[PATCH] [RFC] lib: efi_loader: don't delete invalid handles

[Etienne Carriere]

Changes efi_delete_handle() to not free EFI handles that are not related
to EFI objects.

This change tries to resolved an issue seen since U-Boot v2022.07
in which EFI ExitBootService  attempts to release some EFI handles twice.

The issue was seen booting a EFI shell that invokes 'connect -r' and
then boots a Linux kernel. Execution of connect command makes EFI
subsystem to bind a block device for each root block devices EFI handles.
However these EFI device handles are already bound to a driver and we
can have 2 registered devices relating to the same EFI handler. On
ExitBootService, the loop removing the devices makes these EFI handles
to be released twice which corrupts memory.

This patch prevents the memory release operation caused by the issue but
I don't think this patch is the right way to addresse the problem. Any
help will be much appreciated.

Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
---
 lib/efi_loader/efi_boottime.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 4da64b5d29..e38990ace2 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -619,9 +619,15 @@ efi_status_t efi_remove_all_protocols(const efi_handle_t handle)
  */
 void efi_delete_handle(efi_handle_t handle)
 {
+	efi_status_t ret;
+
 	if (!handle)
 		return;
-	efi_remove_all_protocols(handle);
+
+	ret = efi_remove_all_protocols(handle);
+	if (ret == EFI_INVALID_PARAMETER)
+		return;
+
 	list_del(&handle->link);
 	free(handle);
 }
-- 
2.25.1