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![Yaowei Bai](/assets/img/avatar_default.png)
This patch makes audit_tree_match return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Signed-off-by: Yaowei Bai <bywxiaobai@163.com> [PM: tweaked the subject line] Signed-off-by: Paul Moore <pmoore@redhat.com>
990 lines
23 KiB
C
990 lines
23 KiB
C
#include "audit.h"
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#include <linux/fsnotify_backend.h>
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#include <linux/namei.h>
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#include <linux/mount.h>
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#include <linux/kthread.h>
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#include <linux/slab.h>
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struct audit_tree;
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struct audit_chunk;
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struct audit_tree {
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atomic_t count;
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int goner;
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struct audit_chunk *root;
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struct list_head chunks;
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struct list_head rules;
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struct list_head list;
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struct list_head same_root;
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struct rcu_head head;
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char pathname[];
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};
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struct audit_chunk {
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struct list_head hash;
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struct fsnotify_mark mark;
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struct list_head trees; /* with root here */
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int dead;
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int count;
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atomic_long_t refs;
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struct rcu_head head;
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struct node {
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struct list_head list;
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struct audit_tree *owner;
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unsigned index; /* index; upper bit indicates 'will prune' */
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} owners[];
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};
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static LIST_HEAD(tree_list);
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static LIST_HEAD(prune_list);
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static struct task_struct *prune_thread;
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/*
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* One struct chunk is attached to each inode of interest.
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* We replace struct chunk on tagging/untagging.
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* Rules have pointer to struct audit_tree.
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* Rules have struct list_head rlist forming a list of rules over
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* the same tree.
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* References to struct chunk are collected at audit_inode{,_child}()
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* time and used in AUDIT_TREE rule matching.
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* These references are dropped at the same time we are calling
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* audit_free_names(), etc.
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*
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* Cyclic lists galore:
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* tree.chunks anchors chunk.owners[].list hash_lock
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* tree.rules anchors rule.rlist audit_filter_mutex
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* chunk.trees anchors tree.same_root hash_lock
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* chunk.hash is a hash with middle bits of watch.inode as
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* a hash function. RCU, hash_lock
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*
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* tree is refcounted; one reference for "some rules on rules_list refer to
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* it", one for each chunk with pointer to it.
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*
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* chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount
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* of watch contributes 1 to .refs).
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*
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* node.index allows to get from node.list to containing chunk.
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* MSB of that sucker is stolen to mark taggings that we might have to
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* revert - several operations have very unpleasant cleanup logics and
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* that makes a difference. Some.
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*/
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static struct fsnotify_group *audit_tree_group;
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static struct audit_tree *alloc_tree(const char *s)
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{
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struct audit_tree *tree;
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tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL);
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if (tree) {
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atomic_set(&tree->count, 1);
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tree->goner = 0;
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INIT_LIST_HEAD(&tree->chunks);
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INIT_LIST_HEAD(&tree->rules);
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INIT_LIST_HEAD(&tree->list);
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INIT_LIST_HEAD(&tree->same_root);
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tree->root = NULL;
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strcpy(tree->pathname, s);
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}
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return tree;
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}
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static inline void get_tree(struct audit_tree *tree)
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{
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atomic_inc(&tree->count);
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}
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static inline void put_tree(struct audit_tree *tree)
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{
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if (atomic_dec_and_test(&tree->count))
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kfree_rcu(tree, head);
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}
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/* to avoid bringing the entire thing in audit.h */
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const char *audit_tree_path(struct audit_tree *tree)
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{
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return tree->pathname;
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}
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static void free_chunk(struct audit_chunk *chunk)
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{
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int i;
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for (i = 0; i < chunk->count; i++) {
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if (chunk->owners[i].owner)
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put_tree(chunk->owners[i].owner);
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}
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kfree(chunk);
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}
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void audit_put_chunk(struct audit_chunk *chunk)
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{
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if (atomic_long_dec_and_test(&chunk->refs))
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free_chunk(chunk);
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}
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static void __put_chunk(struct rcu_head *rcu)
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{
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struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head);
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audit_put_chunk(chunk);
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}
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static void audit_tree_destroy_watch(struct fsnotify_mark *entry)
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{
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struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
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call_rcu(&chunk->head, __put_chunk);
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}
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static struct audit_chunk *alloc_chunk(int count)
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{
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struct audit_chunk *chunk;
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size_t size;
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int i;
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size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
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chunk = kzalloc(size, GFP_KERNEL);
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if (!chunk)
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return NULL;
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INIT_LIST_HEAD(&chunk->hash);
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INIT_LIST_HEAD(&chunk->trees);
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chunk->count = count;
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atomic_long_set(&chunk->refs, 1);
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for (i = 0; i < count; i++) {
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INIT_LIST_HEAD(&chunk->owners[i].list);
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chunk->owners[i].index = i;
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}
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fsnotify_init_mark(&chunk->mark, audit_tree_destroy_watch);
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chunk->mark.mask = FS_IN_IGNORED;
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return chunk;
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}
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enum {HASH_SIZE = 128};
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static struct list_head chunk_hash_heads[HASH_SIZE];
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static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock);
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static inline struct list_head *chunk_hash(const struct inode *inode)
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{
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unsigned long n = (unsigned long)inode / L1_CACHE_BYTES;
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return chunk_hash_heads + n % HASH_SIZE;
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}
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/* hash_lock & entry->lock is held by caller */
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static void insert_hash(struct audit_chunk *chunk)
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{
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struct fsnotify_mark *entry = &chunk->mark;
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struct list_head *list;
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if (!entry->inode)
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return;
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list = chunk_hash(entry->inode);
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list_add_rcu(&chunk->hash, list);
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}
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/* called under rcu_read_lock */
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struct audit_chunk *audit_tree_lookup(const struct inode *inode)
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{
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struct list_head *list = chunk_hash(inode);
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struct audit_chunk *p;
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list_for_each_entry_rcu(p, list, hash) {
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/* mark.inode may have gone NULL, but who cares? */
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if (p->mark.inode == inode) {
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atomic_long_inc(&p->refs);
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return p;
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}
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}
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return NULL;
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}
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bool audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree)
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{
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int n;
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for (n = 0; n < chunk->count; n++)
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if (chunk->owners[n].owner == tree)
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return true;
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return false;
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}
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/* tagging and untagging inodes with trees */
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static struct audit_chunk *find_chunk(struct node *p)
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{
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int index = p->index & ~(1U<<31);
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p -= index;
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return container_of(p, struct audit_chunk, owners[0]);
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}
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static void untag_chunk(struct node *p)
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{
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struct audit_chunk *chunk = find_chunk(p);
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struct fsnotify_mark *entry = &chunk->mark;
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struct audit_chunk *new = NULL;
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struct audit_tree *owner;
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int size = chunk->count - 1;
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int i, j;
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fsnotify_get_mark(entry);
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spin_unlock(&hash_lock);
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if (size)
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new = alloc_chunk(size);
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spin_lock(&entry->lock);
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if (chunk->dead || !entry->inode) {
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spin_unlock(&entry->lock);
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if (new)
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free_chunk(new);
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goto out;
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}
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owner = p->owner;
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if (!size) {
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chunk->dead = 1;
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spin_lock(&hash_lock);
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list_del_init(&chunk->trees);
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if (owner->root == chunk)
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owner->root = NULL;
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list_del_init(&p->list);
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list_del_rcu(&chunk->hash);
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spin_unlock(&hash_lock);
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spin_unlock(&entry->lock);
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fsnotify_destroy_mark(entry, audit_tree_group);
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goto out;
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}
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if (!new)
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goto Fallback;
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fsnotify_duplicate_mark(&new->mark, entry);
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if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.inode, NULL, 1)) {
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fsnotify_put_mark(&new->mark);
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goto Fallback;
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}
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chunk->dead = 1;
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spin_lock(&hash_lock);
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list_replace_init(&chunk->trees, &new->trees);
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if (owner->root == chunk) {
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list_del_init(&owner->same_root);
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owner->root = NULL;
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}
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for (i = j = 0; j <= size; i++, j++) {
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struct audit_tree *s;
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if (&chunk->owners[j] == p) {
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list_del_init(&p->list);
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i--;
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continue;
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}
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s = chunk->owners[j].owner;
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new->owners[i].owner = s;
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new->owners[i].index = chunk->owners[j].index - j + i;
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if (!s) /* result of earlier fallback */
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continue;
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get_tree(s);
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list_replace_init(&chunk->owners[j].list, &new->owners[i].list);
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}
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list_replace_rcu(&chunk->hash, &new->hash);
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list_for_each_entry(owner, &new->trees, same_root)
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owner->root = new;
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spin_unlock(&hash_lock);
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spin_unlock(&entry->lock);
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fsnotify_destroy_mark(entry, audit_tree_group);
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fsnotify_put_mark(&new->mark); /* drop initial reference */
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goto out;
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Fallback:
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// do the best we can
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spin_lock(&hash_lock);
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if (owner->root == chunk) {
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list_del_init(&owner->same_root);
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owner->root = NULL;
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}
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list_del_init(&p->list);
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p->owner = NULL;
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put_tree(owner);
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spin_unlock(&hash_lock);
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spin_unlock(&entry->lock);
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out:
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fsnotify_put_mark(entry);
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spin_lock(&hash_lock);
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}
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static int create_chunk(struct inode *inode, struct audit_tree *tree)
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{
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struct fsnotify_mark *entry;
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struct audit_chunk *chunk = alloc_chunk(1);
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if (!chunk)
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return -ENOMEM;
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entry = &chunk->mark;
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if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) {
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fsnotify_put_mark(entry);
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return -ENOSPC;
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}
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spin_lock(&entry->lock);
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spin_lock(&hash_lock);
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if (tree->goner) {
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spin_unlock(&hash_lock);
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chunk->dead = 1;
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spin_unlock(&entry->lock);
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fsnotify_destroy_mark(entry, audit_tree_group);
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fsnotify_put_mark(entry);
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return 0;
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}
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chunk->owners[0].index = (1U << 31);
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chunk->owners[0].owner = tree;
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get_tree(tree);
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list_add(&chunk->owners[0].list, &tree->chunks);
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if (!tree->root) {
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tree->root = chunk;
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list_add(&tree->same_root, &chunk->trees);
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}
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insert_hash(chunk);
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spin_unlock(&hash_lock);
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spin_unlock(&entry->lock);
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fsnotify_put_mark(entry); /* drop initial reference */
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return 0;
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}
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/* the first tagged inode becomes root of tree */
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static int tag_chunk(struct inode *inode, struct audit_tree *tree)
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{
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struct fsnotify_mark *old_entry, *chunk_entry;
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struct audit_tree *owner;
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struct audit_chunk *chunk, *old;
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struct node *p;
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int n;
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old_entry = fsnotify_find_inode_mark(audit_tree_group, inode);
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if (!old_entry)
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return create_chunk(inode, tree);
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old = container_of(old_entry, struct audit_chunk, mark);
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/* are we already there? */
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spin_lock(&hash_lock);
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for (n = 0; n < old->count; n++) {
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if (old->owners[n].owner == tree) {
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spin_unlock(&hash_lock);
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fsnotify_put_mark(old_entry);
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return 0;
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}
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}
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spin_unlock(&hash_lock);
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chunk = alloc_chunk(old->count + 1);
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if (!chunk) {
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fsnotify_put_mark(old_entry);
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return -ENOMEM;
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}
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chunk_entry = &chunk->mark;
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spin_lock(&old_entry->lock);
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if (!old_entry->inode) {
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/* old_entry is being shot, lets just lie */
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spin_unlock(&old_entry->lock);
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fsnotify_put_mark(old_entry);
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free_chunk(chunk);
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return -ENOENT;
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}
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fsnotify_duplicate_mark(chunk_entry, old_entry);
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if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->inode, NULL, 1)) {
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spin_unlock(&old_entry->lock);
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fsnotify_put_mark(chunk_entry);
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fsnotify_put_mark(old_entry);
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return -ENOSPC;
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}
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/* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */
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spin_lock(&chunk_entry->lock);
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spin_lock(&hash_lock);
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/* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */
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if (tree->goner) {
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spin_unlock(&hash_lock);
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chunk->dead = 1;
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spin_unlock(&chunk_entry->lock);
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spin_unlock(&old_entry->lock);
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fsnotify_destroy_mark(chunk_entry, audit_tree_group);
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fsnotify_put_mark(chunk_entry);
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fsnotify_put_mark(old_entry);
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return 0;
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}
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list_replace_init(&old->trees, &chunk->trees);
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for (n = 0, p = chunk->owners; n < old->count; n++, p++) {
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struct audit_tree *s = old->owners[n].owner;
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p->owner = s;
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p->index = old->owners[n].index;
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if (!s) /* result of fallback in untag */
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continue;
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get_tree(s);
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list_replace_init(&old->owners[n].list, &p->list);
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}
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p->index = (chunk->count - 1) | (1U<<31);
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p->owner = tree;
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get_tree(tree);
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list_add(&p->list, &tree->chunks);
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list_replace_rcu(&old->hash, &chunk->hash);
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list_for_each_entry(owner, &chunk->trees, same_root)
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owner->root = chunk;
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old->dead = 1;
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if (!tree->root) {
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tree->root = chunk;
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list_add(&tree->same_root, &chunk->trees);
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}
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spin_unlock(&hash_lock);
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spin_unlock(&chunk_entry->lock);
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spin_unlock(&old_entry->lock);
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fsnotify_destroy_mark(old_entry, audit_tree_group);
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fsnotify_put_mark(chunk_entry); /* drop initial reference */
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fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */
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return 0;
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}
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static void audit_tree_log_remove_rule(struct audit_krule *rule)
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{
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struct audit_buffer *ab;
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ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
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if (unlikely(!ab))
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return;
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audit_log_format(ab, "op=");
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audit_log_string(ab, "remove_rule");
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audit_log_format(ab, " dir=");
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audit_log_untrustedstring(ab, rule->tree->pathname);
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audit_log_key(ab, rule->filterkey);
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audit_log_format(ab, " list=%d res=1", rule->listnr);
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audit_log_end(ab);
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}
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static void kill_rules(struct audit_tree *tree)
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{
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struct audit_krule *rule, *next;
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struct audit_entry *entry;
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list_for_each_entry_safe(rule, next, &tree->rules, rlist) {
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entry = container_of(rule, struct audit_entry, rule);
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list_del_init(&rule->rlist);
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if (rule->tree) {
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/* not a half-baked one */
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audit_tree_log_remove_rule(rule);
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if (entry->rule.exe)
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audit_remove_mark(entry->rule.exe);
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rule->tree = NULL;
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list_del_rcu(&entry->list);
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list_del(&entry->rule.list);
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call_rcu(&entry->rcu, audit_free_rule_rcu);
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}
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}
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}
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/*
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* finish killing struct audit_tree
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*/
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static void prune_one(struct audit_tree *victim)
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{
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spin_lock(&hash_lock);
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while (!list_empty(&victim->chunks)) {
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struct node *p;
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p = list_entry(victim->chunks.next, struct node, list);
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untag_chunk(p);
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}
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spin_unlock(&hash_lock);
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put_tree(victim);
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}
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/* trim the uncommitted chunks from tree */
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static void trim_marked(struct audit_tree *tree)
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{
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struct list_head *p, *q;
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spin_lock(&hash_lock);
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if (tree->goner) {
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spin_unlock(&hash_lock);
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return;
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}
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/* reorder */
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for (p = tree->chunks.next; p != &tree->chunks; p = q) {
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struct node *node = list_entry(p, struct node, list);
|
|
q = p->next;
|
|
if (node->index & (1U<<31)) {
|
|
list_del_init(p);
|
|
list_add(p, &tree->chunks);
|
|
}
|
|
}
|
|
|
|
while (!list_empty(&tree->chunks)) {
|
|
struct node *node;
|
|
|
|
node = list_entry(tree->chunks.next, struct node, list);
|
|
|
|
/* have we run out of marked? */
|
|
if (!(node->index & (1U<<31)))
|
|
break;
|
|
|
|
untag_chunk(node);
|
|
}
|
|
if (!tree->root && !tree->goner) {
|
|
tree->goner = 1;
|
|
spin_unlock(&hash_lock);
|
|
mutex_lock(&audit_filter_mutex);
|
|
kill_rules(tree);
|
|
list_del_init(&tree->list);
|
|
mutex_unlock(&audit_filter_mutex);
|
|
prune_one(tree);
|
|
} else {
|
|
spin_unlock(&hash_lock);
|
|
}
|
|
}
|
|
|
|
static void audit_schedule_prune(void);
|
|
|
|
/* called with audit_filter_mutex */
|
|
int audit_remove_tree_rule(struct audit_krule *rule)
|
|
{
|
|
struct audit_tree *tree;
|
|
tree = rule->tree;
|
|
if (tree) {
|
|
spin_lock(&hash_lock);
|
|
list_del_init(&rule->rlist);
|
|
if (list_empty(&tree->rules) && !tree->goner) {
|
|
tree->root = NULL;
|
|
list_del_init(&tree->same_root);
|
|
tree->goner = 1;
|
|
list_move(&tree->list, &prune_list);
|
|
rule->tree = NULL;
|
|
spin_unlock(&hash_lock);
|
|
audit_schedule_prune();
|
|
return 1;
|
|
}
|
|
rule->tree = NULL;
|
|
spin_unlock(&hash_lock);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int compare_root(struct vfsmount *mnt, void *arg)
|
|
{
|
|
return d_backing_inode(mnt->mnt_root) == arg;
|
|
}
|
|
|
|
void audit_trim_trees(void)
|
|
{
|
|
struct list_head cursor;
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
list_add(&cursor, &tree_list);
|
|
while (cursor.next != &tree_list) {
|
|
struct audit_tree *tree;
|
|
struct path path;
|
|
struct vfsmount *root_mnt;
|
|
struct node *node;
|
|
int err;
|
|
|
|
tree = container_of(cursor.next, struct audit_tree, list);
|
|
get_tree(tree);
|
|
list_del(&cursor);
|
|
list_add(&cursor, &tree->list);
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
err = kern_path(tree->pathname, 0, &path);
|
|
if (err)
|
|
goto skip_it;
|
|
|
|
root_mnt = collect_mounts(&path);
|
|
path_put(&path);
|
|
if (IS_ERR(root_mnt))
|
|
goto skip_it;
|
|
|
|
spin_lock(&hash_lock);
|
|
list_for_each_entry(node, &tree->chunks, list) {
|
|
struct audit_chunk *chunk = find_chunk(node);
|
|
/* this could be NULL if the watch is dying else where... */
|
|
struct inode *inode = chunk->mark.inode;
|
|
node->index |= 1U<<31;
|
|
if (iterate_mounts(compare_root, inode, root_mnt))
|
|
node->index &= ~(1U<<31);
|
|
}
|
|
spin_unlock(&hash_lock);
|
|
trim_marked(tree);
|
|
drop_collected_mounts(root_mnt);
|
|
skip_it:
|
|
put_tree(tree);
|
|
mutex_lock(&audit_filter_mutex);
|
|
}
|
|
list_del(&cursor);
|
|
mutex_unlock(&audit_filter_mutex);
|
|
}
|
|
|
|
int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
|
|
{
|
|
|
|
if (pathname[0] != '/' ||
|
|
rule->listnr != AUDIT_FILTER_EXIT ||
|
|
op != Audit_equal ||
|
|
rule->inode_f || rule->watch || rule->tree)
|
|
return -EINVAL;
|
|
rule->tree = alloc_tree(pathname);
|
|
if (!rule->tree)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
void audit_put_tree(struct audit_tree *tree)
|
|
{
|
|
put_tree(tree);
|
|
}
|
|
|
|
static int tag_mount(struct vfsmount *mnt, void *arg)
|
|
{
|
|
return tag_chunk(d_backing_inode(mnt->mnt_root), arg);
|
|
}
|
|
|
|
/*
|
|
* That gets run when evict_chunk() ends up needing to kill audit_tree.
|
|
* Runs from a separate thread.
|
|
*/
|
|
static int prune_tree_thread(void *unused)
|
|
{
|
|
for (;;) {
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
if (list_empty(&prune_list))
|
|
schedule();
|
|
__set_current_state(TASK_RUNNING);
|
|
|
|
mutex_lock(&audit_cmd_mutex);
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
while (!list_empty(&prune_list)) {
|
|
struct audit_tree *victim;
|
|
|
|
victim = list_entry(prune_list.next,
|
|
struct audit_tree, list);
|
|
list_del_init(&victim->list);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
prune_one(victim);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
}
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
mutex_unlock(&audit_cmd_mutex);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int audit_launch_prune(void)
|
|
{
|
|
if (prune_thread)
|
|
return 0;
|
|
prune_thread = kthread_create(prune_tree_thread, NULL,
|
|
"audit_prune_tree");
|
|
if (IS_ERR(prune_thread)) {
|
|
pr_err("cannot start thread audit_prune_tree");
|
|
prune_thread = NULL;
|
|
return -ENOMEM;
|
|
} else {
|
|
wake_up_process(prune_thread);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* called with audit_filter_mutex */
|
|
int audit_add_tree_rule(struct audit_krule *rule)
|
|
{
|
|
struct audit_tree *seed = rule->tree, *tree;
|
|
struct path path;
|
|
struct vfsmount *mnt;
|
|
int err;
|
|
|
|
rule->tree = NULL;
|
|
list_for_each_entry(tree, &tree_list, list) {
|
|
if (!strcmp(seed->pathname, tree->pathname)) {
|
|
put_tree(seed);
|
|
rule->tree = tree;
|
|
list_add(&rule->rlist, &tree->rules);
|
|
return 0;
|
|
}
|
|
}
|
|
tree = seed;
|
|
list_add(&tree->list, &tree_list);
|
|
list_add(&rule->rlist, &tree->rules);
|
|
/* do not set rule->tree yet */
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
if (unlikely(!prune_thread)) {
|
|
err = audit_launch_prune();
|
|
if (err)
|
|
goto Err;
|
|
}
|
|
|
|
err = kern_path(tree->pathname, 0, &path);
|
|
if (err)
|
|
goto Err;
|
|
mnt = collect_mounts(&path);
|
|
path_put(&path);
|
|
if (IS_ERR(mnt)) {
|
|
err = PTR_ERR(mnt);
|
|
goto Err;
|
|
}
|
|
|
|
get_tree(tree);
|
|
err = iterate_mounts(tag_mount, tree, mnt);
|
|
drop_collected_mounts(mnt);
|
|
|
|
if (!err) {
|
|
struct node *node;
|
|
spin_lock(&hash_lock);
|
|
list_for_each_entry(node, &tree->chunks, list)
|
|
node->index &= ~(1U<<31);
|
|
spin_unlock(&hash_lock);
|
|
} else {
|
|
trim_marked(tree);
|
|
goto Err;
|
|
}
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
if (list_empty(&rule->rlist)) {
|
|
put_tree(tree);
|
|
return -ENOENT;
|
|
}
|
|
rule->tree = tree;
|
|
put_tree(tree);
|
|
|
|
return 0;
|
|
Err:
|
|
mutex_lock(&audit_filter_mutex);
|
|
list_del_init(&tree->list);
|
|
list_del_init(&tree->rules);
|
|
put_tree(tree);
|
|
return err;
|
|
}
|
|
|
|
int audit_tag_tree(char *old, char *new)
|
|
{
|
|
struct list_head cursor, barrier;
|
|
int failed = 0;
|
|
struct path path1, path2;
|
|
struct vfsmount *tagged;
|
|
int err;
|
|
|
|
err = kern_path(new, 0, &path2);
|
|
if (err)
|
|
return err;
|
|
tagged = collect_mounts(&path2);
|
|
path_put(&path2);
|
|
if (IS_ERR(tagged))
|
|
return PTR_ERR(tagged);
|
|
|
|
err = kern_path(old, 0, &path1);
|
|
if (err) {
|
|
drop_collected_mounts(tagged);
|
|
return err;
|
|
}
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
list_add(&barrier, &tree_list);
|
|
list_add(&cursor, &barrier);
|
|
|
|
while (cursor.next != &tree_list) {
|
|
struct audit_tree *tree;
|
|
int good_one = 0;
|
|
|
|
tree = container_of(cursor.next, struct audit_tree, list);
|
|
get_tree(tree);
|
|
list_del(&cursor);
|
|
list_add(&cursor, &tree->list);
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
err = kern_path(tree->pathname, 0, &path2);
|
|
if (!err) {
|
|
good_one = path_is_under(&path1, &path2);
|
|
path_put(&path2);
|
|
}
|
|
|
|
if (!good_one) {
|
|
put_tree(tree);
|
|
mutex_lock(&audit_filter_mutex);
|
|
continue;
|
|
}
|
|
|
|
failed = iterate_mounts(tag_mount, tree, tagged);
|
|
if (failed) {
|
|
put_tree(tree);
|
|
mutex_lock(&audit_filter_mutex);
|
|
break;
|
|
}
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
spin_lock(&hash_lock);
|
|
if (!tree->goner) {
|
|
list_del(&tree->list);
|
|
list_add(&tree->list, &tree_list);
|
|
}
|
|
spin_unlock(&hash_lock);
|
|
put_tree(tree);
|
|
}
|
|
|
|
while (barrier.prev != &tree_list) {
|
|
struct audit_tree *tree;
|
|
|
|
tree = container_of(barrier.prev, struct audit_tree, list);
|
|
get_tree(tree);
|
|
list_del(&tree->list);
|
|
list_add(&tree->list, &barrier);
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
if (!failed) {
|
|
struct node *node;
|
|
spin_lock(&hash_lock);
|
|
list_for_each_entry(node, &tree->chunks, list)
|
|
node->index &= ~(1U<<31);
|
|
spin_unlock(&hash_lock);
|
|
} else {
|
|
trim_marked(tree);
|
|
}
|
|
|
|
put_tree(tree);
|
|
mutex_lock(&audit_filter_mutex);
|
|
}
|
|
list_del(&barrier);
|
|
list_del(&cursor);
|
|
mutex_unlock(&audit_filter_mutex);
|
|
path_put(&path1);
|
|
drop_collected_mounts(tagged);
|
|
return failed;
|
|
}
|
|
|
|
|
|
static void audit_schedule_prune(void)
|
|
{
|
|
wake_up_process(prune_thread);
|
|
}
|
|
|
|
/*
|
|
* ... and that one is done if evict_chunk() decides to delay until the end
|
|
* of syscall. Runs synchronously.
|
|
*/
|
|
void audit_kill_trees(struct list_head *list)
|
|
{
|
|
mutex_lock(&audit_cmd_mutex);
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
while (!list_empty(list)) {
|
|
struct audit_tree *victim;
|
|
|
|
victim = list_entry(list->next, struct audit_tree, list);
|
|
kill_rules(victim);
|
|
list_del_init(&victim->list);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
prune_one(victim);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
}
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
mutex_unlock(&audit_cmd_mutex);
|
|
}
|
|
|
|
/*
|
|
* Here comes the stuff asynchronous to auditctl operations
|
|
*/
|
|
|
|
static void evict_chunk(struct audit_chunk *chunk)
|
|
{
|
|
struct audit_tree *owner;
|
|
struct list_head *postponed = audit_killed_trees();
|
|
int need_prune = 0;
|
|
int n;
|
|
|
|
if (chunk->dead)
|
|
return;
|
|
|
|
chunk->dead = 1;
|
|
mutex_lock(&audit_filter_mutex);
|
|
spin_lock(&hash_lock);
|
|
while (!list_empty(&chunk->trees)) {
|
|
owner = list_entry(chunk->trees.next,
|
|
struct audit_tree, same_root);
|
|
owner->goner = 1;
|
|
owner->root = NULL;
|
|
list_del_init(&owner->same_root);
|
|
spin_unlock(&hash_lock);
|
|
if (!postponed) {
|
|
kill_rules(owner);
|
|
list_move(&owner->list, &prune_list);
|
|
need_prune = 1;
|
|
} else {
|
|
list_move(&owner->list, postponed);
|
|
}
|
|
spin_lock(&hash_lock);
|
|
}
|
|
list_del_rcu(&chunk->hash);
|
|
for (n = 0; n < chunk->count; n++)
|
|
list_del_init(&chunk->owners[n].list);
|
|
spin_unlock(&hash_lock);
|
|
mutex_unlock(&audit_filter_mutex);
|
|
if (need_prune)
|
|
audit_schedule_prune();
|
|
}
|
|
|
|
static int audit_tree_handle_event(struct fsnotify_group *group,
|
|
struct inode *to_tell,
|
|
struct fsnotify_mark *inode_mark,
|
|
struct fsnotify_mark *vfsmount_mark,
|
|
u32 mask, void *data, int data_type,
|
|
const unsigned char *file_name, u32 cookie)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group)
|
|
{
|
|
struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
|
|
|
|
evict_chunk(chunk);
|
|
|
|
/*
|
|
* We are guaranteed to have at least one reference to the mark from
|
|
* either the inode or the caller of fsnotify_destroy_mark().
|
|
*/
|
|
BUG_ON(atomic_read(&entry->refcnt) < 1);
|
|
}
|
|
|
|
static const struct fsnotify_ops audit_tree_ops = {
|
|
.handle_event = audit_tree_handle_event,
|
|
.freeing_mark = audit_tree_freeing_mark,
|
|
};
|
|
|
|
static int __init audit_tree_init(void)
|
|
{
|
|
int i;
|
|
|
|
audit_tree_group = fsnotify_alloc_group(&audit_tree_ops);
|
|
if (IS_ERR(audit_tree_group))
|
|
audit_panic("cannot initialize fsnotify group for rectree watches");
|
|
|
|
for (i = 0; i < HASH_SIZE; i++)
|
|
INIT_LIST_HEAD(&chunk_hash_heads[i]);
|
|
|
|
return 0;
|
|
}
|
|
__initcall(audit_tree_init);
|