[PATCH 20/25] efi_loader: capsule: Add runtime capsule flags checks

[abdellatif.elkhlifi at arm.com]

From: Emekcan Aras <emekcan.aras at arm.com>

Add missing checks according to the UEFI specification [1]

checks added for these capsule flags:

CAPSULE_FLAGS_PERSIST_ACROSS_RESET
CAPSULE_FLAGS_POPULATE_SYSTEM_TABLE
CAPSULE_FLAGS_INITIATE_RESET

[1]: Table 8.8 Flag Firmware Behavior,
        https://uefi.org/specs/UEFI/2.10/08_Services_Runtime_Services.html

Signed-off-by: Emekcan Aras <emekcan.aras at arm.com>
Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
Cc: Tom Rini <trini at konsulko.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Adriano Cordova <adrianox at gmail.com>
Cc: Sughosh Ganu <sughosh.ganu at linaro.org>
---
 lib/efi_loader/efi_capsule.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
index 113cfe30fde..a5ebe4994dc 100644
--- a/lib/efi_loader/efi_capsule.c
+++ b/lib/efi_loader/efi_capsule.c
@@ -769,6 +769,36 @@ efi_status_t EFIAPI efi_update_capsule(
 			continue;
 		}
 
+		/*
+		 * ScatterGatherList must point to a list when the
+		 * CAPSULE_FLAGS_PERSIST_ACROSS_RESET flag is set.
+		 */
+		if ((capsule->flags & CAPSULE_FLAGS_PERSIST_ACROSS_RESET) &&
+		    !scatter_gather_list) {
+			ret = EFI_INVALID_PARAMETER;
+			goto out;
+		}
+
+		/*
+		 * The CAPSULE_FLAGS_PERSIST_ACROSS_RESET flag must be set
+		 * along with the CAPSULE_FLAGS_POPULATE_SYSTEM_TABLE flag.
+		 */
+		if ((capsule->flags & CAPSULE_FLAGS_POPULATE_SYSTEM_TABLE) &&
+		    !(capsule->flags & CAPSULE_FLAGS_PERSIST_ACROSS_RESET)) {
+			ret = EFI_INVALID_PARAMETER;
+			goto out;
+		}
+
+		/*
+		 * The CAPSULE_FLAGS_PERSIST_ACROSS_RESET flag must be set
+		 * along with the CAPSULE_FLAGS_INITIATE_RESET flag.
+		 */
+		if ((capsule->flags & CAPSULE_FLAGS_INITIATE_RESET) &&
+		    !(capsule->flags & CAPSULE_FLAGS_PERSIST_ACROSS_RESET)) {
+			ret = EFI_INVALID_PARAMETER;
+			goto out;
+		}
+
 		log_debug("Capsule[%d] (guid:%pUs)\n",
 			  i, &capsule->capsule_guid);
 		ret  = efi_capsule_update_firmware(capsule);
-- 
2.25.1