linux/kernel/audit.h
Paul Moore 55422d0bd2 audit: replace getname()/putname() hacks with reference counters
In order to ensure that filenames are not released before the audit
subsystem is done with the strings there are a number of hacks built
into the fs and audit subsystems around getname() and putname().  To
say these hacks are "ugly" would be kind.

This patch removes the filename hackery in favor of a more
conventional reference count based approach.  The diffstat below tells
most of the story; lots of audit/fs specific code is replaced with a
traditional reference count based approach that is easily understood,
even by those not familiar with the audit and/or fs subsystems.

CC: viro@zeniv.linux.org.uk
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-23 00:23:58 -05:00

326 lines
9.9 KiB
C

/* audit -- definition of audit_context structure and supporting types
*
* Copyright 2003-2004 Red Hat, Inc.
* Copyright 2005 Hewlett-Packard Development Company, L.P.
* Copyright 2005 IBM Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/audit.h>
#include <linux/skbuff.h>
#include <uapi/linux/mqueue.h>
/* AUDIT_NAMES is the number of slots we reserve in the audit_context
* for saving names from getname(). If we get more names we will allocate
* a name dynamically and also add those to the list anchored by names_list. */
#define AUDIT_NAMES 5
/* At task start time, the audit_state is set in the audit_context using
a per-task filter. At syscall entry, the audit_state is augmented by
the syscall filter. */
enum audit_state {
AUDIT_DISABLED, /* Do not create per-task audit_context.
* No syscall-specific audit records can
* be generated. */
AUDIT_BUILD_CONTEXT, /* Create the per-task audit_context,
* and fill it in at syscall
* entry time. This makes a full
* syscall record available if some
* other part of the kernel decides it
* should be recorded. */
AUDIT_RECORD_CONTEXT /* Create the per-task audit_context,
* always fill it in at syscall entry
* time, and always write out the audit
* record at syscall exit time. */
};
/* Rule lists */
struct audit_watch;
struct audit_tree;
struct audit_chunk;
struct audit_entry {
struct list_head list;
struct rcu_head rcu;
struct audit_krule rule;
};
struct audit_cap_data {
kernel_cap_t permitted;
kernel_cap_t inheritable;
union {
unsigned int fE; /* effective bit of file cap */
kernel_cap_t effective; /* effective set of process */
};
};
/* When fs/namei.c:getname() is called, we store the pointer in name and bump
* the refcnt in the associated filename struct.
*
* Further, in fs/namei.c:path_lookup() we store the inode and device.
*/
struct audit_names {
struct list_head list; /* audit_context->names_list */
struct filename *name;
int name_len; /* number of chars to log */
bool hidden; /* don't log this record */
unsigned long ino;
dev_t dev;
umode_t mode;
kuid_t uid;
kgid_t gid;
dev_t rdev;
u32 osid;
struct audit_cap_data fcap;
unsigned int fcap_ver;
unsigned char type; /* record type */
/*
* This was an allocated audit_names and not from the array of
* names allocated in the task audit context. Thus this name
* should be freed on syscall exit.
*/
bool should_free;
};
struct audit_proctitle {
int len; /* length of the cmdline field. */
char *value; /* the cmdline field */
};
/* The per-task audit context. */
struct audit_context {
int dummy; /* must be the first element */
int in_syscall; /* 1 if task is in a syscall */
enum audit_state state, current_state;
unsigned int serial; /* serial number for record */
int major; /* syscall number */
struct timespec ctime; /* time of syscall entry */
unsigned long argv[4]; /* syscall arguments */
long return_code;/* syscall return code */
u64 prio;
int return_valid; /* return code is valid */
/*
* The names_list is the list of all audit_names collected during this
* syscall. The first AUDIT_NAMES entries in the names_list will
* actually be from the preallocated_names array for performance
* reasons. Except during allocation they should never be referenced
* through the preallocated_names array and should only be found/used
* by running the names_list.
*/
struct audit_names preallocated_names[AUDIT_NAMES];
int name_count; /* total records in names_list */
struct list_head names_list; /* struct audit_names->list anchor */
char *filterkey; /* key for rule that triggered record */
struct path pwd;
struct audit_aux_data *aux;
struct audit_aux_data *aux_pids;
struct sockaddr_storage *sockaddr;
size_t sockaddr_len;
/* Save things to print about task_struct */
pid_t pid, ppid;
kuid_t uid, euid, suid, fsuid;
kgid_t gid, egid, sgid, fsgid;
unsigned long personality;
int arch;
pid_t target_pid;
kuid_t target_auid;
kuid_t target_uid;
unsigned int target_sessionid;
u32 target_sid;
char target_comm[TASK_COMM_LEN];
struct audit_tree_refs *trees, *first_trees;
struct list_head killed_trees;
int tree_count;
int type;
union {
struct {
int nargs;
long args[6];
} socketcall;
struct {
kuid_t uid;
kgid_t gid;
umode_t mode;
u32 osid;
int has_perm;
uid_t perm_uid;
gid_t perm_gid;
umode_t perm_mode;
unsigned long qbytes;
} ipc;
struct {
mqd_t mqdes;
struct mq_attr mqstat;
} mq_getsetattr;
struct {
mqd_t mqdes;
int sigev_signo;
} mq_notify;
struct {
mqd_t mqdes;
size_t msg_len;
unsigned int msg_prio;
struct timespec abs_timeout;
} mq_sendrecv;
struct {
int oflag;
umode_t mode;
struct mq_attr attr;
} mq_open;
struct {
pid_t pid;
struct audit_cap_data cap;
} capset;
struct {
int fd;
int flags;
} mmap;
struct {
int argc;
} execve;
};
int fds[2];
struct audit_proctitle proctitle;
};
extern u32 audit_ever_enabled;
extern void audit_copy_inode(struct audit_names *name,
const struct dentry *dentry,
const struct inode *inode);
extern void audit_log_cap(struct audit_buffer *ab, char *prefix,
kernel_cap_t *cap);
extern void audit_log_name(struct audit_context *context,
struct audit_names *n, struct path *path,
int record_num, int *call_panic);
extern int audit_pid;
#define AUDIT_INODE_BUCKETS 32
extern struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
static inline int audit_hash_ino(u32 ino)
{
return (ino & (AUDIT_INODE_BUCKETS-1));
}
/* Indicates that audit should log the full pathname. */
#define AUDIT_NAME_FULL -1
extern int audit_match_class(int class, unsigned syscall);
extern int audit_comparator(const u32 left, const u32 op, const u32 right);
extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
extern int parent_len(const char *path);
extern int audit_compare_dname_path(const char *dname, const char *path, int plen);
extern struct sk_buff *audit_make_reply(__u32 portid, int seq, int type,
int done, int multi,
const void *payload, int size);
extern void audit_panic(const char *message);
struct audit_netlink_list {
__u32 portid;
struct net *net;
struct sk_buff_head q;
};
int audit_send_list(void *);
struct audit_net {
struct sock *nlsk;
};
extern int selinux_audit_rule_update(void);
extern struct mutex audit_filter_mutex;
extern void audit_free_rule_rcu(struct rcu_head *);
extern struct list_head audit_filter_list[];
extern struct audit_entry *audit_dupe_rule(struct audit_krule *old);
/* audit watch functions */
#ifdef CONFIG_AUDIT_WATCH
extern void audit_put_watch(struct audit_watch *watch);
extern void audit_get_watch(struct audit_watch *watch);
extern int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op);
extern int audit_add_watch(struct audit_krule *krule, struct list_head **list);
extern void audit_remove_watch_rule(struct audit_krule *krule);
extern char *audit_watch_path(struct audit_watch *watch);
extern int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev);
#else
#define audit_put_watch(w) {}
#define audit_get_watch(w) {}
#define audit_to_watch(k, p, l, o) (-EINVAL)
#define audit_add_watch(k, l) (-EINVAL)
#define audit_remove_watch_rule(k) BUG()
#define audit_watch_path(w) ""
#define audit_watch_compare(w, i, d) 0
#endif /* CONFIG_AUDIT_WATCH */
#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 const char *audit_tree_path(struct audit_tree *);
extern void audit_put_tree(struct audit_tree *);
extern void audit_kill_trees(struct list_head *);
#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 */
#define audit_kill_trees(list) BUG()
#endif
extern char *audit_unpack_string(void **, size_t *, size_t);
extern pid_t audit_sig_pid;
extern kuid_t audit_sig_uid;
extern u32 audit_sig_sid;
#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)
{
if (unlikely((audit_pid && t->tgid == audit_pid) ||
(audit_signals && !audit_dummy_context())))
return __audit_signal_info(sig, t);
return 0;
}
extern void audit_filter_inodes(struct task_struct *, struct audit_context *);
extern struct list_head *audit_killed_trees(void);
#else
#define audit_signal_info(s,t) AUDIT_DISABLED
#define audit_filter_inodes(t,c) AUDIT_DISABLED
#endif
extern struct mutex audit_cmd_mutex;