efi_loader: LocateDevicePath() incorrect parameter check

A parameter check in LocateDevicePath() does not match the requirements of
the UEFI spec.

If device is NULL, only return EFI_INVALID_PARAMETER if a matching handle
is found.

Cf. UEFI SCT II specification (2017)3.3.7 LocateDevicePath(), 5.1.3.7.3

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 887baaab02640dce95da855d697776de75455721..50c5374e5fb4b9236e743e58a3ca1008495e3f9a 100644 (file)
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -2261,7 +2261,7 @@ static efi_status_t EFIAPI efi_locate_device_path(
 
        EFI_ENTRY("%pUl, %p, %p", protocol, device_path, device);
 
-       if (!protocol || !device_path || !*device_path || !device) {
+       if (!protocol || !device_path || !*device_path) {
                ret = EFI_INVALID_PARAMETER;
                goto out;
        }
@@ -2294,6 +2294,10 @@ static efi_status_t EFIAPI efi_locate_device_path(
                /* Check if dp is a subpath of device_path */
                if (memcmp(*device_path, dp, len_dp))
                        continue;
+               if (!device) {
+                       ret = EFI_INVALID_PARAMETER;
+                       goto out;
+               }
                *device = handles[i];
                len_best = len_dp;
        }