From ebc14c4dbeb56195950058db9aa32de06c22de0d Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 16 Oct 2007 23:31:03 -0700 Subject: fuse: fix permission checking on sticky directories The VFS checks sticky bits on the parent directory even if the filesystem defines it's own ->permission(). In some situations (sshfs, mountlo, etc) the user does have permission to delete a file even if the attribute based checking would not allow it. So work around this by storing the permission bits separately and returning them in stat(), but cutting the permission bits off from inode->i_mode. This is slightly hackish, but it's probably not worth it to add new infrastructure in VFS and a slight performance penalty for all filesystems, just for the sake of fuse. [Jan Engelhardt] cosmetic fixes Signed-off-by: Miklos Szeredi Cc: Jan Engelhardt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/inode.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'fs/fuse/inode.c') diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 951e760d5c5a..fd0735715c14 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -120,10 +120,11 @@ static void fuse_truncate(struct address_space *mapping, loff_t offset) void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr) { struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_inode *fi = get_fuse_inode(inode); loff_t oldsize; inode->i_ino = attr->ino; - inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777); + inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); inode->i_nlink = attr->nlink; inode->i_uid = attr->uid; inode->i_gid = attr->gid; @@ -135,6 +136,15 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr) inode->i_ctime.tv_sec = attr->ctime; inode->i_ctime.tv_nsec = attr->ctimensec; + /* + * Don't set the sticky bit in i_mode, unless we want the VFS + * to check permissions. This prevents failures due to the + * check in may_delete(). + */ + fi->orig_i_mode = inode->i_mode; + if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS)) + inode->i_mode &= ~S_ISVTX; + spin_lock(&fc->lock); oldsize = inode->i_size; i_size_write(inode, attr->size); -- cgit v1.2.3