Linus Torvalds <[email protected]> writes: > On Thu, Sep 28, 2017 at 6:53 PM, Mimi Zohar <[email protected]> wrote: >> >> The locking issue isn't with validating the file hash, but with the >> setxattr, chmod, chown syscalls. Each of these syscalls takes the >> i_rwsem exclusively before IMA (or EVM) is called. > > Read my email again. > >> In setxattr, chmod, chown syscalls, IMA (and EVM) are called after the >> i_rwsem is already taken. So the locking would be: >> >> lock: i_rwsem >> lock: iint->mutex > > No. > > Two locks. One inner, one outer. Only the actual ones that calculates > the hash would take the outer one. Read my email.
That would require a task_work or another kind of work callback so that the writes of the xattr are not synchronous with the vfs callback correct? Eric
