From 2529a0df0f64dab1f60ae08e038b89c53a6b4c02 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 28 Oct 2010 17:21:57 -0400 Subject: fsnotify: implement a default maximum queue depth Currently fanotify has no maximum queue depth. Since fanotify is CAP_SYS_ADMIN only this does not pose a normal user DoS issue, but it certianly is possible that an fanotify listener which can't keep up could OOM the box. This patch implements a default 16k depth. This is the same default depth used by inotify, but given fanotify's better queue merging in many situations this queue will contain many additional useful events by comparison. Signed-off-by: Eric Paris --- fs/notify/fanotify/fanotify_user.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/notify') diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index b265936e92d..04f2fe47b66 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -16,6 +16,8 @@ #include +#define FANOTIFY_DEFAULT_MAX_EVENTS 16384 + extern const struct fsnotify_ops fanotify_fsnotify_ops; static struct kmem_cache *fanotify_mark_cache __read_mostly; @@ -689,6 +691,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) goto out_put_group; } + group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS; + fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags); if (fd < 0) goto out_put_group; -- cgit v1.2.3-70-g09d2