Messages in this thread | | | Date | Wed, 24 Jan 2024 11:02:34 -0800 | From | Kees Cook <> | Subject | Re: [6.8-rc1 Regression] Unable to exec apparmor_parser from virt-aa-helper |
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On Wed, Jan 24, 2024 at 10:27:03AM -0800, Linus Torvalds wrote: > On Wed, 24 Jan 2024 at 09:27, Linus Torvalds > <torvalds@linux-foundation.org> wrote: > > > > IOW, I think the goal here should be "minimal fix" followed by "remove > > that horrendous thing". > > Ugh. The tomoyo use is even *more* disgusting, in how it uses it for > "tomoyo_domain()" entirely independently of even the ->file_open() > callback.
Yeah, I just sent a similar email.
> So for tomoyo, it's not about the file open, it's about > tomoyo_cred_prepare() and friends.
Yeah, it looks like it should happily follow cred lifetime, but I haven't fully convinced myself.
> So the patch I posted probably fixes apparmor, but only breaks tomoyo > instead, because tomoyo really does seem to use it around the whole > security_bprm_creds_for_exec() thing. > > Now, tomoyo *also* uses it for the file_open() callback, just to confuse things. > > IOW, I think the right thing to do is to split this in two: > > - leave the existing ->in_execve for the bprm_creds dance in > boprm_execve(). Horrendous and disgusing.
Agreed.
> - the ->file_open() thing is changed to check file->f_flags
Agreed. (And I've tested this for AppArmor now. I can confirm the failure case -- it's only for profile transitions, which is why I didn't see it originally in testing.
> IOW, I think the patch I posted earlier - and Kees' version of the > same thing - is just broken. This attached patch might work.
Yup. Should I post a formal patch, or do you want to commit what you've got (with the "file" -> "f" fix)?
-Kees
-- Kees Cook
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