From 0443f768f0184ca7905d39f46a7fb0f40471bf42 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 2 Aug 2021 13:38:30 +0100 Subject: [PATCH] KVM: arm64: Unregister HYP sections from kmemleak in protected mode commit 47e6223c841e029bfc23c3ce594dac5525cebaf8 upstream. Booting a KVM host in protected mode with kmemleak quickly results in a pretty bad crash, as kmemleak doesn't know that the HYP sections have been taken away. This is specially true for the BSS section, which is part of the kernel BSS section and registered at boot time by kmemleak itself. Unregister the HYP part of the BSS before making that section HYP-private. The rest of the HYP-specific data is obtained via the page allocator or lives in other sections, none of which is subjected to kmemleak. Fixes: 90134ac9cabb ("KVM: arm64: Protect the .hyp sections from the host") Reviewed-by: Quentin Perret Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org # 5.13 Link: https://lore.kernel.org/r/20210802123830.2195174-3-maz@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kvm/arm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index facf4d41d32a2..3ed09e7f81f03 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -1957,6 +1958,12 @@ static int finalize_hyp_mode(void) if (ret) return ret; + /* + * Exclude HYP BSS from kmemleak so that it doesn't get peeked + * at, which would end badly once the section is inaccessible. + * None of other sections should ever be introspected. + */ + kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); ret = pkvm_mark_hyp_section(__hyp_bss); if (ret) return ret;