On Thu, Dec 13, 2018 at 06:04:20AM -0500, Mimi Zohar wrote: > > I don't have a problem with the concept, but we're running low on O_ bits. > > Does this have to be done before the process gets a file descriptor, > > or could we have a new syscall? Since we're going to be changing the > > interpreters anyway, it doesn't seem like too much of an imposition to > > ask them to use: > > > > int verify_for_exec(int fd) > > > > instead of adding an O_MAYEXEC. > > The indication needs to be set during file open, before the open > returns to the caller. This is the point where ima_file_check() > verifies the file's signature. On failure, access to the file is > denied. I understand that's what happens today, but do we need to do it that way? There's no harm in the interpreter having an fd to a file if it knows not to execute it. This is different from a program opening a file and having the LSM deny access to it because it violates the security model.
