diff options
| author | Sean Christopherson <seanjc@google.com> | 2025-11-10 13:24:53 -0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-11-13 08:30:07 -0800 |
| commit | 398180f93cf3c7bb0ee3f512b139ad01843f3ddf (patch) | |
| tree | b611205efc331f1978b4b5c12923bb571e4ab236 | |
| parent | 11b79f8318aefc7ddfd12668fd1d80bde1c9f7bc (diff) | |
KVM: TDX: Use struct_size to simplify tdx_get_capabilities()
Use struct_size() instead of manually calculating the number of bytes to
allocate for 'caps', including the nested flexible array, and copy all of
'caps' to user space with a single copy_to_user() call (thanks to the full
size being provided by struct_size()).
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://patch.msgid.link/20251017213914.167301-1-thorsten.blum@linux.dev
[sean: separate from swap of get_user() vs. kzalloc() ordering]
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/vmx/tdx.c | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index cc751c088476..a940a54ca593 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -2231,9 +2231,8 @@ static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) if (nr_user_entries < td_conf->num_cpuid_config) return -E2BIG; - caps = kzalloc(sizeof(*caps) + - sizeof(struct kvm_cpuid_entry2) * td_conf->num_cpuid_config, - GFP_KERNEL); + caps = kzalloc(struct_size(caps, cpuid.entries, + td_conf->num_cpuid_config), GFP_KERNEL); if (!caps) return -ENOMEM; @@ -2241,16 +2240,12 @@ static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) if (ret) goto out; - if (copy_to_user(user_caps, caps, sizeof(*caps))) { + if (copy_to_user(user_caps, caps, struct_size(caps, cpuid.entries, + caps->cpuid.nent))) { ret = -EFAULT; goto out; } - if (copy_to_user(user_caps->cpuid.entries, caps->cpuid.entries, - caps->cpuid.nent * - sizeof(caps->cpuid.entries[0]))) - ret = -EFAULT; - out: /* kfree() accepts NULL. */ kfree(caps); |