dname, dentry, parent);
}
void audit_core_dumps(long signr);
@ -477,9 +480,9 @@ extern int audit_signals;
#define audit_dummy_context() 1
#define audit_getname(n) do { ; } while (0)
#define audit_putname(n) do { ; } while (0)
#define __audit_inode(n,i) do { ; } while (0)
#define __audit_inode(n,d) do { ; } while (0)
#define __audit_inode_child(d,i,p) do { ; } while (0)
#define audit_inode(n,i) do { ; } while (0)
#define audit_inode(n,d) do { ; } while (0)
#define audit_inode_child(d,i,p) do { ; } while (0)
#define audit_core_dumps(i) do { ; } while (0)
#define auditsc_get_stamp(c,t,s) do { BUG(); } while (0)

1
include/linux/dcache.h
View file

@ -178,6 +178,7 @@ d_iput: no no no yes
#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched */
extern spinlock_t dcache_lock;
extern seqlock_t rename_lock;
/**
* d_drop - drop a dentry

2
include/linux/fs.h
View file

@ -1470,6 +1470,8 @@ extern long do_mount(char *, char *, char *, unsigned long, void *);
extern struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int);
extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
struct vfsmount *);
extern struct vfsmount *collect_mounts(struct vfsmount *, struct dentry *);
extern void drop_collected_mounts(struct vfsmount *);
extern int vfs_statfs(struct dentry *, struct kstatfs *);

9
include/linux/fsnotify.h
View file

@ -41,8 +41,9 @@ static inline void fsnotify_d_move(struct dentry *entry)
*/
static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
const char *old_name, const char *new_name,
int isdir, struct inode *target, struct inode *source)
int isdir, struct inode *target, struct dentry *moved)
{
struct inode *source = moved->d_inode;
u32 cookie = inotify_get_cookie();
if (old_dir == new_dir)
@ -67,7 +68,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
if (source) {
inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
}
audit_inode_child(new_name, source, new_dir);
audit_inode_child(new_name, moved, new_dir);
}
/*
@ -98,7 +99,7 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
inode_dir_notify(inode, DN_CREATE);
inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name,
dentry->d_inode);
audit_inode_child(dentry->d_name.name, dentry->d_inode, inode);
audit_inode_child(dentry->d_name.name, dentry, inode);
}
/*
@ -109,7 +110,7 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
inode_dir_notify(inode, DN_CREATE);
inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0,
dentry->d_name.name, dentry->d_inode);
audit_inode_child(dentry->d_name.name, dentry->d_inode, inode);
audit_inode_child(dentry->d_name.name, dentry, inode);
}
/*

2
include/linux/inotify.h
View file

@ -120,6 +120,8 @@ extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,
u32);
extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,
struct inode *, __u32);
extern __s32 inotify_clone_watch(struct inotify_watch *, struct inotify_watch *);
extern void inotify_evict_watch(struct inotify_watch *);
extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *);
extern int inotify_rm_wd(struct inotify_handle *, __u32);
extern void inotify_remove_watch_locked(struct inotify_handle *,

4
init/Kconfig
View file

@ -234,6 +234,10 @@ config AUDITSYSCALL
such as SELinux. To use audit's filesystem watch feature, please
ensure that INOTIFY is configured.
config AUDIT_TREE
def_bool y
depends on AUDITSYSCALL && INOTIFY
config IKCONFIG
tristate "Kernel .config support"
---help---

8
ipc/mqueue.c
View file

@ -676,7 +676,7 @@ asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
if (oflag & O_CREAT) {
if (dentry->d_inode) { /* entry already exists */
audit_inode(name, dentry->d_inode);
audit_inode(name, dentry);
error = -EEXIST;
if (oflag & O_EXCL)
goto out;
@ -689,7 +689,7 @@ asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
error = -ENOENT;
if (!dentry->d_inode)
goto out;
audit_inode(name, dentry->d_inode);
audit_inode(name, dentry);
filp = do_open(dentry, oflag);
}
@ -837,7 +837,7 @@ asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
if (unlikely(filp->f_op != &mqueue_file_operations))
goto out_fput;
info = MQUEUE_I(inode);
audit_inode(NULL, inode);
audit_inode(NULL, filp->f_path.dentry);
if (unlikely(!(filp->f_mode & FMODE_WRITE)))
goto out_fput;
@ -921,7 +921,7 @@ asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
if (unlikely(filp->f_op != &mqueue_file_operations))
goto out_fput;
info = MQUEUE_I(inode);
audit_inode(NULL, inode);
audit_inode(NULL, filp->f_path.dentry);
if (unlikely(!(filp->f_mode & FMODE_READ)))
goto out_fput;

1
kernel/Makefile
View file

@ -46,6 +46,7 @@ obj-$(CONFIG_IKCONFIG) += configs.o
obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_SYSFS) += ksysfs.o
obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o

87
kernel/audit.c
View file

@ -468,6 +468,21 @@ int audit_send_list(void *_dest)
return 0;
}
#ifdef CONFIG_AUDIT_TREE
static int prune_tree_thread(void *unused)
{
mutex_lock(&audit_cmd_mutex);
audit_prune_trees();
mutex_unlock(&audit_cmd_mutex);
return 0;
}
void audit_schedule_prune(void)
{
kthread_run(prune_tree_thread, NULL, "audit_prune_tree");
}
#endif
struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
int multi, void *payload, int size)
{
@ -540,6 +555,8 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
case AUDIT_SIGNAL_INFO:
case AUDIT_TTY_GET:
case AUDIT_TTY_SET:
case AUDIT_TRIM:
case AUDIT_MAKE_EQUIV:
if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
err = -EPERM;
break;
@ -756,6 +773,76 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
uid, seq, data, nlmsg_len(nlh),
loginuid, sid);
break;
case AUDIT_TRIM:
audit_trim_trees();
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
if (!ab)
break;
audit_log_format(ab, "auid=%u", loginuid);
if (sid) {
u32 len;
ctx = NULL;
if (selinux_sid_to_string(sid, &ctx, &len))
audit_log_format(ab, " ssid=%u", sid);
else
audit_log_format(ab, " subj=%s", ctx);
kfree(ctx);
}
audit_log_format(ab, " op=trim res=1");
audit_log_end(ab);
break;
case AUDIT_MAKE_EQUIV: {
void *bufp = data;
u32 sizes[2];
size_t len = nlmsg_len(nlh);
char *old, *new;
err = -EINVAL;
if (len < 2 * sizeof(u32))
break;
memcpy(sizes, bufp, 2 * sizeof(u32));
bufp += 2 * sizeof(u32);
len -= 2 * sizeof(u32);
old = audit_unpack_string(&bufp, &len, sizes[0]);
if (IS_ERR(old)) {
err = PTR_ERR(old);
break;
}
new = audit_unpack_string(&bufp, &len, sizes[1]);
if (IS_ERR(new)) {
err = PTR_ERR(new);
kfree(old);
break;
}
/* OK, here comes... */
err = audit_tag_tree(old, new);
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
if (!ab) {
kfree(old);
kfree(new);
break;
}
audit_log_format(ab, "auid=%u", loginuid);
if (sid) {
u32 len;
ctx = NULL;
if (selinux_sid_to_string(sid, &ctx, &len))
audit_log_format(ab, " ssid=%u", sid);
else
audit_log_format(ab, " subj=%s", ctx);
kfree(ctx);
}
audit_log_format(ab, " op=make_equiv old=");
audit_log_untrustedstring(ab, old);
audit_log_format(ab, " new=");
audit_log_untrustedstring(ab, new);
audit_log_format(ab, " res=%d", !err);
audit_log_end(ab);
kfree(old);
kfree(new);
break;
}
case AUDIT_SIGNAL_INFO:
err = selinux_sid_to_string(audit_sig_sid, &ctx, &len);
if (err)

34
kernel/audit.h
View file

@ -73,6 +73,9 @@ struct audit_field {
struct selinux_audit_rule *se_rule;
};
struct audit_tree;
struct audit_chunk;
struct audit_krule {
int vers_ops;
u32 flags;
@ -86,7 +89,8 @@ struct audit_krule {
struct audit_field *arch_f; /* quick access to arch field */
struct audit_field *inode_f; /* quick access to an inode field */
struct audit_watch *watch; /* associated watch */
struct list_head rlist; /* entry in audit_watch.rules list */
struct audit_tree *tree; /* associated watched tree */
struct list_head rlist; /* entry in audit_{watch,tree}.rules list */
};
struct audit_entry {
@ -130,6 +134,34 @@ extern void audit_handle_ievent(struct inotify_watch *, u32, u32, u32,
const char *, struct inode *);
extern int selinux_audit_rule_update(void);
extern struct mutex audit_filter_mutex;
extern void audit_free_rule_rcu(struct rcu_head *);
#ifdef CONFIG_AUDIT_TREE
extern struct audit_chunk *audit_tree_lookup(const struct inode *);
extern void audit_put_chunk(struct audit_chunk *);
extern int audit_tree_match(struct audit_chunk *, struct audit_tree *);
extern int audit_make_tree(struct audit_krule *, char *, u32);
extern int audit_add_tree_rule(struct audit_krule *);
extern int audit_remove_tree_rule(struct audit_krule *);
extern void audit_trim_trees(void);
extern int audit_tag_tree(char *old, char *new);
extern void audit_schedule_prune(void);
extern void audit_prune_trees(void);
extern const char *audit_tree_path(struct audit_tree *);
extern void audit_put_tree(struct audit_tree *);
#else
#define audit_remove_tree_rule(rule) BUG()
#define audit_add_tree_rule(rule) -EINVAL
#define audit_make_tree(rule, str, op) -EINVAL
#define audit_trim_trees() (void)0
#define audit_put_tree(tree) (void)0
#define audit_tag_tree(old, new) -EINVAL
#define audit_tree_path(rule) "" /* never called */
#endif
extern char *audit_unpack_string(void **, size_t *, size_t);
#ifdef CONFIG_AUDITSYSCALL
extern int __audit_signal_info(int sig, struct task_struct *t);
static inline int audit_signal_info(int sig, struct task_struct *t)

903
kernel/audit_tree.c Normal file
View file

@ -0,0 +1,903 @@
#include "audit.h"
#include <linux/inotify.h>
#include <linux/namei.h>
#include <linux/mount.h>
struct audit_tree;
struct audit_chunk;
struct audit_tree {
atomic_t count;
int goner;
struct audit_chunk *root;
struct list_head chunks;
struct list_head rules;
struct list_head list;
struct list_head same_root;
struct rcu_head head;
char pathname[];
};
struct audit_chunk {
struct list_head hash;
struct inotify_watch watch;
struct list_head trees; /* with root here */
int dead;
int count;
struct rcu_head head;
struct node {
struct list_head list;
struct audit_tree *owner;
unsigned index; /* index; upper bit indicates 'will prune' */
} owners[];
};
static LIST_HEAD(tree_list);
static LIST_HEAD(prune_list);
/*
* One struct chunk is attached to each inode of interest.
* We replace struct chunk on tagging/untagging.
* Rules have pointer to struct audit_tree.
* Rules have struct list_head rlist forming a list of rules over
* the same tree.
* References to struct chunk are collected at audit_inode{,_child}()
* time and used in AUDIT_TREE rule matching.
* These references are dropped at the same time we are calling
* audit_free_names(), etc.
*
* Cyclic lists galore:
* tree.chunks anchors chunk.owners[].list hash_lock
* tree.rules anchors rule.rlist audit_filter_mutex
* chunk.trees anchors tree.same_root hash_lock
* chunk.hash is a hash with middle bits of watch.inode as
* a hash function. RCU, hash_lock
*
* tree is refcounted; one reference for "some rules on rules_list refer to
* it", one for each chunk with pointer to it.
*
* chunk is refcounted by embedded inotify_watch.
*
* node.index allows to get from node.list to containing chunk.
* MSB of that sucker is stolen to mark taggings that we might have to
* revert - several operations have very unpleasant cleanup logics and
* that makes a difference. Some.
*/
static struct inotify_handle *rtree_ih;
static struct audit_tree *alloc_tree(const char *s)
{
struct audit_tree *tree;
tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL);
if (tree) {
atomic_set(&tree->count, 1);
tree->goner = 0;
INIT_LIST_HEAD(&tree->chunks);
INIT_LIST_HEAD(&tree->rules);
INIT_LIST_HEAD(&tree->list);
INIT_LIST_HEAD(&tree->same_root);
tree->root = NULL;
strcpy(tree->pathname, s);
}
return tree;
}
static inline void get_tree(struct audit_tree *tree)
{
atomic_inc(&tree->count);
}
static void __put_tree(struct rcu_head *rcu)
{
struct audit_tree *tree = container_of(rcu, struct audit_tree, head);
kfree(tree);
}
static inline void put_tree(struct audit_tree *tree)
{
if (atomic_dec_and_test(&tree->count))
call_rcu(&tree->head, __put_tree);
}
/* to avoid bringing the entire thing in audit.h */
const char *audit_tree_path(struct audit_tree *tree)
{
return tree->pathname;
}
static struct audit_chunk *alloc_chunk(int count)
{
struct audit_chunk *chunk;
size_t size;
int i;
size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
chunk = kzalloc(size, GFP_KERNEL);
if (!chunk)
return NULL;
INIT_LIST_HEAD(&chunk->hash);
INIT_LIST_HEAD(&chunk->trees);
chunk->count = count;
for (i = 0; i < count; i++) {
INIT_LIST_HEAD(&chunk->owners[i].list);
chunk->owners[i].index = i;
}
inotify_init_watch(&chunk->watch);
return chunk;
}
static void __free_chunk(struct rcu_head *rcu)
{
struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head);
int i;
for (i = 0; i < chunk->count; i++) {
if (chunk->owners[i].owner)
put_tree(chunk->owners[i].owner);
}
kfree(chunk);
}
static inline void free_chunk(struct audit_chunk *chunk)
{
call_rcu(&chunk->head, __free_chunk);
}
void audit_put_chunk(struct audit_chunk *chunk)
{
put_inotify_watch(&chunk->watch);
}
enum {HASH_SIZE = 128};
static struct list_head chunk_hash_heads[HASH_SIZE];
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock);
static inline struct list_head *chunk_hash(const struct inode *inode)
{
unsigned long n = (unsigned long)inode / L1_CACHE_BYTES;
return chunk_hash_heads + n % HASH_SIZE;
}
/* hash_lock is held by caller */
static void insert_hash(struct audit_chunk *chunk)
{
struct list_head *list = chunk_hash(chunk->watch.inode);
list_add_rcu(&chunk->hash, list);
}
/* called under rcu_read_lock */
struct audit_chunk *audit_tree_lookup(const struct inode *inode)
{
struct list_head *list = chunk_hash(inode);
struct list_head *pos;
list_for_each_rcu(pos, list) {
struct audit_chunk *p = container_of(pos, struct audit_chunk, hash);
if (p->watch.inode == inode) {
get_inotify_watch(&p->watch);
return p;
}
}
return NULL;
}
int audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree)
{
int n;
for (n = 0; n < chunk->count; n++)
if (chunk->owners[n].owner == tree)
return 1;
return 0;
}
/* tagging and untagging inodes with trees */
static void untag_chunk(struct audit_chunk *chunk, struct node *p)
{
struct audit_chunk *new;
struct audit_tree *owner;
int size = chunk->count - 1;
int i, j;
mutex_lock(&chunk->watch.inode->inotify_mutex);
if (chunk->dead) {
mutex_unlock(&chunk->watch.inode->inotify_mutex);
return;
}
owner = p->owner;
if (!size) {
chunk->dead = 1;
spin_lock(&hash_lock);
list_del_init(&chunk->trees);
if (owner->root == chunk)
owner->root = NULL;
list_del_init(&p->list);
list_del_rcu(&chunk->hash);
spin_unlock(&hash_lock);
inotify_evict_watch(&chunk->watch);
mutex_unlock(&chunk->watch.inode->inotify_mutex);
put_inotify_watch(&chunk->watch);
return;
}
new = alloc_chunk(size);
if (!new)
goto Fallback;
if (inotify_clone_watch(&chunk->watch, &new->watch) < 0) {
free_chunk(new);
goto Fallback;
}
chunk->dead = 1;
spin_lock(&hash_lock);
list_replace_init(&chunk->trees, &new->trees);
if (owner->root == chunk) {
list_del_init(&owner->same_root);
owner->root = NULL;
}
for (i = j = 0; i < size; i++, j++) {
struct audit_tree *s;
if (&chunk->owners[j] == p) {
list_del_init(&p->list);
i--;
continue;
}
s = chunk->owners[j].owner;
new->owners[i].owner = s;
new->owners[i].index = chunk->owners[j].index - j + i;
if (!s) /* result of earlier fallback */
continue;
get_tree(s);
list_replace_init(&chunk->owners[i].list, &new->owners[j].list);
}
list_replace_rcu(&chunk->hash, &new->hash);
list_for_each_entry(owner, &new->trees, same_root)
owner->root = new;
spin_unlock(&hash_lock);
inotify_evict_watch(&chunk->watch);
mutex_unlock(&chunk->watch.inode->inotify_mutex);
put_inotify_watch(&chunk->watch);
return;
Fallback:
// do the best we can
spin_lock(&hash_lock);
if (owner->root == chunk) {
list_del_init(&owner->same_root);
owner->root = NULL;
}
list_del_init(&p->list);
p->owner = NULL;
put_tree(owner);
spin_unlock(&hash_lock);
mutex_unlock(&chunk->watch.inode->inotify_mutex);
}
static int create_chunk(struct inode *inode, struct audit_tree *tree)
{
struct audit_chunk *chunk = alloc_chunk(1);
if (!chunk)
return -ENOMEM;
if (inotify_add_watch(rtree_ih, &chunk->watch, inode, IN_IGNORED | IN_DELETE_SELF) < 0) {
free_chunk(chunk);
return -ENOSPC;
}
mutex_lock(&inode->inotify_mutex);
spin_lock(&hash_lock);
if (tree->goner) {
spin_unlock(&hash_lock);
chunk->dead = 1;
inotify_evict_watch(&chunk->watch);
mutex_unlock(&inode->inotify_mutex);
put_inotify_watch(&chunk->watch);
return 0;
}
chunk->owners[0].index = (1U << 31);
chunk->owners[0].owner = tree;
get_tree(tree);
list_add(&chunk->owners[0].list, &tree->chunks);
if (!tree->root) {
tree->root = chunk;
list_add(&tree->same_root, &chunk->trees);
}
insert_hash(chunk);
spin_unlock(&hash_lock);
mutex_unlock(&inode->inotify_mutex);
return 0;
}
/* the first tagged inode becomes root of tree */
static int tag_chunk(struct inode *inode, struct audit_tree *tree)
{
struct inotify_watch *watch;
struct audit_tree *owner;
struct audit_chunk *chunk, *old;
struct node *p;
int n;
if (inotify_find_watch(rtree_ih, inode, &watch) < 0)
return create_chunk(inode, tree);
old = container_of(watch, struct audit_chunk, watch);
/* are we already there? */
spin_lock(&hash_lock);
for (n = 0; n < old->count; n++) {
if (old->owners[n].owner == tree) {
spin_unlock(&hash_lock);
put_inotify_watch(watch);
return 0;
}
}
spin_unlock(&hash_lock);
chunk = alloc_chunk(old->count + 1);
if (!chunk)
return -ENOMEM;
mutex_lock(&inode->inotify_mutex);
if (inotify_clone_watch(&old->watch, &chunk->watch) < 0) {
mutex_unlock(&inode->inotify_mutex);
free_chunk(chunk);
return -ENOSPC;
}
spin_lock(&hash_lock);
if (tree->goner) {
spin_unlock(&hash_lock);
chunk->dead = 1;
inotify_evict_watch(&chunk->watch);
mutex_unlock(&inode->inotify_mutex);
put_inotify_watch(&chunk->watch);
return 0;
}
list_replace_init(&old->trees, &chunk->trees);
for (n = 0, p = chunk->owners; n < old->count; n++, p++) {
struct audit_tree *s = old->owners[n].owner;
p->owner = s;
p->index = old->owners[n].index;
if (!s) /* result of fallback in untag */
continue;
get_tree(s);
list_replace_init(&old->owners[n].list, &p->list);
}
p->index = (chunk->count - 1) | (1U<<31);
p->owner = tree;
get_tree(tree);
list_add(&p->list, &tree->chunks);
list_replace_rcu(&old->hash, &chunk->hash);
list_for_each_entry(owner, &chunk->trees, same_root)
owner->root = chunk;
old->dead = 1;
if (!tree->root) {
tree->root = chunk;
list_add(&tree->same_root, &chunk->trees);
}
spin_unlock(&hash_lock);
inotify_evict_watch(&old->watch);
mutex_unlock(&inode->inotify_mutex);
put_inotify_watch(&old->watch);
return 0;
}
static struct audit_chunk *find_chunk(struct node *p)
{
int index = p->index & ~(1U<<31);
p -= index;
return container_of(p, struct audit_chunk, owners[0]);
}
static void kill_rules(struct audit_tree *tree)
{
struct audit_krule *rule, *next;
struct audit_entry *entry;
struct audit_buffer *ab;
list_for_each_entry_safe(rule, next, &tree->rules, rlist) {
entry = container_of(rule, struct audit_entry, rule);
list_del_init(&rule->rlist);
if (rule->tree) {
/* not a half-baked one */
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, "op=remove rule dir=");
audit_log_untrustedstring(ab, rule->tree->pathname);
if (rule->filterkey) {
audit_log_format(ab, " key=");
audit_log_untrustedstring(ab, rule->filterkey);
} else
audit_log_format(ab, " key=(null)");
audit_log_format(ab, " list=%d res=1", rule->listnr);
audit_log_end(ab);
rule->tree = NULL;
list_del_rcu(&entry->list);
call_rcu(&entry->rcu, audit_free_rule_rcu);
}
}
}
/*
* finish killing struct audit_tree
*/
static void prune_one(struct audit_tree *victim)
{
spin_lock(&hash_lock);
while (!list_empty(&victim->chunks)) {
struct node *p;
struct audit_chunk *chunk;
p = list_entry(victim->chunks.next, struct node, list);
chunk = find_chunk(p);
get_inotify_watch(&chunk->watch);
spin_unlock(&hash_lock);
untag_chunk(chunk, p);
put_inotify_watch(&chunk->watch);
spin_lock(&hash_lock);
}
spin_unlock(&hash_lock);
put_tree(victim);
}
/* trim the uncommitted chunks from tree */
static void trim_marked(struct audit_tree *tree)
{
struct list_head *p, *q;
spin_lock(&hash_lock);
if (tree->goner) {
spin_unlock(&hash_lock);
return;
}
/* reorder */
for (p = tree->chunks.next; p != &tree->chunks; p = q) {
struct node *node = list_entry(p, struct node, list);
q = p->next;
if (node->index & (1U<<31)) {
list_del_init(p);
list_add(p, &tree->chunks);
}
}
while (!list_empty(&tree->chunks)) {
struct node *node;
struct audit_chunk *chunk;
node = list_entry(tree->chunks.next, struct node, list);
/* have we run out of marked? */
if (!(node->index & (1U<<31)))
break;
chunk = find_chunk(node);
get_inotify_watch(&chunk->watch);
spin_unlock(&hash_lock);
untag_chunk(chunk, node);
put_inotify_watch(&chunk->watch);
spin_lock(&hash_lock);
}
if (!tree->root && !tree->goner) {
tree->goner = 1;
spin_unlock(&hash_lock);
mutex_lock(&audit_filter_mutex);
kill_rules(tree);
list_del_init(&tree->list);
mutex_unlock(&audit_filter_mutex);
prune_one(tree);
} else {
spin_unlock(&hash_lock);
}
}
/* called with audit_filter_mutex */
int audit_remove_tree_rule(struct audit_krule *rule)
{
struct audit_tree *tree;
tree = rule->tree;
if (tree) {
spin_lock(&hash_lock);
list_del_init(&rule->rlist);
if (list_empty(&tree->rules) && !tree->goner) {
tree->root = NULL;
list_del_init(&tree->same_root);
tree->goner = 1;
list_move(&tree->list, &prune_list);
rule->tree = NULL;
spin_unlock(&hash_lock);
audit_schedule_prune();
return 1;
}
rule->tree = NULL;
spin_unlock(&hash_lock);
return 1;
}
return 0;
}
void audit_trim_trees(void)
{
struct list_head cursor;
mutex_lock(&audit_filter_mutex);
list_add(&cursor, &tree_list);
while (cursor.next != &tree_list) {
struct audit_tree *tree;
struct nameidata nd;
struct vfsmount *root_mnt;
struct node *node;
struct list_head list;
int err;
tree = container_of(cursor.next, struct audit_tree, list);
get_tree(tree);
list_del(&cursor);
list_add(&cursor, &tree->list);
mutex_unlock(&audit_filter_mutex);
err = path_lookup(tree->pathname, 0, &nd);
if (err)
goto skip_it;
root_mnt = collect_mounts(nd.mnt, nd.dentry);
path_release(&nd);
if (!root_mnt)
goto skip_it;
list_add_tail(&list, &root_mnt->mnt_list);
spin_lock(&hash_lock);
list_for_each_entry(node, &tree->chunks, list) {
struct audit_chunk *chunk = find_chunk(node);
struct inode *inode = chunk->watch.inode;
struct vfsmount *mnt;
node->index |= 1U<<31;
list_for_each_entry(mnt, &list, mnt_list) {
if (mnt->mnt_root->d_inode == inode) {
node->index &= ~(1U<<31);
break;
}
}
}
spin_unlock(&hash_lock);
trim_marked(tree);
put_tree(tree);
list_del_init(&list);
drop_collected_mounts(root_mnt);
skip_it:
mutex_lock(&audit_filter_mutex);
}
list_del(&cursor);
mutex_unlock(&audit_filter_mutex);
}
static int is_under(struct vfsmount *mnt, struct dentry *dentry,
struct nameidata *nd)
{
if (mnt != nd->mnt) {
for (;;) {
if (mnt->mnt_parent == mnt)
return 0;
if (mnt->mnt_parent == nd->mnt)
break;
mnt = mnt->mnt_parent;
}
dentry = mnt->mnt_mountpoint;
}
return is_subdir(dentry, nd->dentry);
}
int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
{
if (pathname[0] != '/' ||
rule->listnr != AUDIT_FILTER_EXIT ||
op & ~AUDIT_EQUAL ||
rule->inode_f || rule->watch || rule->tree)
return -EINVAL;
rule->tree = alloc_tree(pathname);
if (!rule->tree)
return -ENOMEM;
return 0;
}
void audit_put_tree(struct audit_tree *tree)
{
put_tree(tree);
}
/* called with audit_filter_mutex */
int audit_add_tree_rule(struct audit_krule *rule)
{
struct audit_tree *seed = rule->tree, *tree;
struct nameidata nd;
struct vfsmount *mnt, *p;
struct list_head list;
int err;
list_for_each_entry(tree, &tree_list, list) {
if (!strcmp(seed->pathname, tree->pathname)) {
put_tree(seed);
rule->tree = tree;
list_add(&rule->rlist, &tree->rules);
return 0;
}
}
tree = seed;
list_add(&tree->list, &tree_list);
list_add(&rule->rlist, &tree->rules);
/* do not set rule->tree yet */
mutex_unlock(&audit_filter_mutex);
err = path_lookup(tree->pathname, 0, &nd);
if (err)
goto Err;
mnt = collect_mounts(nd.mnt, nd.dentry);
path_release(&nd);
if (!mnt) {
err = -ENOMEM;
goto Err;
}
list_add_tail(&list, &mnt->mnt_list);
get_tree(tree);
list_for_each_entry(p, &list, mnt_list) {
err = tag_chunk(p->mnt_root->d_inode, tree);
if (err)
break;
}
list_del(&list);
drop_collected_mounts(mnt);
if (!err) {
struct node *node;
spin_lock(&hash_lock);
list_for_each_entry(node, &tree->chunks, list)
node->index &= ~(1U<<31);
spin_unlock(&hash_lock);
} else {
trim_marked(tree);
goto Err;
}
mutex_lock(&audit_filter_mutex);
if (list_empty(&rule->rlist)) {
put_tree(tree);
return -ENOENT;
}
rule->tree = tree;
put_tree(tree);
return 0;
Err:
mutex_lock(&audit_filter_mutex);
list_del_init(&tree->list);
list_del_init(&tree->rules);
put_tree(tree);
return err;
}
int audit_tag_tree(char *old, char *new)
{
struct list_head cursor, barrier;
int failed = 0;
struct nameidata nd;
struct vfsmount *tagged;
struct list_head list;
struct vfsmount *mnt;
struct dentry *dentry;
int err;
err = path_lookup(new, 0, &nd);
if (err)
return err;
tagged = collect_mounts(nd.mnt, nd.dentry);
path_release(&nd);
if (!tagged)
return -ENOMEM;
err = path_lookup(old, 0, &nd);
if (err) {
drop_collected_mounts(tagged);
return err;
}
mnt = mntget(nd.mnt);
dentry = dget(nd.dentry);
path_release(&nd);
if (dentry == tagged->mnt_root && dentry == mnt->mnt_root)
follow_up(&mnt, &dentry);
list_add_tail(&list, &tagged->mnt_list);
mutex_lock(&audit_filter_mutex);
list_add(&barrier, &tree_list);
list_add(&cursor, &barrier);
while (cursor.next != &tree_list) {
struct audit_tree *tree;
struct vfsmount *p;
tree = container_of(cursor.next, struct audit_tree, list);
get_tree(tree);
list_del(&cursor);
list_add(&cursor, &tree->list);
mutex_unlock(&audit_filter_mutex);
err = path_lookup(tree->pathname, 0, &nd);
if (err) {
put_tree(tree);
mutex_lock(&audit_filter_mutex);
continue;
}
spin_lock(&vfsmount_lock);
if (!is_under(mnt, dentry, &nd)) {
spin_unlock(&vfsmount_lock);
path_release(&nd);
put_tree(tree);
mutex_lock(&audit_filter_mutex);
continue;
}
spin_unlock(&vfsmount_lock);
path_release(&nd);
list_for_each_entry(p, &list, mnt_list) {
failed = tag_chunk(p->mnt_root->d_inode, tree);
if (failed)
break;
}
if (failed) {
put_tree(tree);
mutex_lock(&audit_filter_mutex);
break;
}
mutex_lock(&audit_filter_mutex);
spin_lock(&hash_lock);
if (!tree->goner) {
list_del(&tree->list);
list_add(&tree->list, &tree_list);
}
spin_unlock(&hash_lock);
put_tree(tree);
}
while (barrier.prev != &tree_list) {
struct audit_tree *tree;
tree = container_of(barrier.prev, struct audit_tree, list);
get_tree(tree);
list_del(&tree->list);
list_add(&tree->list, &barrier);
mutex_unlock(&audit_filter_mutex);
if (!failed) {
struct node *node;
spin_lock(&hash_lock);
list_for_each_entry(node, &tree->chunks, list)
node->index &= ~(1U<<31);
spin_unlock(&hash_lock);
} else {
trim_marked(tree);
}
put_tree(tree);
mutex_lock(&audit_filter_mutex);
}
list_del(&barrier);
list_del(&cursor);
list_del(&list);
mutex_unlock(&audit_filter_mutex);
dput(dentry);
mntput(mnt);
drop_collected_mounts(tagged);
return failed;
}
/*
* That gets run when evict_chunk() ends up needing to kill audit_tree.
* Runs from a separate thread, with audit_cmd_mutex held.
*/
void audit_prune_trees(void)
{
mutex_lock(&audit_filter_mutex);
while (!list_empty(&prune_list)) {
struct audit_tree *victim;
victim = list_entry(prune_list.next, struct audit_tree, list);
list_del_init(&victim->list);
mutex_unlock(&audit_filter_mutex);
prune_one(victim);
mutex_lock(&audit_filter_mutex);
}
mutex_unlock(&audit_filter_mutex);
}
/*
* Here comes the stuff asynchronous to auditctl operations
*/
/* inode->inotify_mutex is locked */
static void evict_chunk(struct audit_chunk *chunk)
{
struct audit_tree *owner;
int n;
if (chunk->dead)
return;
chunk->dead = 1;
mutex_lock(&audit_filter_mutex);
spin_lock(&hash_lock);
while (!list_empty(&chunk->trees)) {
owner = list_entry(chunk->trees.next,
struct audit_tree, same_root);
owner->goner = 1;
owner->root = NULL;
list_del_init(&owner->same_root);
spin_unlock(&hash_lock);
kill_rules(owner);
list_move(&owner->list, &prune_list);
audit_schedule_prune();
spin_lock(&hash_lock);
}
list_del_rcu(&chunk->hash);
for (n = 0; n < chunk->count; n++)
list_del_init(&chunk->owners[n].list);
spin_unlock(&hash_lock);
mutex_unlock(&audit_filter_mutex);
}
static void handle_event(struct inotify_watch *watch, u32 wd, u32 mask,
u32 cookie, const char *dname, struct inode *inode)
{
struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch);
if (mask & IN_IGNORED) {
evict_chunk(chunk);
put_inotify_watch(watch);
}
}
static void destroy_watch(struct inotify_watch *watch)
{
struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch);
free_chunk(chunk);
}
static const struct inotify_operations rtree_inotify_ops = {
.handle_event = handle_event,
.destroy_watch = destroy_watch,
};
static int __init audit_tree_init(void)
{
int i;
rtree_ih = inotify_init(&rtree_inotify_ops);
if (IS_ERR(rtree_ih))
audit_panic("cannot initialize inotify handle for rectree watches");
for (i = 0; i < HASH_SIZE; i++)
INIT_LIST_HEAD(&chunk_hash_heads[i]);
return 0;
}
__initcall(audit_tree_init);

64
kernel/auditfilter.c
View file

@ -87,7 +87,7 @@ struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
#endif
};
static DEFINE_MUTEX(audit_filter_mutex);
DEFINE_MUTEX(audit_filter_mutex);
/* Inotify handle */
extern struct inotify_handle *audit_ih;
@ -145,7 +145,7 @@ static inline void audit_free_rule(struct audit_entry *e)
kfree(e);
}
static inline void audit_free_rule_rcu(struct rcu_head *head)
void audit_free_rule_rcu(struct rcu_head *head)
{
struct audit_entry *e = container_of(head, struct audit_entry, rcu);
audit_free_rule(e);
@ -217,7 +217,7 @@ static inline struct audit_entry *audit_init_entry(u32 field_count)
/* Unpack a filter field's string representation from user-space
* buffer. */
static char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
{
char *str;
@ -247,7 +247,7 @@ static inline int audit_to_inode(struct audit_krule *krule,
struct audit_field *f)
{
if (krule->listnr != AUDIT_FILTER_EXIT ||
krule->watch || krule->inode_f)
krule->watch || krule->inode_f || krule->tree)
return -EINVAL;
krule->inode_f = f;
@ -266,7 +266,7 @@ static int audit_to_watch(struct audit_krule *krule, char *path, int len,
if (path[0] != '/' || path[len-1] == '/' ||
krule->listnr != AUDIT_FILTER_EXIT ||
op & ~AUDIT_EQUAL ||
krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */
krule->inode_f || krule->watch || krule->tree)
return -EINVAL;
watch = audit_init_watch(path);
@ -622,6 +622,17 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
goto exit_free;
}
break;
case AUDIT_DIR:
str = audit_unpack_string(&bufp, &remain, f->val);
if (IS_ERR(str))
goto exit_free;
entry->rule.buflen += f->val;
err = audit_make_tree(&entry->rule, str, f->op);
kfree(str);
if (err)
goto exit_free;
break;
case AUDIT_INODE:
err = audit_to_inode(&entry->rule, f);
if (err)
@ -668,7 +679,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
}
/* Pack a filter field's string representation into data block. */
static inline size_t audit_pack_string(void **bufp, char *str)
static inline size_t audit_pack_string(void **bufp, const char *str)
{
size_t len = strlen(str);
@ -747,6 +758,11 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
data->buflen += data->values[i] =
audit_pack_string(&bufp, krule->watch->path);
break;
case AUDIT_DIR:
data->buflen += data->values[i] =
audit_pack_string(&bufp,
audit_tree_path(krule->tree));
break;
case AUDIT_FILTERKEY:
data->buflen += data->values[i] =
audit_pack_string(&bufp, krule->filterkey);
@ -795,6 +811,11 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
if (strcmp(a->watch->path, b->watch->path))
return 1;
break;
case AUDIT_DIR:
if (strcmp(audit_tree_path(a->tree),
audit_tree_path(b->tree)))
return 1;
break;
case AUDIT_FILTERKEY:
/* both filterkeys exist based on above type compare */
if (strcmp(a->filterkey, b->filterkey))
@ -897,6 +918,14 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
new->inode_f = old->inode_f;
new->watch = NULL;
new->field_count = old->field_count;
/*
* note that we are OK with not refcounting here; audit_match_tree()
* never dereferences tree and we can't get false positives there
* since we'd have to have rule gone from the list *and* removed
* before the chunks found by lookup had been allocated, i.e. before
* the beginning of list scan.
*/
new->tree = old->tree;
memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
/* deep copy this information, updating the se_rule fields, because
@ -1217,6 +1246,7 @@ static inline int audit_add_rule(struct audit_entry *entry,
struct audit_entry *e;
struct audit_field *inode_f = entry->rule.inode_f;
struct audit_watch *watch = entry->rule.watch;
struct audit_tree *tree = entry->rule.tree;
struct nameidata *ndp = NULL, *ndw = NULL;
int h, err;
#ifdef CONFIG_AUDITSYSCALL
@ -1238,6 +1268,9 @@ static inline int audit_add_rule(struct audit_entry *entry,
mutex_unlock(&audit_filter_mutex);
if (e) {
err = -EEXIST;
/* normally audit_add_tree_rule() will free it on failure */
if (tree)
audit_put_tree(tree);
goto error;
}
@ -1259,6 +1292,13 @@ static inline int audit_add_rule(struct audit_entry *entry,
h = audit_hash_ino((u32)watch->ino);
list = &audit_inode_hash[h];
}
if (tree) {
err = audit_add_tree_rule(&entry->rule);
if (err) {
mutex_unlock(&audit_filter_mutex);
goto error;
}
}
if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
list_add_rcu(&entry->list, list);
@ -1292,6 +1332,7 @@ static inline int audit_del_rule(struct audit_entry *entry,
struct audit_entry *e;
struct audit_field *inode_f = entry->rule.inode_f;
struct audit_watch *watch, *tmp_watch = entry->rule.watch;
struct audit_tree *tree = entry->rule.tree;
LIST_HEAD(inotify_list);
int h, ret = 0;
#ifdef CONFIG_AUDITSYSCALL
@ -1336,6 +1377,9 @@ static inline int audit_del_rule(struct audit_entry *entry,
}
}
if (e->rule.tree)
audit_remove_tree_rule(&e->rule);
list_del_rcu(&e->list);
call_rcu(&e->rcu, audit_free_rule_rcu);
@ -1354,6 +1398,8 @@ static inline int audit_del_rule(struct audit_entry *entry,
out:
if (tmp_watch)
audit_put_watch(tmp_watch); /* match initial get */
if (tree)
audit_put_tree(tree); /* that's the temporary one */
return ret;
}
@ -1737,6 +1783,7 @@ int selinux_audit_rule_update(void)
{
struct audit_entry *entry, *n, *nentry;
struct audit_watch *watch;
struct audit_tree *tree;
int i, err = 0;
/* audit_filter_mutex synchronizes the writers */
@ -1748,6 +1795,7 @@ int selinux_audit_rule_update(void)
continue;
watch = entry->rule.watch;
tree = entry->rule.tree;
nentry = audit_dupe_rule(&entry->rule, watch);
if (unlikely(IS_ERR(nentry))) {
/* save the first error encountered for the
@ -1763,7 +1811,9 @@ int selinux_audit_rule_update(void)
list_add(&nentry->rule.rlist,
&watch->rules);
list_del(&entry->rule.rlist);
}
} else if (tree)
list_replace_init(&entry->rule.rlist,
&nentry->rule.rlist);
list_replace_rcu(&entry->list, &nentry->list);
}
call_rcu(&entry->rcu, audit_free_rule_rcu);

225
kernel/auditsc.c
View file

@ -65,6 +65,7 @@
#include <linux/binfmts.h>
#include <linux/highmem.h>
#include <linux/syscalls.h>
#include <linux/inotify.h>
#include "audit.h"
@ -179,6 +180,11 @@ struct audit_aux_data_pids {
int pid_count;
};
struct audit_tree_refs {
struct audit_tree_refs *next;
struct audit_chunk *c[31];
};
/* The per-task audit context. */
struct audit_context {
int dummy; /* must be the first element */
@ -211,6 +217,9 @@ struct audit_context {
pid_t target_pid;
u32 target_sid;
struct audit_tree_refs *trees, *first_trees;
int tree_count;
#if AUDIT_DEBUG
int put_count;
int ino_count;
@ -265,6 +274,117 @@ static int audit_match_perm(struct audit_context *ctx, int mask)
}
}
/*
* We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
* ->first_trees points to its beginning, ->trees - to the current end of data.
* ->tree_count is the number of free entries in array pointed to by ->trees.
* Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
* "empty" becomes (p, p, 31) afterwards. We don't shrink the list (and seriously,
* it's going to remain 1-element for almost any setup) until we free context itself.
* References in it _are_ dropped - at the same time we free/drop aux stuff.
*/
#ifdef CONFIG_AUDIT_TREE
static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
{
struct audit_tree_refs *p = ctx->trees;
int left = ctx->tree_count;
if (likely(left)) {
p->c[--left] = chunk;
ctx->tree_count = left;
return 1;
}
if (!p)
return 0;
p = p->next;
if (p) {
p->c[30] = chunk;
ctx->trees = p;
ctx->tree_count = 30;
return 1;
}
return 0;
}
static int grow_tree_refs(struct audit_context *ctx)
{
struct audit_tree_refs *p = ctx->trees;
ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
if (!ctx->trees) {
ctx->trees = p;
return 0;
}
if (p)
p->next = ctx->trees;
else
ctx->first_trees = ctx->trees;
ctx->tree_count = 31;
return 1;
}
#endif
static void unroll_tree_refs(struct audit_context *ctx,
struct audit_tree_refs *p, int count)
{
#ifdef CONFIG_AUDIT_TREE
struct audit_tree_refs *q;
int n;
if (!p) {
/* we started with empty chain */
p = ctx->first_trees;
count = 31;
/* if the very first allocation has failed, nothing to do */
if (!p)
return;
}
n = count;
for (q = p; q != ctx->trees; q = q->next, n = 31) {
while (n--) {
audit_put_chunk(q->c[n]);
q->c[n] = NULL;
}
}
while (n-- > ctx->tree_count) {
audit_put_chunk(q->c[n]);
q->c[n] = NULL;
}
ctx->trees = p;
ctx->tree_count = count;
#endif
}
static void free_tree_refs(struct audit_context *ctx)
{
struct audit_tree_refs *p, *q;
for (p = ctx->first_trees; p; p = q) {
q = p->next;
kfree(p);
}
}
static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
{
#ifdef CONFIG_AUDIT_TREE
struct audit_tree_refs *p;
int n;
if (!tree)
return 0;
/* full ones */
for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
for (n = 0; n < 31; n++)
if (audit_tree_match(p->c[n], tree))
return 1;
}
/* partial */
if (p) {
for (n = ctx->tree_count; n < 31; n++)
if (audit_tree_match(p->c[n], tree))
return 1;
}
#endif
return 0;
}
/* Determine if any context name data matches a rule's watch data */
/* Compare a task_struct with an audit_rule. Return 1 on match, 0
* otherwise. */
@ -379,6 +499,10 @@ static int audit_filter_rules(struct task_struct *tsk,
result = (name->dev == rule->watch->dev &&
name->ino == rule->watch->ino);
break;
case AUDIT_DIR:
if (ctx)
result = match_tree_refs(ctx, rule->tree);
break;
case AUDIT_LOGINUID:
result = 0;
if (ctx)
@ -727,6 +851,8 @@ static inline void audit_free_context(struct audit_context *context)
context->name_count, count);
}
audit_free_names(context);
unroll_tree_refs(context, NULL, 0);
free_tree_refs(context);
audit_free_aux(context);
kfree(context->filterkey);
kfree(context);
@ -1270,6 +1396,7 @@ void audit_syscall_exit(int valid, long return_code)
tsk->audit_context = new_context;
} else {
audit_free_names(context);
unroll_tree_refs(context, NULL, 0);
audit_free_aux(context);
context->aux = NULL;
context->aux_pids = NULL;
@ -1281,6 +1408,95 @@ void audit_syscall_exit(int valid, long return_code)
}
}
static inline void handle_one(const struct inode *inode)
{
#ifdef CONFIG_AUDIT_TREE
struct audit_context *context;
struct audit_tree_refs *p;
struct audit_chunk *chunk;
int count;
if (likely(list_empty(&inode->inotify_watches)))
return;
context = current->audit_context;
p = context->trees;
count = context->tree_count;
rcu_read_lock();
chunk = audit_tree_lookup(inode);
rcu_read_unlock();
if (!chunk)
return;
if (likely(put_tree_ref(context, chunk)))
return;
if (unlikely(!grow_tree_refs(context))) {
printk(KERN_WARNING "out of memory, audit has lost a tree reference");
audit_set_auditable(context);
audit_put_chunk(chunk);
unroll_tree_refs(context, p, count);
return;
}
put_tree_ref(context, chunk);
#endif
}
static void handle_path(const struct dentry *dentry)
{
#ifdef CONFIG_AUDIT_TREE
struct audit_context *context;
struct audit_tree_refs *p;
const struct dentry *d, *parent;
struct audit_chunk *drop;
unsigned long seq;
int count;
context = current->audit_context;
p = context->trees;
count = context->tree_count;
retry:
drop = NULL;
d = dentry;
rcu_read_lock();
seq = read_seqbegin(&rename_lock);
for(;;) {
struct inode *inode = d->d_inode;
if (inode && unlikely(!list_empty(&inode->inotify_watches))) {
struct audit_chunk *chunk;
chunk = audit_tree_lookup(inode);
if (chunk) {
if (unlikely(!put_tree_ref(context, chunk))) {
drop = chunk;
break;
}
}
}
parent = d->d_parent;
if (parent == d)
break;
d = parent;
}
if (unlikely(read_seqretry(&rename_lock, seq) || drop)) { /* in this order */
rcu_read_unlock();
if (!drop) {
/* just a race with rename */
unroll_tree_refs(context, p, count);
goto retry;
}
audit_put_chunk(drop);
if (grow_tree_refs(context)) {
/* OK, got more space */
unroll_tree_refs(context, p, count);
goto retry;
}
/* too bad */
printk(KERN_WARNING
"out of memory, audit has lost a tree reference");
unroll_tree_refs(context, p, count);
audit_set_auditable(context);
return;
}
rcu_read_unlock();
#endif
}
/**
* audit_getname - add a name to the list
* @name: name to add
@ -1403,10 +1619,11 @@ static void audit_copy_inode(struct audit_names *name, const struct inode *inode
*
* Called from fs/namei.c:path_lookup().
*/
void __audit_inode(const char *name, const struct inode *inode)
void __audit_inode(const char *name, const struct dentry *dentry)
{
int idx;
struct audit_context *context = current->audit_context;
const struct inode *inode = dentry->d_inode;
if (!context->in_syscall)
return;
@ -1426,6 +1643,7 @@ void __audit_inode(const char *name, const struct inode *inode)
idx = context->name_count - 1;
context->names[idx].name = NULL;
}
handle_path(dentry);
audit_copy_inode(&context->names[idx], inode);
}
@ -1443,17 +1661,20 @@ void __audit_inode(const char *name, const struct inode *inode)
* must be hooked prior, in order to capture the target inode during
* unsuccessful attempts.
*/
void __audit_inode_child(const char *dname, const struct inode *inode,
void __audit_inode_child(const char *dname, const struct dentry *dentry,
const struct inode *parent)
{
int idx;
struct audit_context *context = current->audit_context;
const char *found_parent = NULL, *found_child = NULL;
const struct inode *inode = dentry->d_inode;
int dirlen = 0;
if (!context->in_syscall)
return;
if (inode)
handle_one(inode);
/* determine matching parent */
if (!dname)
goto add_names;