Commit a3383e83 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify

* 'for-linus' of git://git.infradead.org/users/eparis/notify:
  fanotify: fill in the metadata_len field on struct fanotify_event_metadata
  fanotify: split version into version and metadata_len
  fanotify: Dont try to open a file descriptor for the overflow event
  fanotify: Introduce FAN_NOFD
  fanotify: do not leak user reference on allocation failure
  inotify: stop kernel memory leak on file creation failure
  fanotify: on group destroy allow all waiters to bypass permission check
  fanotify: Dont allow a mask of 0 if setting or removing a mark
  fanotify: correct broken ref counting in case adding a mark failed
  fanotify: if set by user unset FMODE_NONOTIFY before fsnotify_perm() is called
  fanotify: remove packed from access response message
  fanotify: deny permissions when no event was sent
parents 68a4ec9c 7d131623
......@@ -1748,6 +1748,9 @@ struct file *do_filp_open(int dfd, const char *pathname,
if (!(open_flag & O_CREAT))
mode = 0;
/* Must never be set by userspace */
open_flag &= ~FMODE_NONOTIFY;
/*
* O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
* check for O_DSYNC if the need any syncing at all we enforce it's
......
......@@ -92,7 +92,11 @@ static int fanotify_get_response_from_access(struct fsnotify_group *group,
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
wait_event(group->fanotify_data.access_waitq, event->response);
wait_event(group->fanotify_data.access_waitq, event->response ||
atomic_read(&group->fanotify_data.bypass_perm));
if (!event->response) /* bypass_perm set */
return 0;
/* userspace responded, convert to something usable */
spin_lock(&event->lock);
......
......@@ -106,20 +106,29 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
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);
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
......@@ -200,7 +209,7 @@ static int prepare_for_access_response(struct fsnotify_group *group,
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;
......@@ -257,24 +266,34 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
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:
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;
}
......@@ -382,7 +401,7 @@ static int fanotify_release(struct inode *ignored, struct file *file)
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,
......@@ -586,11 +605,10 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
{
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;
......@@ -600,17 +618,16 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
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,
......@@ -619,6 +636,7 @@ 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);
......@@ -634,8 +652,6 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
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;
......@@ -645,16 +661,16 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
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 */
......@@ -687,8 +703,10 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
/* 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);
......@@ -698,6 +716,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
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:
......@@ -764,8 +783,10 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
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:
......
......@@ -752,6 +752,7 @@ SYSCALL_DEFINE1(inotify_init1, int, flags)
if (ret >= 0)
return ret;
fsnotify_put_group(group);
atomic_dec(&user->inotify_devs);
out_free_uid:
free_uid(user);
......
......@@ -83,11 +83,13 @@
FAN_ALL_PERM_EVENTS |\
FAN_Q_OVERFLOW)
#define FANOTIFY_METADATA_VERSION 2
#define FANOTIFY_METADATA_VERSION 3
struct fanotify_event_metadata {
__u32 event_len;
__u32 vers;
__u8 vers;
__u8 reserved;
__u16 metadata_len;
__aligned_u64 mask;
__s32 fd;
__s32 pid;
......@@ -96,11 +98,13 @@ struct fanotify_event_metadata {
struct fanotify_response {
__s32 fd;
__u32 response;
} __attribute__ ((packed));
};
/* Legit userspace responses to a _PERM event */
#define FAN_ALLOW 0x01
#define FAN_DENY 0x02
/* No fd set in event */
#define FAN_NOFD -1
/* Helper functions to deal with fanotify_event_metadata buffers */
#define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata))
......
......@@ -235,9 +235,6 @@ static inline void fsnotify_open(struct file *file)
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
/* FMODE_NONOTIFY must never be set from user */
file->f_mode &= ~FMODE_NONOTIFY;
fsnotify_parent(path, NULL, mask);
fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
}
......
......@@ -166,7 +166,7 @@ struct fsnotify_group {
struct mutex access_mutex;
struct list_head access_list;
wait_queue_head_t access_waitq;
bool bypass_perm; /* protected by access_mutex */
atomic_t bypass_perm;
#endif /* CONFIG_FANOTIFY_ACCESS_PERMISSIONS */
int f_flags;
unsigned int max_marks;
......
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