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authorTimothy Pearson <tpearson@raptorengineering.com>2017-08-23 14:45:25 -0500
committerTimothy Pearson <tpearson@raptorengineering.com>2017-08-23 14:45:25 -0500
commitfcbb27b0ec6dcbc5a5108cb8fb19eae64593d204 (patch)
tree22962a4387943edc841c72a4e636a068c66d58fd /kernel/auditfilter.c
downloadast2050-linux-kernel-fcbb27b0ec6dcbc5a5108cb8fb19eae64593d204.zip
ast2050-linux-kernel-fcbb27b0ec6dcbc5a5108cb8fb19eae64593d204.tar.gz
Initial import of modified Linux 2.6.28 tree
Original upstream URL: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y
Diffstat (limited to 'kernel/auditfilter.c')
-rw-r--r--kernel/auditfilter.c1854
1 files changed, 1854 insertions, 0 deletions
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
new file mode 100644
index 0000000..9fd85a4
--- /dev/null
+++ b/kernel/auditfilter.c
@@ -0,0 +1,1854 @@
+/* auditfilter.c -- filtering of audit events
+ *
+ * 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/kernel.h>
+#include <linux/audit.h>
+#include <linux/kthread.h>
+#include <linux/mutex.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/netlink.h>
+#include <linux/sched.h>
+#include <linux/inotify.h>
+#include <linux/security.h>
+#include "audit.h"
+
+/*
+ * Locking model:
+ *
+ * audit_filter_mutex:
+ * Synchronizes writes and blocking reads of audit's filterlist
+ * data. Rcu is used to traverse the filterlist and access
+ * contents of structs audit_entry, audit_watch and opaque
+ * LSM rules during filtering. If modified, these structures
+ * must be copied and replace their counterparts in the filterlist.
+ * An audit_parent struct is not accessed during filtering, so may
+ * be written directly provided audit_filter_mutex is held.
+ */
+
+/*
+ * Reference counting:
+ *
+ * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
+ * event. Each audit_watch holds a reference to its associated parent.
+ *
+ * audit_watch: if added to lists, lifetime is from audit_init_watch() to
+ * audit_remove_watch(). Additionally, an audit_watch may exist
+ * temporarily to assist in searching existing filter data. Each
+ * audit_krule holds a reference to its associated watch.
+ */
+
+struct audit_parent {
+ struct list_head ilist; /* entry in inotify registration list */
+ struct list_head watches; /* associated watches */
+ struct inotify_watch wdata; /* inotify watch data */
+ unsigned flags; /* status flags */
+};
+
+/*
+ * audit_parent status flags:
+ *
+ * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
+ * a filesystem event to ensure we're adding audit watches to a valid parent.
+ * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
+ * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
+ * we can receive while holding nameidata.
+ */
+#define AUDIT_PARENT_INVALID 0x001
+
+/* Audit filter lists, defined in <linux/audit.h> */
+struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
+ LIST_HEAD_INIT(audit_filter_list[0]),
+ LIST_HEAD_INIT(audit_filter_list[1]),
+ LIST_HEAD_INIT(audit_filter_list[2]),
+ LIST_HEAD_INIT(audit_filter_list[3]),
+ LIST_HEAD_INIT(audit_filter_list[4]),
+ LIST_HEAD_INIT(audit_filter_list[5]),
+#if AUDIT_NR_FILTERS != 6
+#error Fix audit_filter_list initialiser
+#endif
+};
+
+DEFINE_MUTEX(audit_filter_mutex);
+
+/* Inotify events we care about. */
+#define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
+
+void audit_free_parent(struct inotify_watch *i_watch)
+{
+ struct audit_parent *parent;
+
+ parent = container_of(i_watch, struct audit_parent, wdata);
+ WARN_ON(!list_empty(&parent->watches));
+ kfree(parent);
+}
+
+static inline void audit_get_watch(struct audit_watch *watch)
+{
+ atomic_inc(&watch->count);
+}
+
+static void audit_put_watch(struct audit_watch *watch)
+{
+ if (atomic_dec_and_test(&watch->count)) {
+ WARN_ON(watch->parent);
+ WARN_ON(!list_empty(&watch->rules));
+ kfree(watch->path);
+ kfree(watch);
+ }
+}
+
+static void audit_remove_watch(struct audit_watch *watch)
+{
+ list_del(&watch->wlist);
+ put_inotify_watch(&watch->parent->wdata);
+ watch->parent = NULL;
+ audit_put_watch(watch); /* match initial get */
+}
+
+static inline void audit_free_rule(struct audit_entry *e)
+{
+ int i;
+
+ /* some rules don't have associated watches */
+ if (e->rule.watch)
+ audit_put_watch(e->rule.watch);
+ if (e->rule.fields)
+ for (i = 0; i < e->rule.field_count; i++) {
+ struct audit_field *f = &e->rule.fields[i];
+ kfree(f->lsm_str);
+ security_audit_rule_free(f->lsm_rule);
+ }
+ kfree(e->rule.fields);
+ kfree(e->rule.filterkey);
+ kfree(e);
+}
+
+void audit_free_rule_rcu(struct rcu_head *head)
+{
+ struct audit_entry *e = container_of(head, struct audit_entry, rcu);
+ audit_free_rule(e);
+}
+
+/* Initialize a parent watch entry. */
+static struct audit_parent *audit_init_parent(struct nameidata *ndp)
+{
+ struct audit_parent *parent;
+ s32 wd;
+
+ parent = kzalloc(sizeof(*parent), GFP_KERNEL);
+ if (unlikely(!parent))
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&parent->watches);
+ parent->flags = 0;
+
+ inotify_init_watch(&parent->wdata);
+ /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
+ get_inotify_watch(&parent->wdata);
+ wd = inotify_add_watch(audit_ih, &parent->wdata,
+ ndp->path.dentry->d_inode, AUDIT_IN_WATCH);
+ if (wd < 0) {
+ audit_free_parent(&parent->wdata);
+ return ERR_PTR(wd);
+ }
+
+ return parent;
+}
+
+/* Initialize a watch entry. */
+static struct audit_watch *audit_init_watch(char *path)
+{
+ struct audit_watch *watch;
+
+ watch = kzalloc(sizeof(*watch), GFP_KERNEL);
+ if (unlikely(!watch))
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&watch->rules);
+ atomic_set(&watch->count, 1);
+ watch->path = path;
+ watch->dev = (dev_t)-1;
+ watch->ino = (unsigned long)-1;
+
+ return watch;
+}
+
+/* Initialize an audit filterlist entry. */
+static inline struct audit_entry *audit_init_entry(u32 field_count)
+{
+ struct audit_entry *entry;
+ struct audit_field *fields;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (unlikely(!entry))
+ return NULL;
+
+ fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
+ if (unlikely(!fields)) {
+ kfree(entry);
+ return NULL;
+ }
+ entry->rule.fields = fields;
+
+ return entry;
+}
+
+/* Unpack a filter field's string representation from user-space
+ * buffer. */
+char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
+{
+ char *str;
+
+ if (!*bufp || (len == 0) || (len > *remain))
+ return ERR_PTR(-EINVAL);
+
+ /* Of the currently implemented string fields, PATH_MAX
+ * defines the longest valid length.
+ */
+ if (len > PATH_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ str = kmalloc(len + 1, GFP_KERNEL);
+ if (unlikely(!str))
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(str, *bufp, len);
+ str[len] = 0;
+ *bufp += len;
+ *remain -= len;
+
+ return str;
+}
+
+/* Translate an inode field to kernel respresentation. */
+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->tree)
+ return -EINVAL;
+
+ krule->inode_f = f;
+ return 0;
+}
+
+/* Translate a watch string to kernel respresentation. */
+static int audit_to_watch(struct audit_krule *krule, char *path, int len,
+ u32 op)
+{
+ struct audit_watch *watch;
+
+ if (!audit_ih)
+ return -EOPNOTSUPP;
+
+ if (path[0] != '/' || path[len-1] == '/' ||
+ krule->listnr != AUDIT_FILTER_EXIT ||
+ op & ~AUDIT_EQUAL ||
+ krule->inode_f || krule->watch || krule->tree)
+ return -EINVAL;
+
+ watch = audit_init_watch(path);
+ if (IS_ERR(watch))
+ return PTR_ERR(watch);
+
+ audit_get_watch(watch);
+ krule->watch = watch;
+
+ return 0;
+}
+
+static __u32 *classes[AUDIT_SYSCALL_CLASSES];
+
+int __init audit_register_class(int class, unsigned *list)
+{
+ __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ while (*list != ~0U) {
+ unsigned n = *list++;
+ if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
+ kfree(p);
+ return -EINVAL;
+ }
+ p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
+ }
+ if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
+ kfree(p);
+ return -EINVAL;
+ }
+ classes[class] = p;
+ return 0;
+}
+
+int audit_match_class(int class, unsigned syscall)
+{
+ if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
+ return 0;
+ if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
+ return 0;
+ return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
+}
+
+#ifdef CONFIG_AUDITSYSCALL
+static inline int audit_match_class_bits(int class, u32 *mask)
+{
+ int i;
+
+ if (classes[class]) {
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
+ if (mask[i] & classes[class][i])
+ return 0;
+ }
+ return 1;
+}
+
+static int audit_match_signal(struct audit_entry *entry)
+{
+ struct audit_field *arch = entry->rule.arch_f;
+
+ if (!arch) {
+ /* When arch is unspecified, we must check both masks on biarch
+ * as syscall number alone is ambiguous. */
+ return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
+ entry->rule.mask) &&
+ audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
+ entry->rule.mask));
+ }
+
+ switch(audit_classify_arch(arch->val)) {
+ case 0: /* native */
+ return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
+ entry->rule.mask));
+ case 1: /* 32bit on biarch */
+ return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
+ entry->rule.mask));
+ default:
+ return 1;
+ }
+}
+#endif
+
+/* Common user-space to kernel rule translation. */
+static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
+{
+ unsigned listnr;
+ struct audit_entry *entry;
+ int i, err;
+
+ err = -EINVAL;
+ listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
+ switch(listnr) {
+ default:
+ goto exit_err;
+ case AUDIT_FILTER_USER:
+ case AUDIT_FILTER_TYPE:
+#ifdef CONFIG_AUDITSYSCALL
+ case AUDIT_FILTER_ENTRY:
+ case AUDIT_FILTER_EXIT:
+ case AUDIT_FILTER_TASK:
+#endif
+ ;
+ }
+ if (unlikely(rule->action == AUDIT_POSSIBLE)) {
+ printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
+ goto exit_err;
+ }
+ if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
+ goto exit_err;
+ if (rule->field_count > AUDIT_MAX_FIELDS)
+ goto exit_err;
+
+ err = -ENOMEM;
+ entry = audit_init_entry(rule->field_count);
+ if (!entry)
+ goto exit_err;
+
+ entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
+ entry->rule.listnr = listnr;
+ entry->rule.action = rule->action;
+ entry->rule.field_count = rule->field_count;
+
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
+ entry->rule.mask[i] = rule->mask[i];
+
+ for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
+ int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
+ __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
+ __u32 *class;
+
+ if (!(*p & AUDIT_BIT(bit)))
+ continue;
+ *p &= ~AUDIT_BIT(bit);
+ class = classes[i];
+ if (class) {
+ int j;
+ for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
+ entry->rule.mask[j] |= class[j];
+ }
+ }
+
+ return entry;
+
+exit_err:
+ return ERR_PTR(err);
+}
+
+/* Translate struct audit_rule to kernel's rule respresentation.
+ * Exists for backward compatibility with userspace. */
+static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
+{
+ struct audit_entry *entry;
+ struct audit_field *ino_f;
+ int err = 0;
+ int i;
+
+ entry = audit_to_entry_common(rule);
+ if (IS_ERR(entry))
+ goto exit_nofree;
+
+ for (i = 0; i < rule->field_count; i++) {
+ struct audit_field *f = &entry->rule.fields[i];
+
+ f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
+ f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
+ f->val = rule->values[i];
+
+ err = -EINVAL;
+ switch(f->type) {
+ default:
+ goto exit_free;
+ case AUDIT_PID:
+ case AUDIT_UID:
+ case AUDIT_EUID:
+ case AUDIT_SUID:
+ case AUDIT_FSUID:
+ case AUDIT_GID:
+ case AUDIT_EGID:
+ case AUDIT_SGID:
+ case AUDIT_FSGID:
+ case AUDIT_LOGINUID:
+ case AUDIT_PERS:
+ case AUDIT_MSGTYPE:
+ case AUDIT_PPID:
+ case AUDIT_DEVMAJOR:
+ case AUDIT_DEVMINOR:
+ case AUDIT_EXIT:
+ case AUDIT_SUCCESS:
+ /* bit ops are only useful on syscall args */
+ if (f->op == AUDIT_BIT_MASK ||
+ f->op == AUDIT_BIT_TEST) {
+ err = -EINVAL;
+ goto exit_free;
+ }
+ break;
+ case AUDIT_ARG0:
+ case AUDIT_ARG1:
+ case AUDIT_ARG2:
+ case AUDIT_ARG3:
+ break;
+ /* arch is only allowed to be = or != */
+ case AUDIT_ARCH:
+ if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
+ && (f->op != AUDIT_NEGATE) && (f->op)) {
+ err = -EINVAL;
+ goto exit_free;
+ }
+ entry->rule.arch_f = f;
+ break;
+ case AUDIT_PERM:
+ if (f->val & ~15)
+ goto exit_free;
+ break;
+ case AUDIT_FILETYPE:
+ if ((f->val & ~S_IFMT) > S_IFMT)
+ goto exit_free;
+ break;
+ case AUDIT_INODE:
+ err = audit_to_inode(&entry->rule, f);
+ if (err)
+ goto exit_free;
+ break;
+ }
+
+ entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
+
+ /* Support for legacy operators where
+ * AUDIT_NEGATE bit signifies != and otherwise assumes == */
+ if (f->op & AUDIT_NEGATE)
+ f->op = AUDIT_NOT_EQUAL;
+ else if (!f->op)
+ f->op = AUDIT_EQUAL;
+ else if (f->op == AUDIT_OPERATORS) {
+ err = -EINVAL;
+ goto exit_free;
+ }
+ }
+
+ ino_f = entry->rule.inode_f;
+ if (ino_f) {
+ switch(ino_f->op) {
+ case AUDIT_NOT_EQUAL:
+ entry->rule.inode_f = NULL;
+ case AUDIT_EQUAL:
+ break;
+ default:
+ err = -EINVAL;
+ goto exit_free;
+ }
+ }
+
+exit_nofree:
+ return entry;
+
+exit_free:
+ audit_free_rule(entry);
+ return ERR_PTR(err);
+}
+
+/* Translate struct audit_rule_data to kernel's rule respresentation. */
+static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
+ size_t datasz)
+{
+ int err = 0;
+ struct audit_entry *entry;
+ struct audit_field *ino_f;
+ void *bufp;
+ size_t remain = datasz - sizeof(struct audit_rule_data);
+ int i;
+ char *str;
+
+ entry = audit_to_entry_common((struct audit_rule *)data);
+ if (IS_ERR(entry))
+ goto exit_nofree;
+
+ bufp = data->buf;
+ entry->rule.vers_ops = 2;
+ for (i = 0; i < data->field_count; i++) {
+ struct audit_field *f = &entry->rule.fields[i];
+
+ err = -EINVAL;
+ if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
+ data->fieldflags[i] & ~AUDIT_OPERATORS)
+ goto exit_free;
+
+ f->op = data->fieldflags[i] & AUDIT_OPERATORS;
+ f->type = data->fields[i];
+ f->val = data->values[i];
+ f->lsm_str = NULL;
+ f->lsm_rule = NULL;
+ switch(f->type) {
+ case AUDIT_PID:
+ case AUDIT_UID:
+ case AUDIT_EUID:
+ case AUDIT_SUID:
+ case AUDIT_FSUID:
+ case AUDIT_GID:
+ case AUDIT_EGID:
+ case AUDIT_SGID:
+ case AUDIT_FSGID:
+ case AUDIT_LOGINUID:
+ case AUDIT_PERS:
+ case AUDIT_MSGTYPE:
+ case AUDIT_PPID:
+ case AUDIT_DEVMAJOR:
+ case AUDIT_DEVMINOR:
+ case AUDIT_EXIT:
+ case AUDIT_SUCCESS:
+ case AUDIT_ARG0:
+ case AUDIT_ARG1:
+ case AUDIT_ARG2:
+ case AUDIT_ARG3:
+ break;
+ case AUDIT_ARCH:
+ entry->rule.arch_f = f;
+ break;
+ case AUDIT_SUBJ_USER:
+ case AUDIT_SUBJ_ROLE:
+ case AUDIT_SUBJ_TYPE:
+ case AUDIT_SUBJ_SEN:
+ case AUDIT_SUBJ_CLR:
+ case AUDIT_OBJ_USER:
+ case AUDIT_OBJ_ROLE:
+ case AUDIT_OBJ_TYPE:
+ case AUDIT_OBJ_LEV_LOW:
+ case AUDIT_OBJ_LEV_HIGH:
+ str = audit_unpack_string(&bufp, &remain, f->val);
+ if (IS_ERR(str))
+ goto exit_free;
+ entry->rule.buflen += f->val;
+
+ err = security_audit_rule_init(f->type, f->op, str,
+ (void **)&f->lsm_rule);
+ /* Keep currently invalid fields around in case they
+ * become valid after a policy reload. */
+ if (err == -EINVAL) {
+ printk(KERN_WARNING "audit rule for LSM "
+ "\'%s\' is invalid\n", str);
+ err = 0;
+ }
+ if (err) {
+ kfree(str);
+ goto exit_free;
+ } else
+ f->lsm_str = str;
+ break;
+ case AUDIT_WATCH:
+ str = audit_unpack_string(&bufp, &remain, f->val);
+ if (IS_ERR(str))
+ goto exit_free;
+ entry->rule.buflen += f->val;
+
+ err = audit_to_watch(&entry->rule, str, f->val, f->op);
+ if (err) {
+ kfree(str);
+ 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)
+ goto exit_free;
+ break;
+ case AUDIT_FILTERKEY:
+ err = -EINVAL;
+ if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
+ goto exit_free;
+ str = audit_unpack_string(&bufp, &remain, f->val);
+ if (IS_ERR(str))
+ goto exit_free;
+ entry->rule.buflen += f->val;
+ entry->rule.filterkey = str;
+ break;
+ case AUDIT_PERM:
+ if (f->val & ~15)
+ goto exit_free;
+ break;
+ case AUDIT_FILETYPE:
+ if ((f->val & ~S_IFMT) > S_IFMT)
+ goto exit_free;
+ break;
+ default:
+ goto exit_free;
+ }
+ }
+
+ ino_f = entry->rule.inode_f;
+ if (ino_f) {
+ switch(ino_f->op) {
+ case AUDIT_NOT_EQUAL:
+ entry->rule.inode_f = NULL;
+ case AUDIT_EQUAL:
+ break;
+ default:
+ err = -EINVAL;
+ goto exit_free;
+ }
+ }
+
+exit_nofree:
+ return entry;
+
+exit_free:
+ audit_free_rule(entry);
+ return ERR_PTR(err);
+}
+
+/* Pack a filter field's string representation into data block. */
+static inline size_t audit_pack_string(void **bufp, const char *str)
+{
+ size_t len = strlen(str);
+
+ memcpy(*bufp, str, len);
+ *bufp += len;
+
+ return len;
+}
+
+/* Translate kernel rule respresentation to struct audit_rule.
+ * Exists for backward compatibility with userspace. */
+static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
+{
+ struct audit_rule *rule;
+ int i;
+
+ rule = kzalloc(sizeof(*rule), GFP_KERNEL);
+ if (unlikely(!rule))
+ return NULL;
+
+ rule->flags = krule->flags | krule->listnr;
+ rule->action = krule->action;
+ rule->field_count = krule->field_count;
+ for (i = 0; i < rule->field_count; i++) {
+ rule->values[i] = krule->fields[i].val;
+ rule->fields[i] = krule->fields[i].type;
+
+ if (krule->vers_ops == 1) {
+ if (krule->fields[i].op & AUDIT_NOT_EQUAL)
+ rule->fields[i] |= AUDIT_NEGATE;
+ } else {
+ rule->fields[i] |= krule->fields[i].op;
+ }
+ }
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
+
+ return rule;
+}
+
+/* Translate kernel rule respresentation to struct audit_rule_data. */
+static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
+{
+ struct audit_rule_data *data;
+ void *bufp;
+ int i;
+
+ data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
+ if (unlikely(!data))
+ return NULL;
+ memset(data, 0, sizeof(*data));
+
+ data->flags = krule->flags | krule->listnr;
+ data->action = krule->action;
+ data->field_count = krule->field_count;
+ bufp = data->buf;
+ for (i = 0; i < data->field_count; i++) {
+ struct audit_field *f = &krule->fields[i];
+
+ data->fields[i] = f->type;
+ data->fieldflags[i] = f->op;
+ switch(f->type) {
+ case AUDIT_SUBJ_USER:
+ case AUDIT_SUBJ_ROLE:
+ case AUDIT_SUBJ_TYPE:
+ case AUDIT_SUBJ_SEN:
+ case AUDIT_SUBJ_CLR:
+ case AUDIT_OBJ_USER:
+ case AUDIT_OBJ_ROLE:
+ case AUDIT_OBJ_TYPE:
+ case AUDIT_OBJ_LEV_LOW:
+ case AUDIT_OBJ_LEV_HIGH:
+ data->buflen += data->values[i] =
+ audit_pack_string(&bufp, f->lsm_str);
+ break;
+ case AUDIT_WATCH:
+ 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);
+ break;
+ default:
+ data->values[i] = f->val;
+ }
+ }
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
+
+ return data;
+}
+
+/* Compare two rules in kernel format. Considered success if rules
+ * don't match. */
+static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
+{
+ int i;
+
+ if (a->flags != b->flags ||
+ a->listnr != b->listnr ||
+ a->action != b->action ||
+ a->field_count != b->field_count)
+ return 1;
+
+ for (i = 0; i < a->field_count; i++) {
+ if (a->fields[i].type != b->fields[i].type ||
+ a->fields[i].op != b->fields[i].op)
+ return 1;
+
+ switch(a->fields[i].type) {
+ case AUDIT_SUBJ_USER:
+ case AUDIT_SUBJ_ROLE:
+ case AUDIT_SUBJ_TYPE:
+ case AUDIT_SUBJ_SEN:
+ case AUDIT_SUBJ_CLR:
+ case AUDIT_OBJ_USER:
+ case AUDIT_OBJ_ROLE:
+ case AUDIT_OBJ_TYPE:
+ case AUDIT_OBJ_LEV_LOW:
+ case AUDIT_OBJ_LEV_HIGH:
+ if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
+ return 1;
+ break;
+ case AUDIT_WATCH:
+ 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))
+ return 1;
+ break;
+ default:
+ if (a->fields[i].val != b->fields[i].val)
+ return 1;
+ }
+ }
+
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
+ if (a->mask[i] != b->mask[i])
+ return 1;
+
+ return 0;
+}
+
+/* Duplicate the given audit watch. The new watch's rules list is initialized
+ * to an empty list and wlist is undefined. */
+static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
+{
+ char *path;
+ struct audit_watch *new;
+
+ path = kstrdup(old->path, GFP_KERNEL);
+ if (unlikely(!path))
+ return ERR_PTR(-ENOMEM);
+
+ new = audit_init_watch(path);
+ if (IS_ERR(new)) {
+ kfree(path);
+ goto out;
+ }
+
+ new->dev = old->dev;
+ new->ino = old->ino;
+ get_inotify_watch(&old->parent->wdata);
+ new->parent = old->parent;
+
+out:
+ return new;
+}
+
+/* Duplicate LSM field information. The lsm_rule is opaque, so must be
+ * re-initialized. */
+static inline int audit_dupe_lsm_field(struct audit_field *df,
+ struct audit_field *sf)
+{
+ int ret = 0;
+ char *lsm_str;
+
+ /* our own copy of lsm_str */
+ lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
+ if (unlikely(!lsm_str))
+ return -ENOMEM;
+ df->lsm_str = lsm_str;
+
+ /* our own (refreshed) copy of lsm_rule */
+ ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
+ (void **)&df->lsm_rule);
+ /* Keep currently invalid fields around in case they
+ * become valid after a policy reload. */
+ if (ret == -EINVAL) {
+ printk(KERN_WARNING "audit rule for LSM \'%s\' is "
+ "invalid\n", df->lsm_str);
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/* Duplicate an audit rule. This will be a deep copy with the exception
+ * of the watch - that pointer is carried over. The LSM specific fields
+ * will be updated in the copy. The point is to be able to replace the old
+ * rule with the new rule in the filterlist, then free the old rule.
+ * The rlist element is undefined; list manipulations are handled apart from
+ * the initial copy. */
+static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
+ struct audit_watch *watch)
+{
+ u32 fcount = old->field_count;
+ struct audit_entry *entry;
+ struct audit_krule *new;
+ char *fk;
+ int i, err = 0;
+
+ entry = audit_init_entry(fcount);
+ if (unlikely(!entry))
+ return ERR_PTR(-ENOMEM);
+
+ new = &entry->rule;
+ new->vers_ops = old->vers_ops;
+ new->flags = old->flags;
+ new->listnr = old->listnr;
+ new->action = old->action;
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
+ new->mask[i] = old->mask[i];
+ new->buflen = old->buflen;
+ 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 lsm_rule fields, because
+ * the originals will all be freed when the old rule is freed. */
+ for (i = 0; i < fcount; i++) {
+ switch (new->fields[i].type) {
+ case AUDIT_SUBJ_USER:
+ case AUDIT_SUBJ_ROLE:
+ case AUDIT_SUBJ_TYPE:
+ case AUDIT_SUBJ_SEN:
+ case AUDIT_SUBJ_CLR:
+ case AUDIT_OBJ_USER:
+ case AUDIT_OBJ_ROLE:
+ case AUDIT_OBJ_TYPE:
+ case AUDIT_OBJ_LEV_LOW:
+ case AUDIT_OBJ_LEV_HIGH:
+ err = audit_dupe_lsm_field(&new->fields[i],
+ &old->fields[i]);
+ break;
+ case AUDIT_FILTERKEY:
+ fk = kstrdup(old->filterkey, GFP_KERNEL);
+ if (unlikely(!fk))
+ err = -ENOMEM;
+ else
+ new->filterkey = fk;
+ }
+ if (err) {
+ audit_free_rule(entry);
+ return ERR_PTR(err);
+ }
+ }
+
+ if (watch) {
+ audit_get_watch(watch);
+ new->watch = watch;
+ }
+
+ return entry;
+}
+
+/* Update inode info in audit rules based on filesystem event. */
+static void audit_update_watch(struct audit_parent *parent,
+ const char *dname, dev_t dev,
+ unsigned long ino, unsigned invalidating)
+{
+ struct audit_watch *owatch, *nwatch, *nextw;
+ struct audit_krule *r, *nextr;
+ struct audit_entry *oentry, *nentry;
+
+ mutex_lock(&audit_filter_mutex);
+ list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
+ if (audit_compare_dname_path(dname, owatch->path, NULL))
+ continue;
+
+ /* If the update involves invalidating rules, do the inode-based
+ * filtering now, so we don't omit records. */
+ if (invalidating && current->audit_context &&
+ audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
+ audit_set_auditable(current->audit_context);
+
+ nwatch = audit_dupe_watch(owatch);
+ if (IS_ERR(nwatch)) {
+ mutex_unlock(&audit_filter_mutex);
+ audit_panic("error updating watch, skipping");
+ return;
+ }
+ nwatch->dev = dev;
+ nwatch->ino = ino;
+
+ list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
+
+ oentry = container_of(r, struct audit_entry, rule);
+ list_del(&oentry->rule.rlist);
+ list_del_rcu(&oentry->list);
+
+ nentry = audit_dupe_rule(&oentry->rule, nwatch);
+ if (IS_ERR(nentry))
+ audit_panic("error updating watch, removing");
+ else {
+ int h = audit_hash_ino((u32)ino);
+ list_add(&nentry->rule.rlist, &nwatch->rules);
+ list_add_rcu(&nentry->list, &audit_inode_hash[h]);
+ }
+
+ call_rcu(&oentry->rcu, audit_free_rule_rcu);
+ }
+
+ if (audit_enabled) {
+ struct audit_buffer *ab;
+ ab = audit_log_start(NULL, GFP_KERNEL,
+ AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, "auid=%u ses=%u",
+ audit_get_loginuid(current),
+ audit_get_sessionid(current));
+ audit_log_format(ab,
+ " op=updated rules specifying path=");
+ audit_log_untrustedstring(ab, owatch->path);
+ audit_log_format(ab, " with dev=%u ino=%lu\n",
+ dev, ino);
+ audit_log_format(ab, " list=%d res=1", r->listnr);
+ audit_log_end(ab);
+ }
+ audit_remove_watch(owatch);
+ goto add_watch_to_parent; /* event applies to a single watch */
+ }
+ mutex_unlock(&audit_filter_mutex);
+ return;
+
+add_watch_to_parent:
+ list_add(&nwatch->wlist, &parent->watches);
+ mutex_unlock(&audit_filter_mutex);
+ return;
+}
+
+/* Remove all watches & rules associated with a parent that is going away. */
+static void audit_remove_parent_watches(struct audit_parent *parent)
+{
+ struct audit_watch *w, *nextw;
+ struct audit_krule *r, *nextr;
+ struct audit_entry *e;
+
+ mutex_lock(&audit_filter_mutex);
+ parent->flags |= AUDIT_PARENT_INVALID;
+ list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
+ list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
+ e = container_of(r, struct audit_entry, rule);
+ if (audit_enabled) {
+ struct audit_buffer *ab;
+ ab = audit_log_start(NULL, GFP_KERNEL,
+ AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, "auid=%u ses=%u",
+ audit_get_loginuid(current),
+ audit_get_sessionid(current));
+ audit_log_format(ab, " op=remove rule path=");
+ audit_log_untrustedstring(ab, w->path);
+ if (r->filterkey) {
+ audit_log_format(ab, " key=");
+ audit_log_untrustedstring(ab,
+ r->filterkey);
+ } else
+ audit_log_format(ab, " key=(null)");
+ audit_log_format(ab, " list=%d res=1",
+ r->listnr);
+ audit_log_end(ab);
+ }
+ list_del(&r->rlist);
+ list_del_rcu(&e->list);
+ call_rcu(&e->rcu, audit_free_rule_rcu);
+ }
+ audit_remove_watch(w);
+ }
+ mutex_unlock(&audit_filter_mutex);
+}
+
+/* Unregister inotify watches for parents on in_list.
+ * Generates an IN_IGNORED event. */
+static void audit_inotify_unregister(struct list_head *in_list)
+{
+ struct audit_parent *p, *n;
+
+ list_for_each_entry_safe(p, n, in_list, ilist) {
+ list_del(&p->ilist);
+ inotify_rm_watch(audit_ih, &p->wdata);
+ /* the unpin matching the pin in audit_do_del_rule() */
+ unpin_inotify_watch(&p->wdata);
+ }
+}
+
+/* Find an existing audit rule.
+ * Caller must hold audit_filter_mutex to prevent stale rule data. */
+static struct audit_entry *audit_find_rule(struct audit_entry *entry,
+ struct list_head *list)
+{
+ struct audit_entry *e, *found = NULL;
+ int h;
+
+ if (entry->rule.watch) {
+ /* we don't know the inode number, so must walk entire hash */
+ for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
+ list = &audit_inode_hash[h];
+ list_for_each_entry(e, list, list)
+ if (!audit_compare_rule(&entry->rule, &e->rule)) {
+ found = e;
+ goto out;
+ }
+ }
+ goto out;
+ }
+
+ list_for_each_entry(e, list, list)
+ if (!audit_compare_rule(&entry->rule, &e->rule)) {
+ found = e;
+ goto out;
+ }
+
+out:
+ return found;
+}
+
+/* Get path information necessary for adding watches. */
+static int audit_get_nd(char *path, struct nameidata **ndp,
+ struct nameidata **ndw)
+{
+ struct nameidata *ndparent, *ndwatch;
+ int err;
+
+ ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
+ if (unlikely(!ndparent))
+ return -ENOMEM;
+
+ ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
+ if (unlikely(!ndwatch)) {
+ kfree(ndparent);
+ return -ENOMEM;
+ }
+
+ err = path_lookup(path, LOOKUP_PARENT, ndparent);
+ if (err) {
+ kfree(ndparent);
+ kfree(ndwatch);
+ return err;
+ }
+
+ err = path_lookup(path, 0, ndwatch);
+ if (err) {
+ kfree(ndwatch);
+ ndwatch = NULL;
+ }
+
+ *ndp = ndparent;
+ *ndw = ndwatch;
+
+ return 0;
+}
+
+/* Release resources used for watch path information. */
+static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
+{
+ if (ndp) {
+ path_put(&ndp->path);
+ kfree(ndp);
+ }
+ if (ndw) {
+ path_put(&ndw->path);
+ kfree(ndw);
+ }
+}
+
+/* Associate the given rule with an existing parent inotify_watch.
+ * Caller must hold audit_filter_mutex. */
+static void audit_add_to_parent(struct audit_krule *krule,
+ struct audit_parent *parent)
+{
+ struct audit_watch *w, *watch = krule->watch;
+ int watch_found = 0;
+
+ list_for_each_entry(w, &parent->watches, wlist) {
+ if (strcmp(watch->path, w->path))
+ continue;
+
+ watch_found = 1;
+
+ /* put krule's and initial refs to temporary watch */
+ audit_put_watch(watch);
+ audit_put_watch(watch);
+
+ audit_get_watch(w);
+ krule->watch = watch = w;
+ break;
+ }
+
+ if (!watch_found) {
+ get_inotify_watch(&parent->wdata);
+ watch->parent = parent;
+
+ list_add(&watch->wlist, &parent->watches);
+ }
+ list_add(&krule->rlist, &watch->rules);
+}
+
+/* Find a matching watch entry, or add this one.
+ * Caller must hold audit_filter_mutex. */
+static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
+ struct nameidata *ndw)
+{
+ struct audit_watch *watch = krule->watch;
+ struct inotify_watch *i_watch;
+ struct audit_parent *parent;
+ int ret = 0;
+
+ /* update watch filter fields */
+ if (ndw) {
+ watch->dev = ndw->path.dentry->d_inode->i_sb->s_dev;
+ watch->ino = ndw->path.dentry->d_inode->i_ino;
+ }
+
+ /* The audit_filter_mutex must not be held during inotify calls because
+ * we hold it during inotify event callback processing. If an existing
+ * inotify watch is found, inotify_find_watch() grabs a reference before
+ * returning.
+ */
+ mutex_unlock(&audit_filter_mutex);
+
+ if (inotify_find_watch(audit_ih, ndp->path.dentry->d_inode,
+ &i_watch) < 0) {
+ parent = audit_init_parent(ndp);
+ if (IS_ERR(parent)) {
+ /* caller expects mutex locked */
+ mutex_lock(&audit_filter_mutex);
+ return PTR_ERR(parent);
+ }
+ } else
+ parent = container_of(i_watch, struct audit_parent, wdata);
+
+ mutex_lock(&audit_filter_mutex);
+
+ /* parent was moved before we took audit_filter_mutex */
+ if (parent->flags & AUDIT_PARENT_INVALID)
+ ret = -ENOENT;
+ else
+ audit_add_to_parent(krule, parent);
+
+ /* match get in audit_init_parent or inotify_find_watch */
+ put_inotify_watch(&parent->wdata);
+ return ret;
+}
+
+/* Add rule to given filterlist if not a duplicate. */
+static inline int audit_add_rule(struct audit_entry *entry,
+ struct list_head *list)
+{
+ 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
+ int dont_count = 0;
+
+ /* If either of these, don't count towards total */
+ if (entry->rule.listnr == AUDIT_FILTER_USER ||
+ entry->rule.listnr == AUDIT_FILTER_TYPE)
+ dont_count = 1;
+#endif
+
+ if (inode_f) {
+ h = audit_hash_ino(inode_f->val);
+ list = &audit_inode_hash[h];
+ }
+
+ mutex_lock(&audit_filter_mutex);
+ e = audit_find_rule(entry, list);
+ 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;
+ }
+
+ /* Avoid calling path_lookup under audit_filter_mutex. */
+ if (watch) {
+ err = audit_get_nd(watch->path, &ndp, &ndw);
+ if (err)
+ goto error;
+ }
+
+ mutex_lock(&audit_filter_mutex);
+ if (watch) {
+ /* audit_filter_mutex is dropped and re-taken during this call */
+ err = audit_add_watch(&entry->rule, ndp, ndw);
+ if (err) {
+ mutex_unlock(&audit_filter_mutex);
+ goto error;
+ }
+ 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);
+ entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
+ } else {
+ list_add_tail_rcu(&entry->list, list);
+ }
+#ifdef CONFIG_AUDITSYSCALL
+ if (!dont_count)
+ audit_n_rules++;
+
+ if (!audit_match_signal(entry))
+ audit_signals++;
+#endif
+ mutex_unlock(&audit_filter_mutex);
+
+ audit_put_nd(ndp, ndw); /* NULL args OK */
+ return 0;
+
+error:
+ audit_put_nd(ndp, ndw); /* NULL args OK */
+ if (watch)
+ audit_put_watch(watch); /* tmp watch, matches initial get */
+ return err;
+}
+
+/* Remove an existing rule from filterlist. */
+static inline int audit_del_rule(struct audit_entry *entry,
+ struct list_head *list)
+{
+ 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
+ int dont_count = 0;
+
+ /* If either of these, don't count towards total */
+ if (entry->rule.listnr == AUDIT_FILTER_USER ||
+ entry->rule.listnr == AUDIT_FILTER_TYPE)
+ dont_count = 1;
+#endif
+
+ if (inode_f) {
+ h = audit_hash_ino(inode_f->val);
+ list = &audit_inode_hash[h];
+ }
+
+ mutex_lock(&audit_filter_mutex);
+ e = audit_find_rule(entry, list);
+ if (!e) {
+ mutex_unlock(&audit_filter_mutex);
+ ret = -ENOENT;
+ goto out;
+ }
+
+ watch = e->rule.watch;
+ if (watch) {
+ struct audit_parent *parent = watch->parent;
+
+ list_del(&e->rule.rlist);
+
+ if (list_empty(&watch->rules)) {
+ audit_remove_watch(watch);
+
+ if (list_empty(&parent->watches)) {
+ /* Put parent on the inotify un-registration
+ * list. Grab a reference before releasing
+ * audit_filter_mutex, to be released in
+ * audit_inotify_unregister().
+ * If filesystem is going away, just leave
+ * the sucker alone, eviction will take
+ * care of it.
+ */
+ if (pin_inotify_watch(&parent->wdata))
+ list_add(&parent->ilist, &inotify_list);
+ }
+ }
+ }
+
+ if (e->rule.tree)
+ audit_remove_tree_rule(&e->rule);
+
+ list_del_rcu(&e->list);
+ call_rcu(&e->rcu, audit_free_rule_rcu);
+
+#ifdef CONFIG_AUDITSYSCALL
+ if (!dont_count)
+ audit_n_rules--;
+
+ if (!audit_match_signal(entry))
+ audit_signals--;
+#endif
+ mutex_unlock(&audit_filter_mutex);
+
+ if (!list_empty(&inotify_list))
+ audit_inotify_unregister(&inotify_list);
+
+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;
+}
+
+/* List rules using struct audit_rule. Exists for backward
+ * compatibility with userspace. */
+static void audit_list(int pid, int seq, struct sk_buff_head *q)
+{
+ struct sk_buff *skb;
+ struct audit_entry *entry;
+ int i;
+
+ /* This is a blocking read, so use audit_filter_mutex instead of rcu
+ * iterator to sync with list writers. */
+ for (i=0; i<AUDIT_NR_FILTERS; i++) {
+ list_for_each_entry(entry, &audit_filter_list[i], list) {
+ struct audit_rule *rule;
+
+ rule = audit_krule_to_rule(&entry->rule);
+ if (unlikely(!rule))
+ break;
+ skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
+ rule, sizeof(*rule));
+ if (skb)
+ skb_queue_tail(q, skb);
+ kfree(rule);
+ }
+ }
+ for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
+ list_for_each_entry(entry, &audit_inode_hash[i], list) {
+ struct audit_rule *rule;
+
+ rule = audit_krule_to_rule(&entry->rule);
+ if (unlikely(!rule))
+ break;
+ skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
+ rule, sizeof(*rule));
+ if (skb)
+ skb_queue_tail(q, skb);
+ kfree(rule);
+ }
+ }
+ skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
+ if (skb)
+ skb_queue_tail(q, skb);
+}
+
+/* List rules using struct audit_rule_data. */
+static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
+{
+ struct sk_buff *skb;
+ struct audit_entry *e;
+ int i;
+
+ /* This is a blocking read, so use audit_filter_mutex instead of rcu
+ * iterator to sync with list writers. */
+ for (i=0; i<AUDIT_NR_FILTERS; i++) {
+ list_for_each_entry(e, &audit_filter_list[i], list) {
+ struct audit_rule_data *data;
+
+ data = audit_krule_to_data(&e->rule);
+ if (unlikely(!data))
+ break;
+ skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
+ data, sizeof(*data) + data->buflen);
+ if (skb)
+ skb_queue_tail(q, skb);
+ kfree(data);
+ }
+ }
+ for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
+ list_for_each_entry(e, &audit_inode_hash[i], list) {
+ struct audit_rule_data *data;
+
+ data = audit_krule_to_data(&e->rule);
+ if (unlikely(!data))
+ break;
+ skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
+ data, sizeof(*data) + data->buflen);
+ if (skb)
+ skb_queue_tail(q, skb);
+ kfree(data);
+ }
+ }
+ skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
+ if (skb)
+ skb_queue_tail(q, skb);
+}
+
+/* Log rule additions and removals */
+static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid,
+ char *action, struct audit_krule *rule,
+ int res)
+{
+ struct audit_buffer *ab;
+
+ if (!audit_enabled)
+ return;
+
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ if (!ab)
+ return;
+ audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid);
+ if (sid) {
+ char *ctx = NULL;
+ u32 len;
+ if (security_secid_to_secctx(sid, &ctx, &len))
+ audit_log_format(ab, " ssid=%u", sid);
+ else {
+ audit_log_format(ab, " subj=%s", ctx);
+ security_release_secctx(ctx, len);
+ }
+ }
+ audit_log_format(ab, " op=%s rule key=", action);
+ if (rule->filterkey)
+ audit_log_untrustedstring(ab, rule->filterkey);
+ else
+ audit_log_format(ab, "(null)");
+ audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
+ audit_log_end(ab);
+}
+
+/**
+ * audit_receive_filter - apply all rules to the specified message type
+ * @type: audit message type
+ * @pid: target pid for netlink audit messages
+ * @uid: target uid for netlink audit messages
+ * @seq: netlink audit message sequence (serial) number
+ * @data: payload data
+ * @datasz: size of payload data
+ * @loginuid: loginuid of sender
+ * @sessionid: sessionid for netlink audit message
+ * @sid: SE Linux Security ID of sender
+ */
+int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
+ size_t datasz, uid_t loginuid, u32 sessionid, u32 sid)
+{
+ struct task_struct *tsk;
+ struct audit_netlink_list *dest;
+ int err = 0;
+ struct audit_entry *entry;
+
+ switch (type) {
+ case AUDIT_LIST:
+ case AUDIT_LIST_RULES:
+ /* We can't just spew out the rules here because we might fill
+ * the available socket buffer space and deadlock waiting for
+ * auditctl to read from it... which isn't ever going to
+ * happen if we're actually running in the context of auditctl
+ * trying to _send_ the stuff */
+
+ dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
+ if (!dest)
+ return -ENOMEM;
+ dest->pid = pid;
+ skb_queue_head_init(&dest->q);
+
+ mutex_lock(&audit_filter_mutex);
+ if (type == AUDIT_LIST)
+ audit_list(pid, seq, &dest->q);
+ else
+ audit_list_rules(pid, seq, &dest->q);
+ mutex_unlock(&audit_filter_mutex);
+
+ tsk = kthread_run(audit_send_list, dest, "audit_send_list");
+ if (IS_ERR(tsk)) {
+ skb_queue_purge(&dest->q);
+ kfree(dest);
+ err = PTR_ERR(tsk);
+ }
+ break;
+ case AUDIT_ADD:
+ case AUDIT_ADD_RULE:
+ if (type == AUDIT_ADD)
+ entry = audit_rule_to_entry(data);
+ else
+ entry = audit_data_to_entry(data, datasz);
+ if (IS_ERR(entry))
+ return PTR_ERR(entry);
+
+ err = audit_add_rule(entry,
+ &audit_filter_list[entry->rule.listnr]);
+ audit_log_rule_change(loginuid, sessionid, sid, "add",
+ &entry->rule, !err);
+
+ if (err)
+ audit_free_rule(entry);
+ break;
+ case AUDIT_DEL:
+ case AUDIT_DEL_RULE:
+ if (type == AUDIT_DEL)
+ entry = audit_rule_to_entry(data);
+ else
+ entry = audit_data_to_entry(data, datasz);
+ if (IS_ERR(entry))
+ return PTR_ERR(entry);
+
+ err = audit_del_rule(entry,
+ &audit_filter_list[entry->rule.listnr]);
+ audit_log_rule_change(loginuid, sessionid, sid, "remove",
+ &entry->rule, !err);
+
+ audit_free_rule(entry);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return err;
+}
+
+int audit_comparator(const u32 left, const u32 op, const u32 right)
+{
+ switch (op) {
+ case AUDIT_EQUAL:
+ return (left == right);
+ case AUDIT_NOT_EQUAL:
+ return (left != right);
+ case AUDIT_LESS_THAN:
+ return (left < right);
+ case AUDIT_LESS_THAN_OR_EQUAL:
+ return (left <= right);
+ case AUDIT_GREATER_THAN:
+ return (left > right);
+ case AUDIT_GREATER_THAN_OR_EQUAL:
+ return (left >= right);
+ case AUDIT_BIT_MASK:
+ return (left & right);
+ case AUDIT_BIT_TEST:
+ return ((left & right) == right);
+ }
+ BUG();
+ return 0;
+}
+
+/* Compare given dentry name with last component in given path,
+ * return of 0 indicates a match. */
+int audit_compare_dname_path(const char *dname, const char *path,
+ int *dirlen)
+{
+ int dlen, plen;
+ const char *p;
+
+ if (!dname || !path)
+ return 1;
+
+ dlen = strlen(dname);
+ plen = strlen(path);
+ if (plen < dlen)
+ return 1;
+
+ /* disregard trailing slashes */
+ p = path + plen - 1;
+ while ((*p == '/') && (p > path))
+ p--;
+
+ /* find last path component */
+ p = p - dlen + 1;
+ if (p < path)
+ return 1;
+ else if (p > path) {
+ if (*--p != '/')
+ return 1;
+ else
+ p++;
+ }
+
+ /* return length of path's directory component */
+ if (dirlen)
+ *dirlen = p - path;
+ return strncmp(p, dname, dlen);
+}
+
+static int audit_filter_user_rules(struct netlink_skb_parms *cb,
+ struct audit_krule *rule,
+ enum audit_state *state)
+{
+ int i;
+
+ for (i = 0; i < rule->field_count; i++) {
+ struct audit_field *f = &rule->fields[i];
+ int result = 0;
+
+ switch (f->type) {
+ case AUDIT_PID:
+ result = audit_comparator(cb->creds.pid, f->op, f->val);
+ break;
+ case AUDIT_UID:
+ result = audit_comparator(cb->creds.uid, f->op, f->val);
+ break;
+ case AUDIT_GID:
+ result = audit_comparator(cb->creds.gid, f->op, f->val);
+ break;
+ case AUDIT_LOGINUID:
+ result = audit_comparator(cb->loginuid, f->op, f->val);
+ break;
+ }
+
+ if (!result)
+ return 0;
+ }
+ switch (rule->action) {
+ case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
+ case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
+ }
+ return 1;
+}
+
+int audit_filter_user(struct netlink_skb_parms *cb)
+{
+ enum audit_state state = AUDIT_DISABLED;
+ struct audit_entry *e;
+ int ret = 1;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
+ if (audit_filter_user_rules(cb, &e->rule, &state)) {
+ if (state == AUDIT_DISABLED)
+ ret = 0;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return ret; /* Audit by default */
+}
+
+int audit_filter_type(int type)
+{
+ struct audit_entry *e;
+ int result = 0;
+
+ rcu_read_lock();
+ if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
+ goto unlock_and_return;
+
+ list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
+ list) {
+ int i;
+ for (i = 0; i < e->rule.field_count; i++) {
+ struct audit_field *f = &e->rule.fields[i];
+ if (f->type == AUDIT_MSGTYPE) {
+ result = audit_comparator(type, f->op, f->val);
+ if (!result)
+ break;
+ }
+ }
+ if (result)
+ goto unlock_and_return;
+ }
+unlock_and_return:
+ rcu_read_unlock();
+ return result;
+}
+
+/* This function will re-initialize the lsm_rule field of all applicable rules.
+ * It will traverse the filter lists serarching for rules that contain LSM
+ * specific filter fields. When such a rule is found, it is copied, the
+ * LSM field is re-initialized, and the old rule is replaced with the
+ * updated rule. */
+int audit_update_lsm_rules(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 */
+ mutex_lock(&audit_filter_mutex);
+
+ for (i = 0; i < AUDIT_NR_FILTERS; i++) {
+ list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
+ if (!security_audit_rule_known(&entry->rule))
+ continue;
+
+ watch = entry->rule.watch;
+ tree = entry->rule.tree;
+ nentry = audit_dupe_rule(&entry->rule, watch);
+ if (IS_ERR(nentry)) {
+ /* save the first error encountered for the
+ * return value */
+ if (!err)
+ err = PTR_ERR(nentry);
+ audit_panic("error updating LSM filters");
+ if (watch)
+ list_del(&entry->rule.rlist);
+ list_del_rcu(&entry->list);
+ } else {
+ if (watch) {
+ 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);
+ }
+ }
+
+ mutex_unlock(&audit_filter_mutex);
+
+ return err;
+}
+
+/* Update watch data in audit rules based on inotify events. */
+void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
+ u32 cookie, const char *dname, struct inode *inode)
+{
+ struct audit_parent *parent;
+
+ parent = container_of(i_watch, struct audit_parent, wdata);
+
+ if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
+ audit_update_watch(parent, dname, inode->i_sb->s_dev,
+ inode->i_ino, 0);
+ else if (mask & (IN_DELETE|IN_MOVED_FROM))
+ audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
+ /* inotify automatically removes the watch and sends IN_IGNORED */
+ else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
+ audit_remove_parent_watches(parent);
+ /* inotify does not remove the watch, so remove it manually */
+ else if(mask & IN_MOVE_SELF) {
+ audit_remove_parent_watches(parent);
+ inotify_remove_watch_locked(audit_ih, i_watch);
+ } else if (mask & IN_IGNORED)
+ put_inotify_watch(i_watch);
+}
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