diff options
Diffstat (limited to 'kernel/audit_watch.c')
-rw-r--r-- | kernel/audit_watch.c | 274 |
1 files changed, 149 insertions, 125 deletions
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index 8df4369..f0c9b2e 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -24,18 +24,18 @@ #include <linux/kthread.h> #include <linux/mutex.h> #include <linux/fs.h> +#include <linux/fsnotify_backend.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 + * audit_parent: lifetime is from audit_init_parent() to receipt of an FS_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 @@ -51,40 +51,61 @@ struct audit_watch { 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 list_head rules; /* anchor for krule->rlist */ }; 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 */ + struct list_head watches; /* anchor for audit_watch->wlist */ + struct fsnotify_mark mark; /* fsnotify mark on the inode */ }; -/* Inotify handle. */ -struct inotify_handle *audit_ih; +/* fsnotify handle. */ +struct fsnotify_group *audit_watch_group; -/* - * 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 +/* fsnotify events we care about. */ +#define AUDIT_FS_WATCH (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\ + FS_MOVE_SELF | FS_EVENT_ON_CHILD) -/* 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 audit_parent *parent) +{ + WARN_ON(!list_empty(&parent->watches)); + kfree(parent); +} -static void audit_free_parent(struct inotify_watch *i_watch) +static void audit_watch_free_mark(struct fsnotify_mark *entry) { struct audit_parent *parent; - parent = container_of(i_watch, struct audit_parent, wdata); - WARN_ON(!list_empty(&parent->watches)); - kfree(parent); + parent = container_of(entry, struct audit_parent, mark); + audit_free_parent(parent); +} + +static void audit_get_parent(struct audit_parent *parent) +{ + if (likely(parent)) + fsnotify_get_mark(&parent->mark); +} + +static void audit_put_parent(struct audit_parent *parent) +{ + if (likely(parent)) + fsnotify_put_mark(&parent->mark); +} + +/* + * Find and return the audit_parent on the given inode. If found a reference + * is taken on this parent. + */ +static inline struct audit_parent *audit_find_parent(struct inode *inode) +{ + struct audit_parent *parent = NULL; + struct fsnotify_mark *entry; + + entry = fsnotify_find_inode_mark(audit_watch_group, inode); + if (entry) + parent = container_of(entry, struct audit_parent, mark); + + return parent; } void audit_get_watch(struct audit_watch *watch) @@ -105,7 +126,7 @@ void audit_put_watch(struct audit_watch *watch) void audit_remove_watch(struct audit_watch *watch) { list_del(&watch->wlist); - put_inotify_watch(&watch->parent->wdata); + audit_put_parent(watch->parent); watch->parent = NULL; audit_put_watch(watch); /* match initial get */ } @@ -115,42 +136,32 @@ 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) +int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev) { - return watch->ino; -} - -dev_t audit_watch_dev(struct audit_watch *watch) -{ - return watch->dev; + return (watch->ino != (unsigned long)-1) && + (watch->ino == ino) && + (watch->dev == dev); } /* Initialize a parent watch entry. */ static struct audit_parent *audit_init_parent(struct nameidata *ndp) { + struct inode *inode = ndp->path.dentry->d_inode; struct audit_parent *parent; - s32 wd; + int ret; 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); + + fsnotify_init_mark(&parent->mark, audit_watch_free_mark); + parent->mark.mask = AUDIT_FS_WATCH; + ret = fsnotify_add_mark(&parent->mark, audit_watch_group, inode, NULL, 0); + if (ret < 0) { + audit_free_parent(parent); + return ERR_PTR(ret); } return parent; @@ -179,7 +190,7 @@ int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op) { struct audit_watch *watch; - if (!audit_ih) + if (!audit_watch_group) return -EOPNOTSUPP; if (path[0] != '/' || path[len-1] == '/' || @@ -217,7 +228,7 @@ static struct audit_watch *audit_dupe_watch(struct audit_watch *old) new->dev = old->dev; new->ino = old->ino; - get_inotify_watch(&old->parent->wdata); + audit_get_parent(old->parent); new->parent = old->parent; out: @@ -251,15 +262,19 @@ static void audit_update_watch(struct audit_parent *parent, struct audit_entry *oentry, *nentry; mutex_lock(&audit_filter_mutex); + /* Run all of the watches on this parent looking for the one that + * matches the given dname */ 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) + if (invalidating && !audit_dummy_context()) audit_filter_inodes(current, current->audit_context); + /* updating ino will likely change which audit_hash_list we + * are on so we need a new watch for the new list */ nwatch = audit_dupe_watch(owatch); if (IS_ERR(nwatch)) { mutex_unlock(&audit_filter_mutex); @@ -275,12 +290,21 @@ static void audit_update_watch(struct audit_parent *parent, list_del(&oentry->rule.rlist); list_del_rcu(&oentry->list); - nentry = audit_dupe_rule(&oentry->rule, nwatch); + nentry = audit_dupe_rule(&oentry->rule); if (IS_ERR(nentry)) { list_del(&oentry->rule.list); audit_panic("error updating watch, removing"); } else { int h = audit_hash_ino((u32)ino); + + /* + * nentry->rule.watch == oentry->rule.watch so + * we must drop that reference and set it to our + * new watch. + */ + audit_put_watch(nentry->rule.watch); + audit_get_watch(nwatch); + nentry->rule.watch = nwatch; list_add(&nentry->rule.rlist, &nwatch->rules); list_add_rcu(&nentry->list, &audit_inode_hash[h]); list_replace(&oentry->rule.list, @@ -312,7 +336,6 @@ static void audit_remove_parent_watches(struct audit_parent *parent) 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); @@ -325,20 +348,8 @@ static void audit_remove_parent_watches(struct audit_parent *parent) 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); - } + fsnotify_destroy_mark(&parent->mark); } /* Get path information necessary for adding watches. */ @@ -389,7 +400,7 @@ static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw) } } -/* Associate the given rule with an existing parent inotify_watch. +/* Associate the given rule with an existing parent. * Caller must hold audit_filter_mutex. */ static void audit_add_to_parent(struct audit_krule *krule, struct audit_parent *parent) @@ -397,6 +408,8 @@ static void audit_add_to_parent(struct audit_krule *krule, struct audit_watch *w, *watch = krule->watch; int watch_found = 0; + BUG_ON(!mutex_is_locked(&audit_filter_mutex)); + list_for_each_entry(w, &parent->watches, wlist) { if (strcmp(watch->path, w->path)) continue; @@ -413,7 +426,7 @@ static void audit_add_to_parent(struct audit_krule *krule, } if (!watch_found) { - get_inotify_watch(&parent->wdata); + audit_get_parent(parent); watch->parent = parent; list_add(&watch->wlist, &parent->watches); @@ -423,13 +436,12 @@ static void audit_add_to_parent(struct audit_krule *krule, /* Find a matching watch entry, or add this one. * Caller must hold audit_filter_mutex. */ -int audit_add_watch(struct audit_krule *krule) +int audit_add_watch(struct audit_krule *krule, struct list_head **list) { struct audit_watch *watch = krule->watch; - struct inotify_watch *i_watch; struct audit_parent *parent; struct nameidata *ndp = NULL, *ndw = NULL; - int ret = 0; + int h, ret = 0; mutex_unlock(&audit_filter_mutex); @@ -441,47 +453,38 @@ int audit_add_watch(struct audit_krule *krule) goto error; } + mutex_lock(&audit_filter_mutex); + /* 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) { + /* either find an old parent or attach a new one */ + parent = audit_find_parent(ndp->path.dentry->d_inode); + if (!parent) { 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); + audit_add_to_parent(krule, parent); - /* match get in audit_init_parent or inotify_find_watch */ - put_inotify_watch(&parent->wdata); + /* match get in audit_find_parent or audit_init_parent */ + audit_put_parent(parent); + h = audit_hash_ino((u32)watch->ino); + *list = &audit_inode_hash[h]; error: audit_put_nd(ndp, ndw); /* NULL args OK */ return ret; } -void audit_remove_watch_rule(struct audit_krule *krule, struct list_head *list) +void audit_remove_watch_rule(struct audit_krule *krule) { struct audit_watch *watch = krule->watch; struct audit_parent *parent = watch->parent; @@ -492,53 +495,74 @@ void audit_remove_watch_rule(struct audit_krule *krule, struct list_head *list) 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, list); + audit_get_parent(parent); + fsnotify_destroy_mark(&parent->mark); + audit_put_parent(parent); } } } -/* Update watch data in audit rules based on inotify events. */ -static void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask, - u32 cookie, const char *dname, struct inode *inode) +static bool audit_watch_should_send_event(struct fsnotify_group *group, struct inode *inode, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *vfsmount_mark, + __u32 mask, void *data, int data_type) +{ + return true; +} + +/* Update watch data in audit rules based on fsnotify events. */ +static int audit_watch_handle_event(struct fsnotify_group *group, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *vfsmount_mark, + struct fsnotify_event *event) { + struct inode *inode; + __u32 mask = event->mask; + const char *dname = event->file_name; struct audit_parent *parent; - parent = container_of(i_watch, struct audit_parent, wdata); + parent = container_of(inode_mark, struct audit_parent, mark); - 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)) + BUG_ON(group != audit_watch_group); + + switch (event->data_type) { + case (FSNOTIFY_EVENT_PATH): + inode = event->path.dentry->d_inode; + break; + case (FSNOTIFY_EVENT_INODE): + inode = event->inode; + break; + default: + BUG(); + inode = NULL; + break; + }; + + if (mask & (FS_CREATE|FS_MOVED_TO) && inode) + audit_update_watch(parent, dname, inode->i_sb->s_dev, inode->i_ino, 0); + else if (mask & (FS_DELETE|FS_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) { + else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_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); + + return 0; } -static const struct inotify_operations audit_inotify_ops = { - .handle_event = audit_handle_ievent, - .destroy_watch = audit_free_parent, +static const struct fsnotify_ops audit_watch_fsnotify_ops = { + .should_send_event = audit_watch_should_send_event, + .handle_event = audit_watch_handle_event, + .free_group_priv = NULL, + .freeing_mark = NULL, + .free_event_priv = NULL, }; static int __init audit_watch_init(void) { - audit_ih = inotify_init(&audit_inotify_ops); - if (IS_ERR(audit_ih)) - audit_panic("cannot initialize inotify handle"); + audit_watch_group = fsnotify_alloc_group(&audit_watch_fsnotify_ops); + if (IS_ERR(audit_watch_group)) { + audit_watch_group = NULL; + audit_panic("cannot create audit fsnotify group"); + } return 0; } -subsys_initcall(audit_watch_init); +device_initcall(audit_watch_init); |