/* audit_watch.c -- watching inodes * * Copyright 2003-2009 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/slab.h>#include <linux/inotify.h>#include <linux/security.h>#include "audit.h" /* * 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_watch { atomic_t count; /* reference count */ dev_t dev; /* associated superblock device */ char *path; /* insertion path */ unsigned long ino; /* associated inode number */ struct audit_parent *parent; /* associated parent */ struct list_head wlist; /* entry in parent->watches list */ struct list_head rules; /* associated rules */}; 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 */}; /* Inotify handle. */struct inotify_handle *audit_ih; /* * 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 /* Inotify events we care about. */#define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF static 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);} void audit_get_watch(struct audit_watch *watch){ atomic_inc(&watch->count);} 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); }} 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 */} char *audit_watch_path(struct audit_watch *watch){ return watch->path;} struct list_head *audit_watch_rules(struct audit_watch *watch){ return &watch->rules;} unsigned long audit_watch_inode(struct audit_watch *watch){ return watch->ino;} dev_t audit_watch_dev(struct audit_watch *watch){ return watch->dev;} /* 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;} /* Translate a watch string to kernel respresentation. */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;} /* 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;} static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op){ if (audit_enabled) { struct audit_buffer *ab; ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE); audit_log_format(ab, "auid=%u ses=%u op=", audit_get_loginuid(current), audit_get_sessionid(current)); audit_log_string(ab, op); audit_log_format(ab, " path="); audit_log_untrustedstring(ab, w->path); audit_log_key(ab, r->filterkey); audit_log_format(ab, " list=%d res=1", r->listnr); audit_log_end(ab); }} /* 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); 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)) { list_del(&oentry->rule.list); 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]); list_replace(&oentry->rule.list, &nentry->rule.list); } audit_watch_log_rule_change(r, owatch, "updated rules"); call_rcu(&oentry->rcu, audit_free_rule_rcu); } 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); audit_watch_log_rule_change(r, w, "remove rule"); list_del(&r->rlist); list_del(&r->list); 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. */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); }} /* 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. */int audit_add_watch(struct audit_krule *krule){ struct audit_watch *watch = krule->watch; struct inotify_watch *i_watch; struct audit_parent *parent; struct nameidata *ndp = NULL, *ndw = NULL; int ret = 0; mutex_unlock(&audit_filter_mutex); /* Avoid calling path_lookup under audit_filter_mutex. */ ret = audit_get_nd(watch->path, &ndp, &ndw); if (ret) { /* caller expects mutex locked */ mutex_lock(&audit_filter_mutex); goto error; } /* 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. */ 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); ret = PTR_ERR(parent); goto error; } } 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); error: audit_put_nd(ndp, ndw); /* NULL args OK */ return ret; } void audit_remove_watch_rule(struct audit_krule *krule, struct list_head *list){ struct audit_watch *watch = krule->watch; struct audit_parent *parent = watch->parent; list_del(&krule->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 takeLines 1–500 of 544. Load more
/* audit_watch.c -- watching inodes * * Copyright 2003-2009 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/slab.h> #include <linux/inotify.h> #include <linux/security.h> #include "audit.h" /* * 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_watch { atomic_t count; /* reference count */ dev_t dev; /* associated superblock device */ char *path; /* insertion path */ unsigned long ino; /* associated inode number */ struct audit_parent *parent; /* associated parent */ struct list_head wlist; /* entry in parent->watches list */ struct list_head rules; /* associated rules */ }; 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 */ }; /* Inotify handle. */ struct inotify_handle *audit_ih; /* * 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 /* Inotify events we care about. */ #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF static 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); } void audit_get_watch(struct audit_watch *watch) { atomic_inc(&watch->count); } 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); } } 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 */ } char *audit_watch_path(struct audit_watch *watch) { return watch->path; } struct list_head *audit_watch_rules(struct audit_watch *watch) { return &watch->rules; } unsigned long audit_watch_inode(struct audit_watch *watch) { return watch->ino; } dev_t audit_watch_dev(struct audit_watch *watch) { return watch->dev; } /* 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; } /* Translate a watch string to kernel respresentation. */ 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; } /* 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; } static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op) { if (audit_enabled) { struct audit_buffer *ab; ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE); audit_log_format(ab, "auid=%u ses=%u op=", audit_get_loginuid(current), audit_get_sessionid(current)); audit_log_string(ab, op); audit_log_format(ab, " path="); audit_log_untrustedstring(ab, w->path); audit_log_key(ab, r->filterkey); audit_log_format(ab, " list=%d res=1", r->listnr); audit_log_end(ab); } } /* 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); 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)) { list_del(&oentry->rule.list); 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]); list_replace(&oentry->rule.list, &nentry->rule.list); } audit_watch_log_rule_change(r, owatch, "updated rules"); call_rcu(&oentry->rcu, audit_free_rule_rcu); } 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); audit_watch_log_rule_change(r, w, "remove rule"); list_del(&r->rlist); list_del(&r->list); 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. */ 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); } } /* 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. */ int audit_add_watch(struct audit_krule *krule) { struct audit_watch *watch = krule->watch; struct inotify_watch *i_watch; struct audit_parent *parent; struct nameidata *ndp = NULL, *ndw = NULL; int ret = 0; mutex_unlock(&audit_filter_mutex); /* Avoid calling path_lookup under audit_filter_mutex. */ ret = audit_get_nd(watch->path, &ndp, &ndw); if (ret) { /* caller expects mutex locked */ mutex_lock(&audit_filter_mutex); goto error; } /* 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. */ 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); ret = PTR_ERR(parent); goto error; } } 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); error: audit_put_nd(ndp, ndw); /* NULL args OK */ return ret; } void audit_remove_watch_rule(struct audit_krule *krule, struct list_head *list) { struct audit_watch *watch = krule->watch; struct audit_parent *parent = watch->parent; list_del(&krule->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