From 871c433bae565306cfc3a1a386bf7328bc9d31cb Mon Sep 17 00:00:00 2001 From: Rustam Kovhaev Date: Fri, 18 Sep 2020 05:05:00 -0700 Subject: [PATCH] KVM: use struct_size() and flex_array_size() helpers in kvm_io_bus_unregister_dev() Make use of the struct_size() helper to avoid any potential type mistakes and protect against potential integer overflows Make use of the flex_array_size() helper to calculate the size of a flexible array member within an enclosing structure Suggested-by: Gustavo A. R. Silva Signed-off-by: Rustam Kovhaev Message-Id: <20200918120500.954436-1-rkovhaev@gmail.com> Reviewed-by: Gustavo A. R. Silva Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index cf88233b819a..68edd25dcb11 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4350,10 +4350,10 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1), GFP_KERNEL_ACCOUNT); if (new_bus) { - memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); + memcpy(new_bus, bus, struct_size(bus, range, i)); new_bus->dev_count--; memcpy(new_bus->range + i, bus->range + i + 1, - (new_bus->dev_count - i) * sizeof(struct kvm_io_range)); + flex_array_size(new_bus, range, new_bus->dev_count - i)); } else { pr_err("kvm: failed to shrink bus, removing it completely\n"); for (j = 0; j < bus->dev_count; j++) {