On Mon, Jun 15, 2020 at 10:42:12PM -0400, J. Bruce Fields wrote: > On Mon, Jun 15, 2020 at 10:38:20PM -0400, J. Bruce Fields wrote: > > Thanks for the detailed reproducer. > > > > It's weird, as the server is basically just setting the transmitted > > umask and then calling into the vfs to handle the rest, so it's not much > > different from any other user. But the same reproducer run just on the > > ext4 filesystem does give the right permissions.... > > > > Oh, but looking at the system call, fs_namei.c:do_mkdirat(), it does: > > > > if (!IS_POSIXACL(path.dentry->d_inode)) > > mode &= ~current_umask(); > > error = security_path_mkdir(&path, dentry, mode); > > if (!error) > > error = vfs_mkdir(path.dentry->d_inode, dentry, mode); > > > > whereas nfsd just calls into vfs_mkdir(). > > > > And that IS_POSIXACL() check is exactly a check whether the filesystem > > supports ACLs. So I guess it's the responsibility of the caller of > > vfs_mkdir() to handle that case. > > But, that's unsatisfying: why isn't vfs_mkdir() taking care of this > itself? And what about that security_path_mkdir() call? And are the > other cases of that switch in fs/nfsd/vfs.c:nfsd_create_locked() > correct? I think there may be some more cleanup here called for, I'll > poke around tomorrow. Yes agreed and can confirm: The other cases in fs/nfsd/vfs.c:nfsd_create_locked() seem to have the problem as well. Regards, Salvatore
