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- #include <linux/fanotify.h>
- #include <linux/fcntl.h>
- #include <linux/file.h>
- #include <linux/fs.h>
- #include <linux/anon_inodes.h>
- #include <linux/fsnotify_backend.h>
- #include <linux/init.h>
- #include <linux/mount.h>
- #include <linux/namei.h>
- #include <linux/poll.h>
- #include <linux/security.h>
- #include <linux/syscalls.h>
- #include <linux/slab.h>
- #include <linux/types.h>
- #include <linux/uaccess.h>
- #include <linux/compat.h>
- #include <asm/ioctls.h>
- #include "../../mount.h"
- #include "../fdinfo.h"
- #include "fanotify.h"
- #define FANOTIFY_DEFAULT_MAX_EVENTS 16384
- #define FANOTIFY_DEFAULT_MAX_MARKS 8192
- #define FANOTIFY_DEFAULT_MAX_LISTENERS 128
- /*
- * All flags that may be specified in parameter event_f_flags of fanotify_init.
- *
- * Internal and external open flags are stored together in field f_flags of
- * struct file. Only external open flags shall be allowed in event_f_flags.
- * Internal flags like FMODE_NONOTIFY, FMODE_EXEC, FMODE_NOCMTIME shall be
- * excluded.
- */
- #define FANOTIFY_INIT_ALL_EVENT_F_BITS ( \
- O_ACCMODE | O_APPEND | O_NONBLOCK | \
- __O_SYNC | O_DSYNC | O_CLOEXEC | \
- O_LARGEFILE | O_NOATIME )
- extern const struct fsnotify_ops fanotify_fsnotify_ops;
- static struct kmem_cache *fanotify_mark_cache __read_mostly;
- struct kmem_cache *fanotify_event_cachep __read_mostly;
- struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
- /*
- * Get an fsnotify notification event if one exists and is small
- * enough to fit in "count". Return an error pointer if the count
- * is not large enough.
- *
- * Called with the group->notification_mutex held.
- */
- static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
- size_t count)
- {
- BUG_ON(!mutex_is_locked(&group->notification_mutex));
- pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
- if (fsnotify_notify_queue_is_empty(group))
- return NULL;
- if (FAN_EVENT_METADATA_LEN > count)
- return ERR_PTR(-EINVAL);
- /* held the notification_mutex the whole time, so this is the
- * same event we peeked above */
- return fsnotify_remove_first_event(group);
- }
- static int create_fd(struct fsnotify_group *group,
- struct fanotify_event_info *event,
- struct file **file)
- {
- int client_fd;
- struct file *new_file;
- pr_debug("%s: group=%p event=%p\n", __func__, group, event);
- client_fd = get_unused_fd_flags(group->fanotify_data.f_flags);
- if (client_fd < 0)
- return client_fd;
- /*
- * we need a new file handle for the userspace program so it can read even if it was
- * originally opened O_WRONLY.
- */
- /* it's possible this event was an overflow event. in that case dentry and mnt
- * are NULL; That's fine, just don't call dentry open */
- if (event->path.dentry && event->path.mnt)
- new_file = dentry_open(&event->path,
- group->fanotify_data.f_flags | FMODE_NONOTIFY,
- current_cred());
- else
- new_file = ERR_PTR(-EOVERFLOW);
- if (IS_ERR(new_file)) {
- /*
- * we still send an event even if we can't open the file. this
- * can happen when say tasks are gone and we try to open their
- * /proc files or we try to open a WRONLY file like in sysfs
- * we just send the errno to userspace since there isn't much
- * else we can do.
- */
- put_unused_fd(client_fd);
- client_fd = PTR_ERR(new_file);
- } else {
- *file = new_file;
- }
- return client_fd;
- }
- static int fill_event_metadata(struct fsnotify_group *group,
- struct fanotify_event_metadata *metadata,
- struct fsnotify_event *fsn_event,
- struct file **file)
- {
- int ret = 0;
- struct fanotify_event_info *event;
- pr_debug("%s: group=%p metadata=%p event=%p\n", __func__,
- group, metadata, fsn_event);
- *file = NULL;
- event = container_of(fsn_event, struct fanotify_event_info, fse);
- metadata->event_len = FAN_EVENT_METADATA_LEN;
- metadata->metadata_len = FAN_EVENT_METADATA_LEN;
- metadata->vers = FANOTIFY_METADATA_VERSION;
- metadata->reserved = 0;
- metadata->mask = fsn_event->mask & FAN_ALL_OUTGOING_EVENTS;
- metadata->pid = pid_vnr(event->tgid);
- if (unlikely(fsn_event->mask & FAN_Q_OVERFLOW))
- metadata->fd = FAN_NOFD;
- else {
- metadata->fd = create_fd(group, event, file);
- if (metadata->fd < 0)
- ret = metadata->fd;
- }
- return ret;
- }
- #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- static struct fanotify_perm_event_info *dequeue_event(
- struct fsnotify_group *group, int fd)
- {
- struct fanotify_perm_event_info *event, *return_e = NULL;
- spin_lock(&group->fanotify_data.access_lock);
- list_for_each_entry(event, &group->fanotify_data.access_list,
- fae.fse.list) {
- if (event->fd != fd)
- continue;
- list_del_init(&event->fae.fse.list);
- return_e = event;
- break;
- }
- spin_unlock(&group->fanotify_data.access_lock);
- pr_debug("%s: found return_re=%p\n", __func__, return_e);
- return return_e;
- }
- static int process_access_response(struct fsnotify_group *group,
- struct fanotify_response *response_struct)
- {
- struct fanotify_perm_event_info *event;
- int fd = response_struct->fd;
- int response = response_struct->response;
- pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group,
- fd, response);
- /*
- * make sure the response is valid, if invalid we do nothing and either
- * userspace can send a valid response or we will clean it up after the
- * timeout
- */
- switch (response) {
- case FAN_ALLOW:
- case FAN_DENY:
- break;
- default:
- return -EINVAL;
- }
- if (fd < 0)
- return -EINVAL;
- event = dequeue_event(group, fd);
- if (!event)
- return -ENOENT;
- event->response = response;
- wake_up(&group->fanotify_data.access_waitq);
- return 0;
- }
- #endif
- static ssize_t copy_event_to_user(struct fsnotify_group *group,
- struct fsnotify_event *event,
- char __user *buf)
- {
- struct fanotify_event_metadata fanotify_event_metadata;
- struct file *f;
- int fd, ret;
- pr_debug("%s: group=%p event=%p\n", __func__, group, event);
- ret = fill_event_metadata(group, &fanotify_event_metadata, event, &f);
- if (ret < 0)
- return ret;
- fd = fanotify_event_metadata.fd;
- ret = -EFAULT;
- if (copy_to_user(buf, &fanotify_event_metadata,
- fanotify_event_metadata.event_len))
- goto out_close_fd;
- #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- if (event->mask & FAN_ALL_PERM_EVENTS)
- FANOTIFY_PE(event)->fd = fd;
- #endif
- if (fd != FAN_NOFD)
- fd_install(fd, f);
- return fanotify_event_metadata.event_len;
- out_close_fd:
- if (fd != FAN_NOFD) {
- put_unused_fd(fd);
- fput(f);
- }
- return ret;
- }
- /* intofiy userspace file descriptor functions */
- static unsigned int fanotify_poll(struct file *file, poll_table *wait)
- {
- struct fsnotify_group *group = file->private_data;
- int ret = 0;
- poll_wait(file, &group->notification_waitq, wait);
- mutex_lock(&group->notification_mutex);
- if (!fsnotify_notify_queue_is_empty(group))
- ret = POLLIN | POLLRDNORM;
- mutex_unlock(&group->notification_mutex);
- return ret;
- }
- static ssize_t fanotify_read(struct file *file, char __user *buf,
- size_t count, loff_t *pos)
- {
- struct fsnotify_group *group;
- struct fsnotify_event *kevent;
- char __user *start;
- int ret;
- DEFINE_WAIT_FUNC(wait, woken_wake_function);
- start = buf;
- group = file->private_data;
- pr_debug("%s: group=%p\n", __func__, group);
- add_wait_queue(&group->notification_waitq, &wait);
- while (1) {
- mutex_lock(&group->notification_mutex);
- kevent = get_one_event(group, count);
- mutex_unlock(&group->notification_mutex);
- if (IS_ERR(kevent)) {
- ret = PTR_ERR(kevent);
- break;
- }
- if (!kevent) {
- ret = -EAGAIN;
- if (file->f_flags & O_NONBLOCK)
- break;
- ret = -ERESTARTSYS;
- if (signal_pending(current))
- break;
- if (start != buf)
- break;
- wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
- continue;
- }
- ret = copy_event_to_user(group, kevent, buf);
- /*
- * Permission events get queued to wait for response. Other
- * events can be destroyed now.
- */
- if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) {
- fsnotify_destroy_event(group, kevent);
- if (ret < 0)
- break;
- } else {
- #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- if (ret < 0) {
- FANOTIFY_PE(kevent)->response = FAN_DENY;
- wake_up(&group->fanotify_data.access_waitq);
- break;
- }
- spin_lock(&group->fanotify_data.access_lock);
- list_add_tail(&kevent->list,
- &group->fanotify_data.access_list);
- spin_unlock(&group->fanotify_data.access_lock);
- #endif
- }
- buf += ret;
- count -= ret;
- }
- remove_wait_queue(&group->notification_waitq, &wait);
- if (start != buf && ret != -EFAULT)
- ret = buf - start;
- return ret;
- }
- static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
- {
- #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- struct fanotify_response response = { .fd = -1, .response = -1 };
- struct fsnotify_group *group;
- int ret;
- group = file->private_data;
- if (count > sizeof(response))
- count = sizeof(response);
- pr_debug("%s: group=%p count=%zu\n", __func__, group, count);
- if (copy_from_user(&response, buf, count))
- return -EFAULT;
- ret = process_access_response(group, &response);
- if (ret < 0)
- count = ret;
- return count;
- #else
- return -EINVAL;
- #endif
- }
- static int fanotify_release(struct inode *ignored, struct file *file)
- {
- struct fsnotify_group *group = file->private_data;
- #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- struct fanotify_perm_event_info *event, *next;
- struct fsnotify_event *fsn_event;
- /*
- * Stop new events from arriving in the notification queue. since
- * userspace cannot use fanotify fd anymore, no event can enter or
- * leave access_list by now either.
- */
- fsnotify_group_stop_queueing(group);
- /*
- * Process all permission events on access_list and notification queue
- * and simulate reply from userspace.
- */
- spin_lock(&group->fanotify_data.access_lock);
- list_for_each_entry_safe(event, next, &group->fanotify_data.access_list,
- fae.fse.list) {
- pr_debug("%s: found group=%p event=%p\n", __func__, group,
- event);
- list_del_init(&event->fae.fse.list);
- event->response = FAN_ALLOW;
- }
- spin_unlock(&group->fanotify_data.access_lock);
- /*
- * Destroy all non-permission events. For permission events just
- * dequeue them and set the response. They will be freed once the
- * response is consumed and fanotify_get_response() returns.
- */
- mutex_lock(&group->notification_mutex);
- while (!fsnotify_notify_queue_is_empty(group)) {
- fsn_event = fsnotify_remove_first_event(group);
- if (!(fsn_event->mask & FAN_ALL_PERM_EVENTS))
- fsnotify_destroy_event(group, fsn_event);
- else
- FANOTIFY_PE(fsn_event)->response = FAN_ALLOW;
- }
- mutex_unlock(&group->notification_mutex);
- /* Response for all permission events it set, wakeup waiters */
- wake_up(&group->fanotify_data.access_waitq);
- #endif
- /* matches the fanotify_init->fsnotify_alloc_group */
- fsnotify_destroy_group(group);
- return 0;
- }
- static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
- {
- struct fsnotify_group *group;
- struct fsnotify_event *fsn_event;
- void __user *p;
- int ret = -ENOTTY;
- size_t send_len = 0;
- group = file->private_data;
- p = (void __user *) arg;
- switch (cmd) {
- case FIONREAD:
- mutex_lock(&group->notification_mutex);
- list_for_each_entry(fsn_event, &group->notification_list, list)
- send_len += FAN_EVENT_METADATA_LEN;
- mutex_unlock(&group->notification_mutex);
- ret = put_user(send_len, (int __user *) p);
- break;
- }
- return ret;
- }
- static const struct file_operations fanotify_fops = {
- .show_fdinfo = fanotify_show_fdinfo,
- .poll = fanotify_poll,
- .read = fanotify_read,
- .write = fanotify_write,
- .fasync = NULL,
- .release = fanotify_release,
- .unlocked_ioctl = fanotify_ioctl,
- .compat_ioctl = fanotify_ioctl,
- .llseek = noop_llseek,
- };
- static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
- {
- kmem_cache_free(fanotify_mark_cache, fsn_mark);
- }
- static int fanotify_find_path(int dfd, const char __user *filename,
- struct path *path, unsigned int flags)
- {
- int ret;
- pr_debug("%s: dfd=%d filename=%p flags=%x\n", __func__,
- dfd, filename, flags);
- if (filename == NULL) {
- struct fd f = fdget(dfd);
- ret = -EBADF;
- if (!f.file)
- goto out;
- ret = -ENOTDIR;
- if ((flags & FAN_MARK_ONLYDIR) &&
- !(S_ISDIR(file_inode(f.file)->i_mode))) {
- fdput(f);
- goto out;
- }
- *path = f.file->f_path;
- path_get(path);
- fdput(f);
- } else {
- unsigned int lookup_flags = 0;
- if (!(flags & FAN_MARK_DONT_FOLLOW))
- lookup_flags |= LOOKUP_FOLLOW;
- if (flags & FAN_MARK_ONLYDIR)
- lookup_flags |= LOOKUP_DIRECTORY;
- ret = user_path_at(dfd, filename, lookup_flags, path);
- if (ret)
- goto out;
- }
- /* you can only watch an inode if you have read permissions on it */
- ret = inode_permission(path->dentry->d_inode, MAY_READ);
- if (ret)
- path_put(path);
- out:
- return ret;
- }
- static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
- __u32 mask,
- unsigned int flags,
- int *destroy)
- {
- __u32 oldmask = 0;
- spin_lock(&fsn_mark->lock);
- if (!(flags & FAN_MARK_IGNORED_MASK)) {
- __u32 tmask = fsn_mark->mask & ~mask;
- if (flags & FAN_MARK_ONDIR)
- tmask &= ~FAN_ONDIR;
- oldmask = fsn_mark->mask;
- fsnotify_set_mark_mask_locked(fsn_mark, tmask);
- } else {
- __u32 tmask = fsn_mark->ignored_mask & ~mask;
- if (flags & FAN_MARK_ONDIR)
- tmask &= ~FAN_ONDIR;
- fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
- }
- *destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
- spin_unlock(&fsn_mark->lock);
- return mask & oldmask;
- }
- static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
- struct vfsmount *mnt, __u32 mask,
- unsigned int flags)
- {
- struct fsnotify_mark *fsn_mark = NULL;
- __u32 removed;
- int destroy_mark;
- mutex_lock(&group->mark_mutex);
- fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
- if (!fsn_mark) {
- mutex_unlock(&group->mark_mutex);
- return -ENOENT;
- }
- removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags,
- &destroy_mark);
- if (destroy_mark)
- fsnotify_detach_mark(fsn_mark);
- mutex_unlock(&group->mark_mutex);
- if (destroy_mark)
- fsnotify_free_mark(fsn_mark);
- fsnotify_put_mark(fsn_mark);
- if (removed & real_mount(mnt)->mnt_fsnotify_mask)
- fsnotify_recalc_vfsmount_mask(mnt);
- return 0;
- }
- static int fanotify_remove_inode_mark(struct fsnotify_group *group,
- struct inode *inode, __u32 mask,
- unsigned int flags)
- {
- struct fsnotify_mark *fsn_mark = NULL;
- __u32 removed;
- int destroy_mark;
- mutex_lock(&group->mark_mutex);
- fsn_mark = fsnotify_find_inode_mark(group, inode);
- if (!fsn_mark) {
- mutex_unlock(&group->mark_mutex);
- return -ENOENT;
- }
- removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags,
- &destroy_mark);
- if (destroy_mark)
- fsnotify_detach_mark(fsn_mark);
- mutex_unlock(&group->mark_mutex);
- if (destroy_mark)
- fsnotify_free_mark(fsn_mark);
- /* matches the fsnotify_find_inode_mark() */
- fsnotify_put_mark(fsn_mark);
- if (removed & inode->i_fsnotify_mask)
- fsnotify_recalc_inode_mask(inode);
- return 0;
- }
- static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
- __u32 mask,
- unsigned int flags)
- {
- __u32 oldmask = -1;
- spin_lock(&fsn_mark->lock);
- if (!(flags & FAN_MARK_IGNORED_MASK)) {
- __u32 tmask = fsn_mark->mask | mask;
- if (flags & FAN_MARK_ONDIR)
- tmask |= FAN_ONDIR;
- oldmask = fsn_mark->mask;
- fsnotify_set_mark_mask_locked(fsn_mark, tmask);
- } else {
- __u32 tmask = fsn_mark->ignored_mask | mask;
- if (flags & FAN_MARK_ONDIR)
- tmask |= FAN_ONDIR;
- 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;
- }
- spin_unlock(&fsn_mark->lock);
- return mask & ~oldmask;
- }
- static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
- struct inode *inode,
- struct vfsmount *mnt)
- {
- struct fsnotify_mark *mark;
- int ret;
- if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
- return ERR_PTR(-ENOSPC);
- mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
- if (!mark)
- return ERR_PTR(-ENOMEM);
- fsnotify_init_mark(mark, fanotify_free_mark);
- ret = fsnotify_add_mark_locked(mark, group, inode, mnt, 0);
- if (ret) {
- fsnotify_put_mark(mark);
- return ERR_PTR(ret);
- }
- return mark;
- }
- static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
- struct vfsmount *mnt, __u32 mask,
- unsigned int flags)
- {
- struct fsnotify_mark *fsn_mark;
- __u32 added;
- mutex_lock(&group->mark_mutex);
- fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
- if (!fsn_mark) {
- fsn_mark = fanotify_add_new_mark(group, NULL, mnt);
- if (IS_ERR(fsn_mark)) {
- mutex_unlock(&group->mark_mutex);
- return PTR_ERR(fsn_mark);
- }
- }
- added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
- mutex_unlock(&group->mark_mutex);
- if (added & ~real_mount(mnt)->mnt_fsnotify_mask)
- fsnotify_recalc_vfsmount_mask(mnt);
- fsnotify_put_mark(fsn_mark);
- return 0;
- }
- static int fanotify_add_inode_mark(struct fsnotify_group *group,
- struct inode *inode, __u32 mask,
- unsigned int flags)
- {
- struct fsnotify_mark *fsn_mark;
- __u32 added;
- 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;
- mutex_lock(&group->mark_mutex);
- fsn_mark = fsnotify_find_inode_mark(group, inode);
- if (!fsn_mark) {
- fsn_mark = fanotify_add_new_mark(group, inode, NULL);
- if (IS_ERR(fsn_mark)) {
- mutex_unlock(&group->mark_mutex);
- return PTR_ERR(fsn_mark);
- }
- }
- added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
- mutex_unlock(&group->mark_mutex);
- if (added & ~inode->i_fsnotify_mask)
- fsnotify_recalc_inode_mask(inode);
- fsnotify_put_mark(fsn_mark);
- return 0;
- }
- /* fanotify syscalls */
- SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
- {
- struct fsnotify_group *group;
- int f_flags, fd;
- struct user_struct *user;
- struct fanotify_event_info *oevent;
- pr_debug("%s: flags=%d event_f_flags=%d\n",
- __func__, flags, event_f_flags);
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (flags & ~FAN_ALL_INIT_FLAGS)
- return -EINVAL;
- if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS)
- return -EINVAL;
- switch (event_f_flags & O_ACCMODE) {
- case O_RDONLY:
- case O_RDWR:
- case O_WRONLY:
- break;
- default:
- 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;
- if (flags & FAN_NONBLOCK)
- f_flags |= O_NONBLOCK;
- /* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */
- group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
- if (IS_ERR(group)) {
- free_uid(user);
- return PTR_ERR(group);
- }
- group->fanotify_data.user = user;
- atomic_inc(&user->fanotify_listeners);
- oevent = fanotify_alloc_event(NULL, FS_Q_OVERFLOW, NULL);
- if (unlikely(!oevent)) {
- fd = -ENOMEM;
- goto out_destroy_group;
- }
- group->overflow_event = &oevent->fse;
- if (force_o_largefile())
- event_f_flags |= O_LARGEFILE;
- group->fanotify_data.f_flags = event_f_flags;
- #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- spin_lock_init(&group->fanotify_data.access_lock);
- init_waitqueue_head(&group->fanotify_data.access_waitq);
- INIT_LIST_HEAD(&group->fanotify_data.access_list);
- #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_destroy_group;
- }
- if (flags & FAN_UNLIMITED_QUEUE) {
- fd = -EPERM;
- if (!capable(CAP_SYS_ADMIN))
- goto out_destroy_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_destroy_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)
- goto out_destroy_group;
- return fd;
- out_destroy_group:
- fsnotify_destroy_group(group);
- return fd;
- }
- SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
- __u64, mask, int, dfd,
- const char __user *, pathname)
- {
- struct inode *inode = NULL;
- struct vfsmount *mnt = NULL;
- struct fsnotify_group *group;
- struct fd f;
- struct path path;
- int ret;
- pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
- __func__, fanotify_fd, flags, dfd, pathname, mask);
- /* we only use the lower 32 bits as of right now. */
- if (mask & ((__u64)0xffffffff << 32))
- return -EINVAL;
- if (flags & ~FAN_ALL_MARK_FLAGS)
- return -EINVAL;
- switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
- case FAN_MARK_ADD: /* fallthrough */
- case FAN_MARK_REMOVE:
- if (!mask)
- return -EINVAL;
- break;
- case FAN_MARK_FLUSH:
- if (flags & ~(FAN_MARK_MOUNT | FAN_MARK_FLUSH))
- return -EINVAL;
- 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
- if (mask & ~(FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD))
- #endif
- return -EINVAL;
- f = fdget(fanotify_fd);
- if (unlikely(!f.file))
- return -EBADF;
- /* verify that this is indeed an fanotify instance */
- ret = -EINVAL;
- if (unlikely(f.file->f_op != &fanotify_fops))
- goto fput_and_out;
- group = f.file->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;
- if (flags & FAN_MARK_FLUSH) {
- ret = 0;
- if (flags & FAN_MARK_MOUNT)
- fsnotify_clear_vfsmount_marks_by_group(group);
- else
- fsnotify_clear_inode_marks_by_group(group);
- goto fput_and_out;
- }
- ret = fanotify_find_path(dfd, pathname, &path, flags);
- if (ret)
- goto fput_and_out;
- /* inode held in place by reference to path; group by fget on fd */
- if (!(flags & FAN_MARK_MOUNT))
- inode = path.dentry->d_inode;
- else
- mnt = path.mnt;
- /* create/update an inode mark */
- switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) {
- case FAN_MARK_ADD:
- if (flags & FAN_MARK_MOUNT)
- ret = fanotify_add_vfsmount_mark(group, mnt, mask, flags);
- else
- ret = fanotify_add_inode_mark(group, inode, mask, flags);
- break;
- case FAN_MARK_REMOVE:
- if (flags & FAN_MARK_MOUNT)
- ret = fanotify_remove_vfsmount_mark(group, mnt, mask, flags);
- else
- ret = fanotify_remove_inode_mark(group, inode, mask, flags);
- break;
- default:
- ret = -EINVAL;
- }
- path_put(&path);
- fput_and_out:
- fdput(f);
- return ret;
- }
- #ifdef CONFIG_COMPAT
- COMPAT_SYSCALL_DEFINE6(fanotify_mark,
- int, fanotify_fd, unsigned int, flags,
- __u32, mask0, __u32, mask1, int, dfd,
- const char __user *, pathname)
- {
- return sys_fanotify_mark(fanotify_fd, flags,
- #ifdef __BIG_ENDIAN
- ((__u64)mask0 << 32) | mask1,
- #else
- ((__u64)mask1 << 32) | mask0,
- #endif
- dfd, pathname);
- }
- #endif
- /*
- * fanotify_user_setup - Our initialization function. Note that we cannot return
- * error because we have compiled-in VFS hooks. So an (unlikely) failure here
- * must result in panic().
- */
- static int __init fanotify_user_setup(void)
- {
- fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
- fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC);
- #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info,
- SLAB_PANIC);
- #endif
- return 0;
- }
- device_initcall(fanotify_user_setup);
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