Messages in this thread | | | Date | Fri, 10 Jan 2014 07:53:41 +0800 | Subject | Re: [PATCH] vfs: Fix possible NULL pointer dereference in inode_permission() | From | Linus Torvalds <> |
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On Fri, Jan 10, 2014 at 7:37 AM, Eric Paris <eparis@redhat.com> wrote: > > but at least from an SELinux PoV, I think it's quick and easy, but wrong > for maintainability...
Yeah, it's a hack, and it's wrong, and we should figure out how to do it right. Likely we should just tie the lifetime of the i_security member directly to the lifetime of the inode itself, and just make the rule be that security_inode_free() gets called from whatever frees the inode itself, and *not* have an extra rcu callback etc. But that sounds like a bigger change than I'm comfy with right now, so the hacky one might be the band-aid to do for stable..
The problem, of course, is that all the different filesystems have their own inode allocations/freeing. Of course, they all tend to share the same pattern ("call_rcu xyz_i_callback"), so maybe we could try to make that a more generic thing? Like have a "free_inode" vfs callback, and do the call_rcu delaying at the VFS level..
And maybe, just maybe, we could just say that that is what "destroy_inode()" is, and that we will just call it from rcu context. All the IO has hopefully been done earlier Yes/no?
Linus
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