[PATCH] efi_loader: Extra checks while opening an OPTEE session

[Heinrich Schuchardt]

Am 23. Dezember 2020 11:43:19 MEZ schrieb Ilias Apalodimas <ilias.apalodimas at linaro.org>:
>When opening an OP-TEE session we need to check the internal return
>value of OP-TEE call arguments as well the return code of the
>function itself.
>The code was also ignoring to close the OP-TEE session in case the
>shared memory registration failed.
>
>Fixes: f042e47e8fb43 ("efi_loader: Implement EFI variable handling via
>OP-TEE")
>Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
>---
> lib/efi_loader/efi_variable_tee.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
>diff --git a/lib/efi_loader/efi_variable_tee.c
>b/lib/efi_loader/efi_variable_tee.c
>index be6f3dfad469..717d0b45e7cd 100644
>--- a/lib/efi_loader/efi_variable_tee.c
>+++ b/lib/efi_loader/efi_variable_tee.c
>@@ -45,10 +45,11 @@ static int get_connection(struct mm_connection
>*conn)
> 	memset(&arg, 0, sizeof(arg));
> 	tee_optee_ta_uuid_to_octets(arg.uuid, &uuid);
> 	rc = tee_open_session(tee, &arg, 0, NULL);
>-	if (!rc) {
>-		conn->tee = tee;
>-		conn->session = arg.session;
>-	}
>+	if (rc || arg.ret != TEE_SUCCESS)
>+		return rc == 0 ? -EIO : rc;

 Could you simplify this, please

if (rc)
     return rc;
if (arg.ret != TEE_SUCCESS)
    return -EIO;

>+
>+	conn->tee = tee;
>+	conn->session = arg.session;
> 
> 	return rc;

return 0;

Best regards

Heinrich

> }
>@@ -88,6 +89,7 @@ static efi_status_t optee_mm_communicate(void
>*comm_buf, ulong dsize)
> 
> 	if (tee_shm_register(conn.tee, comm_buf, buf_size, 0, &shm)) {
> 		log_err("Unable to register shared memory\n");
>+		tee_close_session(conn.tee, conn.session);
> 		return EFI_UNSUPPORTED;
> 	}
>