On Wed, 2018-12-12 at 19:02 -0800, Matthew Wilcox wrote: > On Wed, Dec 12, 2018 at 09:17:07AM +0100, Mickaël Salaün wrote: > > The goal of this patch series is to control script interpretation. A > > new O_MAYEXEC flag used by sys_open() is added to enable userland script > > interpreter to delegate to the kernel (and thus the system security > > policy) the permission to interpret scripts or other files containing > > what can be seen as commands. > > 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. Mimi
