[U-Boot] [PATCH] efi_loader: variable: attributes may not be changed if a variable exists

[Heinrich Schuchardt]

On 5/15/19 8:09 AM, AKASHI Takahiro wrote:
> On Tue, May 14, 2019 at 08:08:49PM +0200, Heinrich Schuchardt wrote:
>> On 5/14/19 8:35 AM, Heinrich Schuchardt wrote:
>>> On 5/14/19 6:57 AM, AKASHI Takahiro wrote:
>>>> If a variable already exists, efi_set_variable() should not change
>>>> the variable's attributes. This patch enforces it.
>>>
>>> This behavior is mandated by UEFI spec 2.7.
>>>
>>> Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
>>
>> This patch let's `bootefi selftest`fail:
>>
>> Executing 'variables'
>> lib/efi_selftest/efi_selftest_variables.c(60):
>> TODO: QueryVariableInfo failed
>> lib/efi_selftest/efi_selftest_variables.c(119):
>> ERROR: SetVariable failed
>> lib/efi_selftest/efi_selftest.c(110):
>> ERROR: Executing 'variables' failed
>>
>> The preferred solution would be to implement APPEND_WRITE.
>>
>> Otherwise at least adjust the unit test concerning APPEND_WRITE to use
>> efi_st_todo() and not to abort the test.
>
> Since the current code doesn't supoort APPEND_WRITE, my commit
> doesn't break anything. You should fix selftest first.
>
> I don't have an immediate plan to implement APPEND_WRITE for now.
>
> -Takahiro Akashi
>
>> I suggest that you always run `bootefi selftest` before submitting
>> changes to the UEFI sub-system.
>>
>> Best regards
>>
>> Heinrich
>>
>>>
>>>>
>>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
>>>> ---
>>>>   lib/efi_loader/efi_variable.c | 9 +++++++++
>>>>   1 file changed, 9 insertions(+)
>>>>
>>>> diff --git a/lib/efi_loader/efi_variable.c
>>>> b/lib/efi_loader/efi_variable.c
>>>> index 37728c3c165d..c4f3a5d2743d 100644
>>>> --- a/lib/efi_loader/efi_variable.c
>>>> +++ b/lib/efi_loader/efi_variable.c
>>>> @@ -450,6 +450,15 @@ efi_status_t EFIAPI efi_set_variable(u16
>>>> *variable_name,
>>>>               ret = EFI_WRITE_PROTECTED;
>>>>               goto out;
>>>>           }
>>>> +
>>>> +        /*
>>>> +         * attributes won't be changed
>>>> +         * TODO: take care of APPEND_WRITE once supported
>>>> +         */
>>>> +        if (attr != attributes) {
>>>> +            ret = EFI_INVALID_PARAMETER;
>>>> +            goto out;

You are freeing val. But this value was not allocated by you.

I saw this with `bootefi selftest` after applying

diff --git a/lib/efi_selftest/efi_selftest_variables.c
b/lib/efi_selftest/efi_selftest_variables.c
index b028c64bbc..e8346d0d4a 100644
--- a/lib/efi_selftest/efi_selftest_variables.c
+++ b/lib/efi_selftest/efi_selftest_variables.c
@@ -115,10 +115,8 @@ static int execute(void)
                                    EFI_VARIABLE_BOOTSERVICE_ACCESS |
                                    EFI_VARIABLE_APPEND_WRITE,
                                    7, v + 8);
-       if (ret != EFI_SUCCESS) {
-               efi_st_error("SetVariable failed\n");
-               return EFI_ST_FAILURE;
-       }
+       if (ret != EFI_SUCCESS)
+               efi_st_todo("SetVariable: append failed\n");
        len = EFI_ST_MAX_DATA_SIZE;
        ret = runtime->get_variable(L"efi_st_var1", &guid_vendor1,
                                    &attr, &len, data);

Please, run (and if necessary adjust) unit tests before submitting patches.

Best regards

Heinrich

>>>> +        }
>>>>       }
>>>>
>>>>       val = malloc(2 * data_size + strlen("{ro,run,boot}(blob)") + 1);
>>>>
>>>
>>>
>>
>