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| author | Eric Paris <eparis@redhat.com> | 2010-10-28 17:21:58 -0400 |
|---|---|---|
| committer | Eric Paris <eparis@redhat.com> | 2010-10-28 17:22:15 -0400 |
| commit | 4afeff8505cb8a38e36c1ef2bd3447c4b8f87367 (patch) | |
| tree | 50a80d8773698813e4e9d9f9112079c09d493c48 /fs/notify | |
| parent | ac7e22dcfafd04c842a02057afd6541c1d613ef9 (diff) | |
| download | linux-4afeff8505cb8a38e36c1ef2bd3447c4b8f87367.tar.gz linux-4afeff8505cb8a38e36c1ef2bd3447c4b8f87367.tar.bz2 linux-4afeff8505cb8a38e36c1ef2bd3447c4b8f87367.zip | |
fanotify: limit number of listeners per user
fanotify currently has no limit on the number of listeners a given user can
have open. This patch limits the total number of listeners per user to
128. This is the same as the inotify default limit.
Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 11 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 11 |
2 files changed, 21 insertions, 1 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 85366c78cc37..60c11c306fd9 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -200,10 +200,19 @@ static bool fanotify_should_send_event(struct fsnotify_group *group, return false; } +static void fanotify_free_group_priv(struct fsnotify_group *group) +{ + struct user_struct *user; + + user = group->fanotify_data.user; + atomic_dec(&user->fanotify_listeners); + free_uid(user); +} + const struct fsnotify_ops fanotify_fsnotify_ops = { .handle_event = fanotify_handle_event, .should_send_event = fanotify_should_send_event, - .free_group_priv = NULL, + .free_group_priv = fanotify_free_group_priv, .free_event_priv = NULL, .freeing_mark = NULL, }; diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index f9216102b426..a7d9369482d5 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -18,6 +18,7 @@ #define FANOTIFY_DEFAULT_MAX_EVENTS 16384 #define FANOTIFY_DEFAULT_MAX_MARKS 8192 +#define FANOTIFY_DEFAULT_MAX_LISTENERS 128 extern const struct fsnotify_ops fanotify_fsnotify_ops; @@ -656,6 +657,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) { struct fsnotify_group *group; int f_flags, fd; + struct user_struct *user; pr_debug("%s: flags=%d event_f_flags=%d\n", __func__, flags, event_f_flags); @@ -666,6 +668,12 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) if (flags & ~FAN_ALL_INIT_FLAGS) return -EINVAL; + user = get_current_user(); + if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) { + free_uid(user); + return -EMFILE; + } + f_flags = O_RDWR | FMODE_NONOTIFY; if (flags & FAN_CLOEXEC) f_flags |= O_CLOEXEC; @@ -677,6 +685,9 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) if (IS_ERR(group)) return PTR_ERR(group); + group->fanotify_data.user = user; + atomic_inc(&user->fanotify_listeners); + group->fanotify_data.f_flags = event_f_flags; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS mutex_init(&group->fanotify_data.access_mutex); |