From 1713e5aa05fff3951e747548b373bd2c81be4e7a Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 16 Sep 2015 10:54:37 +0100 Subject: [PATCH] arm64: KVM: Fix user access for debug registers MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When setting the debug register from userspace, make sure that copy_from_user() is called with its parameters in the expected order. It otherwise doesn't do what you think. Fixes: 84e690bfbed1 ("KVM: arm64: introduce vcpu->arch.debug_ptr") Reported-by: Peter Maydell Cc: Alex Bennée Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index b41607d270ac..1d0463e6a9e3 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -272,7 +272,7 @@ static int set_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; } @@ -314,7 +314,7 @@ static int set_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; @@ -358,7 +358,7 @@ static int set_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; } @@ -400,7 +400,7 @@ static int set_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; } -- 2.20.1