Re: audit.60 kernel (Re: [PATCH] bug fixes + cleanups against audit.58)

On Sun, 2005-06-19 at 19:29 +0100, David Woodhouse wrote: To answer the rhetorical question... --- linux-2.6.9/kernel/auditsc.c~ 2005-06-19 20:28:08.000000000 +0100 +++ linux-2.6.9/kernel/auditsc.c 2005-06-19 23:13:33.000000000 +0100 @@ -1232,6 +1232,8 @@ void audit_signal_info(int sig, struct t } #ifdef CONFIG_AUDITFILESYSTEM +extern spinlock_t auditfs_lock; + /* This has to be here instead of in auditfs.c, because it needs to see the audit context */ void auditfs_attach_wdata(struct inode *inode, struct hlist_head *watches, @@ -1252,7 +1254,11 @@ void auditfs_attach_wdata(struct inode * INIT_HLIST_HEAD(&ax->watches); + spin_lock(&auditfs_lock); hlist_for_each_entry(watch, pos, watches, w_watched) { + restart: + audit_watch_get(watch); + spin_unlock(&auditfs_lock); winfo = kmalloc(sizeof(struct audit_watch_info), GFP_KERNEL); if (!winfo) goto auditfs_attach_wdata_fail; @@ -1260,7 +1266,25 @@ void auditfs_attach_wdata(struct inode * continue; winfo->watch = audit_watch_get(watch); hlist_add_head(&winfo->node, &ax->watches); + spin_lock(&auditfs_lock); + if (hlist_unhashed(&watch->w_watched)) { + audit_watch_put(watch); + /* Someone took it off the list while we didn't have it locked. + Go through the list of watches again until we find one which + we haven't already dealt with... */ + hlist_for_each_entry(watch, pos, watches, w_watched) { + hlist_for_each_entry(winfo, tmp, &ax->watches, node) { + if (winfo->watch == watch) + continue; + } + /* This watch wasn't found on ax's list, so + pick up where we left off. */ + goto restart; + } + } + audit_watch_put(watch); } + spin_unlock(&auditfs_lock); if (context->in_syscall && !context->auditable && AUDIT_DISABLED != audit_filter_syscall(current, context, --- linux-2.6.9/kernel/auditfs.c~ 2005-06-19 18:53:58.000000000 +0100 +++ linux-2.6.9/kernel/auditfs.c 2005-06-19 22:27:41.000000000 +0100 @@ -52,7 +52,7 @@ extern int audit_enabled; static kmem_cache_t *audit_watch_cache; static HLIST_HEAD(master_watchlist); -static spinlock_t auditfs_lock = SPIN_LOCK_UNLOCKED; +spinlock_t auditfs_lock = SPIN_LOCK_UNLOCKED; struct audit_skb_list { struct hlist_node list; -- dwmw2