Re: [PATCH v2 17/33] mm: kfence: Disable KMSAN when checking the canary

2023-12-08 Thread Alexander Potapenko
On Fri, Dec 8, 2023 at 1:53 PM Alexander Potapenko wrote: > > On Tue, Nov 21, 2023 at 11:02 PM Ilya Leoshkevich wrote: > > > > KMSAN warns about check_canary() accessing the canary. > > > > The reason is that, even though set_canary() is properly instrumented > > and sets shadow, slub explicitly

Re: [PATCH v2 17/33] mm: kfence: Disable KMSAN when checking the canary

2023-12-08 Thread Alexander Potapenko
On Tue, Nov 21, 2023 at 11:02 PM Ilya Leoshkevich wrote: > > KMSAN warns about check_canary() accessing the canary. > > The reason is that, even though set_canary() is properly instrumented > and sets shadow, slub explicitly poisons the canary's address range > afterwards. > > Unpoisoning the

[PATCH v2 17/33] mm: kfence: Disable KMSAN when checking the canary

2023-11-21 Thread Ilya Leoshkevich
KMSAN warns about check_canary() accessing the canary. The reason is that, even though set_canary() is properly instrumented and sets shadow, slub explicitly poisons the canary's address range afterwards. Unpoisoning the canary is not the right thing to do: only check_canary() is supposed to