KVM: arm64: Inject SIGSEGV on illegal accesses

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The pKVM hypervisor will currently panic if the host tries to access
memory that it doesn't own (e.g. protected guest memory). Sadly, as
guest memory can still be mapped into the VMM's address space, userspace
can trivially crash the kernel/hypervisor by poking into guest memory.

To prevent this, inject the abort back in the host with S1PTW set in the
ESR, hence allowing the host to differentiate this abort from normal
userspace faults and inject a SIGSEGV cleanly.

Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-20-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>

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Quentin Perret 2026-03-30 15:48:20 +01:00 • committed by Marc Zyngier

parent be9ed3529e

commit 9ff714a092

2 changed files with 59 additions and 0 deletions

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37

arch/arm64/kvm/hyp/nvhe/mem_protect.c

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22

arch/arm64/mm/fault.c

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