#include <asm/ioctls.h>
+#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;
static struct kmem_cache *fanotify_mark_cache __read_mostly;
return client_fd;
}
-static ssize_t fill_event_metadata(struct fsnotify_group *group,
+static int fill_event_metadata(struct fsnotify_group *group,
struct fanotify_event_metadata *metadata,
struct fsnotify_event *event)
{
+ int ret = 0;
+
pr_debug("%s: group=%p metadata=%p event=%p\n", __func__,
group, metadata, event);
metadata->event_len = FAN_EVENT_METADATA_LEN;
+ metadata->metadata_len = FAN_EVENT_METADATA_LEN;
metadata->vers = FANOTIFY_METADATA_VERSION;
metadata->mask = event->mask & FAN_ALL_OUTGOING_EVENTS;
metadata->pid = pid_vnr(event->tgid);
- metadata->fd = create_fd(group, event);
+ if (unlikely(event->mask & FAN_Q_OVERFLOW))
+ metadata->fd = FAN_NOFD;
+ else {
+ metadata->fd = create_fd(group, event);
+ if (metadata->fd < 0)
+ ret = metadata->fd;
+ }
- return metadata->fd;
+ return ret;
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
mutex_lock(&group->fanotify_data.access_mutex);
- if (group->fanotify_data.bypass_perm) {
+ if (atomic_read(&group->fanotify_data.bypass_perm)) {
mutex_unlock(&group->fanotify_data.access_mutex);
kmem_cache_free(fanotify_response_event_cache, re);
event->response = FAN_ALLOW;
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
- fd = fill_event_metadata(group, &fanotify_event_metadata, event);
- if (fd < 0)
- return fd;
+ ret = fill_event_metadata(group, &fanotify_event_metadata, event);
+ if (ret < 0)
+ goto out;
+ fd = fanotify_event_metadata.fd;
ret = prepare_for_access_response(group, event, fd);
if (ret)
goto out_close_fd;
ret = -EFAULT;
- if (copy_to_user(buf, &fanotify_event_metadata, FAN_EVENT_METADATA_LEN))
+ if (copy_to_user(buf, &fanotify_event_metadata,
+ fanotify_event_metadata.event_len))
goto out_kill_access_response;
- return FAN_EVENT_METADATA_LEN;
+ return fanotify_event_metadata.event_len;
out_kill_access_response:
remove_access_response(group, event, fd);
out_close_fd:
- sys_close(fd);
+ if (fd != FAN_NOFD)
+ sys_close(fd);
+out:
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ if (event->mask & FAN_ALL_PERM_EVENTS) {
+ event->response = FAN_DENY;
+ wake_up(&group->fanotify_data.access_waitq);
+ }
+#endif
return ret;
}
ret = -EAGAIN;
if (file->f_flags & O_NONBLOCK)
break;
- ret = -EINTR;
+ ret = -ERESTARTSYS;
if (signal_pending(current))
break;
static int fanotify_release(struct inode *ignored, struct file *file)
{
struct fsnotify_group *group = file->private_data;
- struct fanotify_response_event *re, *lre;
-
- pr_debug("%s: file=%p group=%p\n", __func__, file, group);
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ struct fanotify_response_event *re, *lre;
+
mutex_lock(&group->fanotify_data.access_mutex);
- group->fanotify_data.bypass_perm = true;
+ atomic_inc(&group->fanotify_data.bypass_perm);
list_for_each_entry_safe(re, lre, &group->fanotify_data.access_list, list) {
pr_debug("%s: found group=%p re=%p event=%p\n", __func__, group,
.release = fanotify_release,
.unlocked_ioctl = fanotify_ioctl,
.compat_ioctl = fanotify_ioctl,
+ .llseek = noop_llseek,
};
static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
__u32 mask,
unsigned int flags)
{
- __u32 oldmask;
+ __u32 oldmask = -1;
spin_lock(&fsn_mark->lock);
if (!(flags & FAN_MARK_IGNORED_MASK)) {
oldmask = fsn_mark->mask;
fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
} else {
- oldmask = fsn_mark->ignored_mask;
- fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask | mask));
+ __u32 tmask = fsn_mark->ignored_mask | mask;
+ fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
}
+
+ if (!(flags & FAN_MARK_ONDIR)) {
+ __u32 tmask = fsn_mark->ignored_mask | FAN_ONDIR;
+ fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
+ }
+
spin_unlock(&fsn_mark->lock);
return mask & ~oldmask;
{
struct fsnotify_mark *fsn_mark;
__u32 added;
+ int ret = 0;
fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
if (!fsn_mark) {
- int ret;
+ if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
+ return -ENOSPC;
fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!fsn_mark)
fsnotify_init_mark(fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(fsn_mark, group, NULL, mnt, 0);
- if (ret) {
- fanotify_free_mark(fsn_mark);
- return ret;
- }
+ if (ret)
+ goto err;
}
added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
- fsnotify_put_mark(fsn_mark);
+
if (added & ~mnt->mnt_fsnotify_mask)
fsnotify_recalc_vfsmount_mask(mnt);
-
- return 0;
+err:
+ fsnotify_put_mark(fsn_mark);
+ return ret;
}
static int fanotify_add_inode_mark(struct fsnotify_group *group,
{
struct fsnotify_mark *fsn_mark;
__u32 added;
+ int ret = 0;
pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
+ /*
+ * If some other task has this inode open for write we should not add
+ * an ignored mark, unless that ignored mark is supposed to survive
+ * modification changes anyway.
+ */
+ if ((flags & FAN_MARK_IGNORED_MASK) &&
+ !(flags & FAN_MARK_IGNORED_SURV_MODIFY) &&
+ (atomic_read(&inode->i_writecount) > 0))
+ return 0;
+
fsn_mark = fsnotify_find_inode_mark(group, inode);
if (!fsn_mark) {
- int ret;
+ if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
+ return -ENOSPC;
fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!fsn_mark)
fsnotify_init_mark(fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(fsn_mark, group, inode, NULL, 0);
- if (ret) {
- fanotify_free_mark(fsn_mark);
- return ret;
- }
+ if (ret)
+ goto err;
}
added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
- fsnotify_put_mark(fsn_mark);
+
if (added & ~inode->i_fsnotify_mask)
fsnotify_recalc_inode_mask(inode);
- return 0;
+err:
+ fsnotify_put_mark(fsn_mark);
+ return ret;
}
/* fanotify syscalls */
{
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);
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;
/* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */
group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
- if (IS_ERR(group))
+ if (IS_ERR(group)) {
+ free_uid(user);
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);
init_waitqueue_head(&group->fanotify_data.access_waitq);
INIT_LIST_HEAD(&group->fanotify_data.access_list);
+ atomic_set(&group->fanotify_data.bypass_perm, 0);
#endif
+ switch (flags & FAN_ALL_CLASS_BITS) {
+ case FAN_CLASS_NOTIF:
+ group->priority = FS_PRIO_0;
+ break;
+ case FAN_CLASS_CONTENT:
+ group->priority = FS_PRIO_1;
+ break;
+ case FAN_CLASS_PRE_CONTENT:
+ group->priority = FS_PRIO_2;
+ break;
+ default:
+ fd = -EINVAL;
+ goto out_put_group;
+ }
+
+ if (flags & FAN_UNLIMITED_QUEUE) {
+ fd = -EPERM;
+ if (!capable(CAP_SYS_ADMIN))
+ goto out_put_group;
+ group->max_events = UINT_MAX;
+ } else {
+ group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS;
+ }
+
+ if (flags & FAN_UNLIMITED_MARKS) {
+ fd = -EPERM;
+ if (!capable(CAP_SYS_ADMIN))
+ goto out_put_group;
+ group->fanotify_data.max_marks = UINT_MAX;
+ } else {
+ group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
+ }
fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
if (fd < 0)
if (flags & ~FAN_ALL_MARK_FLAGS)
return -EINVAL;
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
- case FAN_MARK_ADD:
+ case FAN_MARK_ADD: /* fallthrough */
case FAN_MARK_REMOVE:
+ if (!mask)
+ return -EINVAL;
case FAN_MARK_FLUSH:
break;
default:
return -EINVAL;
}
+
+ if (mask & FAN_ONDIR) {
+ flags |= FAN_MARK_ONDIR;
+ mask &= ~FAN_ONDIR;
+ }
+
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
if (mask & ~(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD))
#else
ret = -EINVAL;
if (unlikely(filp->f_op != &fanotify_fops))
goto fput_and_out;
+ group = filp->private_data;
+
+ /*
+ * group->priority == FS_PRIO_0 == FAN_CLASS_NOTIF. These are not
+ * allowed to set permissions events.
+ */
+ ret = -EINVAL;
+ if (mask & FAN_ALL_PERM_EVENTS &&
+ group->priority == FS_PRIO_0)
+ goto fput_and_out;
ret = fanotify_find_path(dfd, pathname, &path, flags);
if (ret)
inode = path.dentry->d_inode;
else
mnt = path.mnt;
- group = filp->private_data;
/* create/update an inode mark */
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
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