KVM: arm64: ptdump: Check the page tables aren't freed when accessing

An open debugfs file keeps the KVM structure alive, but does not prevent
mmu notifier release from freeing the stage-2 page tables when the VMM’s
address space is torn down. Therefore page tables belonging to the mmus
could have been freed when a thread opens or reads the ptdump files.
Take the mmu_lock and check mmu->pgt is still alive before accessing the
page tables.

Also for the ipa_range file and stage2_levels file, switch from keeping
the pointer to the page tables to keeping the pointer to the mmu.

Fixes: 7c4f73548ed1 ("KVM: arm64: Register ptdump with debugfs on guest creation")
Reported-by: Sashiko AI <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/kvmarm/20260623144054.B91D21F000E9@smtp.kernel.org/
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Itaru Kitayama <itaru.kitayama@fujitsu.com>
Signed-off-by: Wei-Lin Chang <weilin.chang@arm.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260924094951.727352-2-weilin.chang@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

0 files changed, 0 insertions, 0 deletions