[lvc-project] [PATCH 1/2] arm64: KVM: prevent overflow in inject_abt64

[Anastasia Belova]

ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT = 0x20 << 26.
ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT = 0x21 << 26.
There operations' results are int with 1 in 32th bit.
While casting these values into u64 (esr is u64) 1
fills 32 highest bits.

Add explicit casting to prevent it.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: aa8eff9bfbd5 ("arm64: KVM: fault injection into a guest")
Signed-off-by: Anastasia Belova <abelova at astralinux.ru>
---
 arch/arm64/kvm/inject_fault.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index a640e839848e..b6b2cfff6629 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -74,9 +74,9 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr
 	 * an AArch32 fault, it means we managed to trap an EL0 fault.
 	 */
 	if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t)
-		esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT);
+		esr |= ((u64)ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT);
 	else
-		esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);
+		esr |= ((u64)ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);
 
 	if (!is_iabt)
 		esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT;
-- 
2.30.2