[PATCH v5 6/6] KVM: arm64: Ensure FFA ranges are page aligned

[Mostafa Saleh]

At the moment we only check that the size of the range is page
aligned, and truncate the address to the page boundary.
This make an assumption that TZ will do the same.

Harden this check by also checking that the base address is aligned
and reject it otherwise.

Signed-off-by: Mostafa Saleh <smostafa at google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 79de358333e4..ea39e3362efe 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -352,7 +352,7 @@ static u32 __ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges,
 		u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE;
 		u64 pfn = hyp_phys_to_pfn(range->address);
 
-		if (!PAGE_ALIGNED(sz))
+		if (!PAGE_ALIGNED(sz | range->address))
 			break;
 
 		if (__pkvm_host_share_ffa(pfn, sz / PAGE_SIZE))
@@ -372,7 +372,7 @@ static u32 __ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
 		u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE;
 		u64 pfn = hyp_phys_to_pfn(range->address);
 
-		if (!PAGE_ALIGNED(sz))
+		if (!PAGE_ALIGNED(sz | range->address))
 			break;
 
 		if (__pkvm_host_unshare_ffa(pfn, sz / PAGE_SIZE))
-- 
2.54.0.746.g67dd491aae-goog