diff options
Diffstat (limited to 'fs/notify/fanotify/fanotify_user.c')
-rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 220 |
1 files changed, 145 insertions, 75 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 0aa362b88550..42cb794c62ac 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -46,32 +46,53 @@ extern const struct fsnotify_ops fanotify_fsnotify_ops; struct kmem_cache *fanotify_mark_cache __read_mostly; -struct kmem_cache *fanotify_event_cachep __read_mostly; +struct kmem_cache *fanotify_fid_event_cachep __read_mostly; +struct kmem_cache *fanotify_path_event_cachep __read_mostly; struct kmem_cache *fanotify_perm_event_cachep __read_mostly; #define FANOTIFY_EVENT_ALIGN 4 +#define FANOTIFY_INFO_HDR_LEN \ + (sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle)) + +static int fanotify_fid_info_len(int fh_len, int name_len) +{ + int info_len = fh_len; + + if (name_len) + info_len += name_len + 1; + + return roundup(FANOTIFY_INFO_HDR_LEN + info_len, FANOTIFY_EVENT_ALIGN); +} static int fanotify_event_info_len(struct fanotify_event *event) { - if (!fanotify_event_has_fid(event)) - return 0; + int info_len = 0; + int fh_len = fanotify_event_object_fh_len(event); + + if (fh_len) + info_len += fanotify_fid_info_len(fh_len, 0); - return roundup(sizeof(struct fanotify_event_info_fid) + - sizeof(struct file_handle) + event->fh_len, - FANOTIFY_EVENT_ALIGN); + if (fanotify_event_name_len(event)) { + struct fanotify_name_event *fne = FANOTIFY_NE(event); + + info_len += fanotify_fid_info_len(fne->dir_fh.len, + fne->name_len); + } + + return info_len; } /* - * Get an fsnotify notification event if one exists and is small + * Get an fanotify notification event if one exists and is small * enough to fit in "count". Return an error pointer if the count * is not large enough. When permission event is dequeued, its state is * updated accordingly. */ -static struct fsnotify_event *get_one_event(struct fsnotify_group *group, +static struct fanotify_event *get_one_event(struct fsnotify_group *group, size_t count) { size_t event_size = FAN_EVENT_METADATA_LEN; - struct fsnotify_event *fsn_event = NULL; + struct fanotify_event *event = NULL; pr_debug("%s: group=%p count=%zd\n", __func__, group, count); @@ -85,26 +106,23 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, } if (event_size > count) { - fsn_event = ERR_PTR(-EINVAL); + event = ERR_PTR(-EINVAL); goto out; } - fsn_event = fsnotify_remove_first_event(group); - if (fanotify_is_perm_event(FANOTIFY_E(fsn_event)->mask)) - FANOTIFY_PE(fsn_event)->state = FAN_EVENT_REPORTED; + event = FANOTIFY_E(fsnotify_remove_first_event(group)); + if (fanotify_is_perm_event(event->mask)) + FANOTIFY_PERM(event)->state = FAN_EVENT_REPORTED; out: spin_unlock(&group->notification_lock); - return fsn_event; + return event; } -static int create_fd(struct fsnotify_group *group, - struct fanotify_event *event, +static int create_fd(struct fsnotify_group *group, struct path *path, 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; @@ -113,14 +131,9 @@ static int create_fd(struct fsnotify_group *group, * 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); + new_file = dentry_open(path, + group->fanotify_data.f_flags | FMODE_NONOTIFY, + current_cred()); if (IS_ERR(new_file)) { /* * we still send an event even if we can't open the file. this @@ -204,83 +217,111 @@ static int process_access_response(struct fsnotify_group *group, return -ENOENT; } -static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) +static int copy_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, + const char *name, size_t name_len, + char __user *buf, size_t count) { struct fanotify_event_info_fid info = { }; struct file_handle handle = { }; - unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh; - size_t fh_len = event->fh_len; - size_t len = fanotify_event_info_len(event); + unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh_buf; + size_t fh_len = fh ? fh->len : 0; + size_t info_len = fanotify_fid_info_len(fh_len, name_len); + size_t len = info_len; + + pr_debug("%s: fh_len=%zu name_len=%zu, info_len=%zu, count=%zu\n", + __func__, fh_len, name_len, info_len, count); - if (!len) + if (!fh_len || (name && !name_len)) return 0; - if (WARN_ON_ONCE(len < sizeof(info) + sizeof(handle) + fh_len)) + if (WARN_ON_ONCE(len < sizeof(info) || len > count)) return -EFAULT; - /* Copy event info fid header followed by vaiable sized file handle */ - info.hdr.info_type = FAN_EVENT_INFO_TYPE_FID; + /* + * Copy event info fid header followed by variable sized file handle + * and optionally followed by variable sized filename. + */ + info.hdr.info_type = name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME : + FAN_EVENT_INFO_TYPE_FID; info.hdr.len = len; - info.fsid = event->fid.fsid; + info.fsid = *fsid; if (copy_to_user(buf, &info, sizeof(info))) return -EFAULT; buf += sizeof(info); len -= sizeof(info); - handle.handle_type = event->fh_type; + if (WARN_ON_ONCE(len < sizeof(handle))) + return -EFAULT; + + handle.handle_type = fh->type; handle.handle_bytes = fh_len; if (copy_to_user(buf, &handle, sizeof(handle))) return -EFAULT; buf += sizeof(handle); len -= sizeof(handle); + if (WARN_ON_ONCE(len < fh_len)) + return -EFAULT; + /* - * For an inline fh, copy through stack to exclude the copy from - * usercopy hardening protections. + * For an inline fh and inline file name, copy through stack to exclude + * the copy from usercopy hardening protections. */ - fh = fanotify_event_fh(event); + fh_buf = fanotify_fh_buf(fh); if (fh_len <= FANOTIFY_INLINE_FH_LEN) { - memcpy(bounce, fh, fh_len); - fh = bounce; + memcpy(bounce, fh_buf, fh_len); + fh_buf = bounce; } - if (copy_to_user(buf, fh, fh_len)) + if (copy_to_user(buf, fh_buf, fh_len)) return -EFAULT; - /* Pad with 0's */ buf += fh_len; len -= fh_len; + + if (name_len) { + /* Copy the filename with terminating null */ + name_len++; + if (WARN_ON_ONCE(len < name_len)) + return -EFAULT; + + if (copy_to_user(buf, name, name_len)) + return -EFAULT; + + buf += name_len; + len -= name_len; + } + + /* Pad with 0's */ WARN_ON_ONCE(len < 0 || len >= FANOTIFY_EVENT_ALIGN); if (len > 0 && clear_user(buf, len)) return -EFAULT; - return 0; + return info_len; } static ssize_t copy_event_to_user(struct fsnotify_group *group, - struct fsnotify_event *fsn_event, + struct fanotify_event *event, char __user *buf, size_t count) { struct fanotify_event_metadata metadata; - struct fanotify_event *event; + struct path *path = fanotify_event_path(event); struct file *f = NULL; int ret, fd = FAN_NOFD; - pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event); + pr_debug("%s: group=%p event=%p\n", __func__, group, event); - event = container_of(fsn_event, struct fanotify_event, fse); - metadata.event_len = FAN_EVENT_METADATA_LEN; + metadata.event_len = FAN_EVENT_METADATA_LEN + + fanotify_event_info_len(event); metadata.metadata_len = FAN_EVENT_METADATA_LEN; metadata.vers = FANOTIFY_METADATA_VERSION; metadata.reserved = 0; metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS; metadata.pid = pid_vnr(event->pid); - if (fanotify_event_has_path(event)) { - fd = create_fd(group, event, &f); + if (path && path->mnt && path->dentry) { + fd = create_fd(group, path, &f); if (fd < 0) return fd; - } else if (fanotify_event_has_fid(event)) { - metadata.event_len += fanotify_event_info_len(event); } metadata.fd = fd; @@ -295,15 +336,39 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN)) goto out_close_fd; + buf += FAN_EVENT_METADATA_LEN; + count -= FAN_EVENT_METADATA_LEN; + if (fanotify_is_perm_event(event->mask)) - FANOTIFY_PE(fsn_event)->fd = fd; + FANOTIFY_PERM(event)->fd = fd; - if (fanotify_event_has_path(event)) { + if (f) fd_install(fd, f); - } else if (fanotify_event_has_fid(event)) { - ret = copy_fid_to_user(event, buf + FAN_EVENT_METADATA_LEN); + + /* Event info records order is: dir fid + name, child fid */ + if (fanotify_event_name_len(event)) { + struct fanotify_name_event *fne = FANOTIFY_NE(event); + + ret = copy_info_to_user(fanotify_event_fsid(event), + fanotify_event_dir_fh(event), + fne->name, fne->name_len, + buf, count); + if (ret < 0) + return ret; + + buf += ret; + count -= ret; + } + + if (fanotify_event_object_fh_len(event)) { + ret = copy_info_to_user(fanotify_event_fsid(event), + fanotify_event_object_fh(event), + NULL, 0, buf, count); if (ret < 0) return ret; + + buf += ret; + count -= ret; } return metadata.event_len; @@ -335,7 +400,7 @@ 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; + struct fanotify_event *event; char __user *start; int ret; DEFINE_WAIT_FUNC(wait, woken_wake_function); @@ -347,13 +412,13 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, add_wait_queue(&group->notification_waitq, &wait); while (1) { - kevent = get_one_event(group, count); - if (IS_ERR(kevent)) { - ret = PTR_ERR(kevent); + event = get_one_event(group, count); + if (IS_ERR(event)) { + ret = PTR_ERR(event); break; } - if (!kevent) { + if (!event) { ret = -EAGAIN; if (file->f_flags & O_NONBLOCK) break; @@ -369,7 +434,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, continue; } - ret = copy_event_to_user(group, kevent, buf, count); + ret = copy_event_to_user(group, event, buf, count); if (unlikely(ret == -EOPENSTALE)) { /* * We cannot report events with stale fd so drop it. @@ -384,17 +449,17 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, * Permission events get queued to wait for response. Other * events can be destroyed now. */ - if (!fanotify_is_perm_event(FANOTIFY_E(kevent)->mask)) { - fsnotify_destroy_event(group, kevent); + if (!fanotify_is_perm_event(event->mask)) { + fsnotify_destroy_event(group, &event->fse); } else { if (ret <= 0) { spin_lock(&group->notification_lock); finish_permission_event(group, - FANOTIFY_PE(kevent), FAN_DENY); + FANOTIFY_PERM(event), FAN_DENY); wake_up(&group->fanotify_data.access_waitq); } else { spin_lock(&group->notification_lock); - list_add_tail(&kevent->list, + list_add_tail(&event->fse.list, &group->fanotify_data.access_list); spin_unlock(&group->notification_lock); } @@ -440,8 +505,6 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t static int fanotify_release(struct inode *ignored, struct file *file) { struct fsnotify_group *group = file->private_data; - struct fanotify_perm_event *event; - struct fsnotify_event *fsn_event; /* * Stop new events from arriving in the notification queue. since @@ -456,6 +519,8 @@ static int fanotify_release(struct inode *ignored, struct file *file) */ spin_lock(&group->notification_lock); while (!list_empty(&group->fanotify_data.access_list)) { + struct fanotify_perm_event *event; + event = list_first_entry(&group->fanotify_data.access_list, struct fanotify_perm_event, fae.fse.list); list_del_init(&event->fae.fse.list); @@ -469,12 +534,14 @@ static int fanotify_release(struct inode *ignored, struct file *file) * response is consumed and fanotify_get_response() returns. */ while (!fsnotify_notify_queue_is_empty(group)) { - fsn_event = fsnotify_remove_first_event(group); - if (!(FANOTIFY_E(fsn_event)->mask & FANOTIFY_PERM_EVENTS)) { + struct fanotify_event *event; + + event = FANOTIFY_E(fsnotify_remove_first_event(group)); + if (!(event->mask & FANOTIFY_PERM_EVENTS)) { spin_unlock(&group->notification_lock); - fsnotify_destroy_event(group, fsn_event); + fsnotify_destroy_event(group, &event->fse); } else { - finish_permission_event(group, FANOTIFY_PE(fsn_event), + finish_permission_event(group, FANOTIFY_PERM(event), FAN_ALLOW); } spin_lock(&group->notification_lock); @@ -824,7 +891,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) group->memcg = get_mem_cgroup_from_mm(current->mm); oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL, - FSNOTIFY_EVENT_NONE, NULL); + FSNOTIFY_EVENT_NONE, NULL, NULL); if (unlikely(!oevent)) { fd = -ENOMEM; goto out_destroy_group; @@ -1139,7 +1206,10 @@ static int __init fanotify_user_setup(void) fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC|SLAB_ACCOUNT); - fanotify_event_cachep = KMEM_CACHE(fanotify_event, SLAB_PANIC); + fanotify_fid_event_cachep = KMEM_CACHE(fanotify_fid_event, + SLAB_PANIC); + fanotify_path_event_cachep = KMEM_CACHE(fanotify_path_event, + SLAB_PANIC); if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) { fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event, SLAB_PANIC); |