Return -EFAULT if copy_to_user() fails; if accessing user memory faults, copy_to_user() returns the number of bytes remaining, not an error code. Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Steve Rutherford <srutherford@xxxxxxxxxx> Cc: Brijesh Singh <brijesh.singh@xxxxxxx> Cc: Ashish Kalra <ashish.kalra@xxxxxxx> Fixes: d3d1af85e2c7 ("KVM: SVM: Add KVM_SEND_UPDATE_DATA command") Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- arch/x86/kvm/svm/sev.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index a9d8d6aafdb8..1f99c240db6d 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1303,8 +1303,9 @@ static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) } /* Copy packet header to userspace. */ - ret = copy_to_user((void __user *)(uintptr_t)params.hdr_uaddr, hdr, - params.hdr_len); + if (copy_to_user((void __user *)(uintptr_t)params.hdr_uaddr, hdr, + params.hdr_len)) + ret = -EFAULT; e_free_trans_data: kfree(trans_data); -- 2.31.1.607.g51e8a6a459-goog