Peter Jones
4816cd7533
lib: find_in_variable_esl(): Fix a tiny nitpick clang-analyze has.
...
clang-analyze believes the following:
311 EFI_STATUS
312 variable_enroll_hash(CHAR16 *var, EFI_GUID owner,
313 UINT8 hash[SHA256_DIGEST_SIZE])
314 {
315 EFI_STATUS efi_status;
316
317 efi_status = find_in_variable_esl(var, owner, hash, SHA256_DIGEST_SIZE);
> Calling 'find_in_variable_esl' →
260 EFI_STATUS
261 find_in_variable_esl(CHAR16* var, EFI_GUID owner, UINT8 *key, UINTN keylen)
262 {
263 UINTN DataSize;
264 UINT8 *Data;
> ← 'Data' declared without an initial value →
265 EFI_STATUS efi_status;
266
267 efi_status = get_variable(var, &Data, &DataSize, owner);
> ← Calling 'get_variable' →
237 EFI_STATUS
238 get_variable(CHAR16 *var, UINT8 **data, UINTN *len, EFI_GUID owner)
239 {
240 return get_variable_attr(var, data, len, owner, NULL);
> ← Calling 'get_variable_attr' →
213 EFI_STATUS
214 get_variable_attr(CHAR16 *var, UINT8 **data, UINTN *len, EFI_GUID owner,
215 UINT32 *attributes)
216 {
217 EFI_STATUS efi_status;
218
219 *len = 0;
220
221 efi_status = GetVariable(var, &owner, NULL, len, NULL);
> ← Calling 'GetVariable' →
> ← Returning from 'GetVariable' →
222 if (efi_status != EFI_BUFFER_TOO_SMALL)
> ← Assuming the condition is true →
> ← Taking true branch →
223 return efi_status;
224
225 *data = AllocateZeroPool(*len);
226 if (!*data)
227 return EFI_OUT_OF_RESOURCES;
228
229 efi_status = GetVariable(var, &owner, attributes, len, *data);
230 if (EFI_ERROR(efi_status)) {
231 FreePool(*data);
232 *data = NULL;
233 }
234 return efi_status;
235 }
And it can't figure out that the first GetVariable() call will, in fact,
always return EFI_BUFFER_TOO_SMALL, and that AllocateZeroPool() will
then *correctly* clobber the two variables we never assigned the value
from. It also then believes that efi_status might have been returned
/without/ being an error, and thinks that means we'll use the
uninitialized pointer.
This won't happen, but hey, let's make the code better express to the
checker what is intended.
Signed-off-by: Peter Jones <pjones@redhat.com>
2018-03-12 16:21:43 -04:00
