diff options
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 11 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 11 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 3 |
4 files changed, 25 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); diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 49ceed6e92b1..4366f458a86a 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -170,6 +170,7 @@ struct fsnotify_group { #endif /* CONFIG_FANOTIFY_ACCESS_PERMISSIONS */ int f_flags; unsigned int max_marks; + struct user_struct *user; } fanotify_data; #endif /* CONFIG_FANOTIFY */ }; diff --git a/include/linux/sched.h b/include/linux/sched.h index be7adb7588e5..6f420baf37ca 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -672,6 +672,9 @@ struct user_struct { atomic_t inotify_watches; /* How many inotify watches does this user have? */ atomic_t inotify_devs; /* How many inotify devs does this user have opened? */ #endif +#ifdef CONFIG_FANOTIFY + atomic_t fanotify_listeners; +#endif #ifdef CONFIG_EPOLL atomic_t epoll_watches; /* The number of file descriptors currently watched */ #endif |