diff options
| -rw-r--r-- | shim.c | 29 |
1 files changed, 19 insertions, 10 deletions
@@ -1472,18 +1472,27 @@ load_certs(EFI_HANDLE image_handle) UINTN old = buffersize; efi_status = dir->Read(dir, &buffersize, buffer); if (efi_status == EFI_BUFFER_TOO_SMALL) { - if (buffersize != old) { - buffer = ReallocatePool(buffer, old, buffersize); - if (buffer == NULL) { - perror(L"Failed to read directory %s - %r\n", - PathName, EFI_OUT_OF_RESOURCES); + if (buffersize == old) { + /* + * Some UEFI drivers or firmwares are not compliant with + * the EFI_FILE_PROTOCOL.Read() specs and do not return the + * required buffer size along with EFI_BUFFER_TOO_SMALL. + * Work around this by progressively increasing the buffer + * size, up to a certain point, until the call succeeds. + */ + perror(L"Error reading directory %s - non-compliant UEFI driver or firmware!\n", + PathName); + buffersize = (buffersize < 4) ? 4 : buffersize * 2; + if (buffersize > 1024) goto done; - } - continue; } - perror(L"Failed to read directory %s - buggy firmware\n", - PathName); - goto done; + buffer = ReallocatePool(buffer, old, buffersize); + if (buffer == NULL) { + perror(L"Failed to read directory %s - %r\n", + PathName, EFI_OUT_OF_RESOURCES); + goto done; + } + continue; } else if (EFI_ERROR(efi_status)) { perror(L"Failed to read directory %s - %r\n", PathName, efi_status); |