diff options
Diffstat (limited to 'fs/notify/fanotify/fanotify_user.c')
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 98 |
1 files changed, 90 insertions, 8 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index bbcb98e7fcc6..063224812b7e 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -16,6 +16,10 @@ #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; @@ -326,7 +330,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, ret = -EAGAIN; if (file->f_flags & O_NONBLOCK) break; - ret = -EINTR; + ret = -ERESTARTSYS; if (signal_pending(current)) break; @@ -372,11 +376,10 @@ 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_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; @@ -554,18 +557,24 @@ static __u32 fanotify_mark_add_to_mask(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; @@ -582,6 +591,9 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, 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) return -ENOMEM; @@ -610,10 +622,23 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group, 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) return -ENOMEM; @@ -637,6 +662,7 @@ 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); @@ -647,6 +673,12 @@ 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; @@ -658,12 +690,47 @@ 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); 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_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) @@ -704,6 +771,12 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags, 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 @@ -719,6 +792,16 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags, 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) @@ -729,7 +812,6 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags, 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)) { |