Re: [patch 1/6] mmu_notifier: Core code

From: Robin Holt
Date: Tue Jan 29 2008 - 11:07:54 EST


I am going to seperate my comments into individual replies to help
reduce the chance they are lost.

> +void mmu_notifier_release(struct mm_struct *mm)
...
> + hlist_for_each_entry_safe_rcu(mn, n, t,
> + &mm->mmu_notifier.head, hlist) {
> + if (mn->ops->release)
> + mn->ops->release(mn, mm);
> + hlist_del(&mn->hlist);

This is a use-after-free issue. The hlist_del_rcu needs to be done before
the callout as the structure containing the mmu_notifier structure will
need to be freed from within the ->release callout.

Thanks,
Robin
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