array_size() is used in alloc calls to compute the allocation size. Next, "raw" multiplication is used to compute the size for copy_from_user(). The patch removes duplicated computation by saving the size in a var. No security concerns, just a small optimization.
Signed-off-by: Denis Efremov <[email protected]> --- arch/x86/kvm/cpuid.c | 9 ++++----- virt/kvm/kvm_main.c | 8 ++++---- 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 901cd1fdecd9..3363b7531af1 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -184,14 +184,13 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, goto out; r = -ENOMEM; if (cpuid->nent) { - cpuid_entries = - vmalloc(array_size(sizeof(struct kvm_cpuid_entry), - cpuid->nent)); + const size_t size = array_size(sizeof(struct kvm_cpuid_entry), + cpuid->nent); + cpuid_entries = vmalloc(size); if (!cpuid_entries) goto out; r = -EFAULT; - if (copy_from_user(cpuid_entries, entries, - cpuid->nent * sizeof(struct kvm_cpuid_entry))) + if (copy_from_user(cpuid_entries, entries, size)) goto out; } for (i = 0; i < cpuid->nent; i++) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 731c1e517716..001e1929e01c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3722,15 +3722,15 @@ static long kvm_vm_ioctl(struct file *filp, if (routing.flags) goto out; if (routing.nr) { + const size_t size = array_size(sizeof(*entries), + routing.nr); r = -ENOMEM; - entries = vmalloc(array_size(sizeof(*entries), - routing.nr)); + entries = vmalloc(size); if (!entries) goto out; r = -EFAULT; urouting = argp; - if (copy_from_user(entries, urouting->entries, - routing.nr * sizeof(*entries))) + if (copy_from_user(entries, urouting->entries, size)) goto out_free_irq_routing; } r = kvm_set_irq_routing(kvm, entries, routing.nr, -- 2.26.2
