Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 24 Jan 2024 09:21:14 -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 09:10:58AM -0800, Linus Torvalds wrote: > On Wed, 24 Jan 2024 at 08:54, Linus Torvalds > <torvalds@linux-foundation.org> wrote: > > > > Hmm. That whole thing is disgusting. I think it should have checked > > FMODE_EXEC, and I have no idea why it doesn't. > > Maybe because FMODE_EXEC gets set for uselib() calls too? I dunno. I > think it would be even better if we had the 'intent' flags from > 'struct open_flags' available, but they aren't there in the > file_open() security chain.
I think there were other problems that I might have already fixed when I reorganized things in commit 0fd338b2d2cd ("exec: move path_noexec() check earlier") to more correctly map to LSM checks.
> Anyway, moving current->in_execve earlier looks fairly trivial, but I > worry about the randomness. I'd be *so*( much happier if this crazy > flag went away, and it got changed to look at the open intent instead. > > Attached patch is ENTIRELY UNTESTED. And disgusting.
I opted to tie "current->in_execve" lifetime to bprm lifetime just to have a clean boundary (i.e. strictly in alloc/free_bprm()).
-Kees
-- Kees Cook
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