Hi Jann, On Tue, 2020-05-05 at 02:15 +0200, Jann Horn wrote: > On Mon, May 4, 2020 at 11:18 PM Mimi Zohar <zohar@xxxxxxxxxxxxx> wrote: > > Files can be mmap'ed read/write and later changed to execute to circumvent > > IMA's mmap appraise policy rules. Due to locking issues (mmap semaphore > > would be taken prior to i_mutex), files can not be measured or appraised at > > this point. Eliminate this integrity gap, by denying the mprotect > > PROT_EXECUTE change, if an mmap appraise policy rule exists. > > Just keep in mind that there are other ways to create executable > mappings containing controlled code; e.g. PROT_EXEC with > MAP_ANONYMOUS, or writing to /proc/self/mem (which is a debugging API > that works entirely without ever making the VMA writable - I had an > old series to provide LSM hooks for that stuff at > <https://lore.kernel.org/lkml/1478142286-18427-3-git-send-email-jann@xxxxxxxxx/>, > but I guess I must have forgotten about it or something...). Sure. These sound like memory attacks, which should be closed, but are probably out of scope for IMA. thanks, Mimi
