Messages in this thread | | | Date | Fri, 8 Dec 2017 22:49:45 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: x86/ldt: Prevent ldt inheritance on exec |
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On Fri, 8 Dec 2017, Linus Torvalds wrote:
> On Fri, Dec 8, 2017 at 12:02 PM, Thomas Gleixner <tglx@linutronix.de> wrote: > > > > The reason why this happens is that init_new_context_ldt() is called from > > init_new_context() which obviously needs to be called for both fork() and > > exec(). > > > > It would be surprising if anything relies on that behaviour, so it seems to > > be safe to remove that misfeature. > > Looks sane. That said, can't we separate this out into the copy_mm() > phase only? > > We have "arch_dup_mmap()" that is called on fork() only, so that could > do the LDT copy from the old mm, and the actual init_new_context would > just zero it out. > > Then there wouldn't be any odd "check if this is an execve" because > the copying would be done in the right place.
Yes, that should work. It just needs to change arch_dup_mmap() so it can return an error code.
Thanks,
tglx
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