From 69a598288195947a1662b53de702eb6976af96b7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 10 Aug 2026 18:06:16 +0100 Subject: [PATCH] KVM: arm64: Correctly cap TLBI Range to the architural limit TLB Invalidation by Range has a fairly powerful way of encoding pretty large ranges in a small number of bits. This range can be based on an arbitrary VA, which means it is pretty easy for a guest to generate an overflow should the hypervisor be naive enough to add the range to the base... Make sure the range is capped to the limit dictated by the address bit that determines the VA range. For an IPA invalidation, this is further corrected down the line to ignore the upper range. Fixes: 4ffa72ad8f37e ("KVM: arm64: nv: Add S1 TLB invalidation primitive for VNCR_EL2") Reported-by: Wei-Lin Chang Link: https://lore.kernel.org/r/yifz3wn5gk5sr6mapi32trgk5m5kp33bquctsjmkifebnsnndt@fix6u4rthx4g Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Reviewed-by: Wei-Lin Chang Link: https://patch.msgid.link/20260810170616.746100-1-maz@kernel.org Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_nested.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index c83be6d0e79a..1ed708335809 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -305,6 +305,12 @@ static inline u64 decode_range_tlbi(u64 val, u64 *range, u16 *asid) num = FIELD_GET(GENMASK(43, 39), val); *range = __TLBI_RANGE_PAGES(num, scale) << shift; + /* Cap the range to the correct half of the address space */ + if (!(base & BIT(48))) + *range = min(*range, (BIT(48) - base)); + else + *range = min(*range, ~base + 1); + return base; }