[PATCH] efi_loader: fix memory leak in efi_var_collect

[Ilias Apalodimas]

Barebox has now ported some of the UEFI code. In the process
they found some bugs.

In this case when the variable buffer is too small, efi_var_collect()
returns EFI_BUFFER_TOO_SMALL but doesn't free the allocated 'buf'.

Fixes: 5f7dcf079de8c ("efi_loader: UEFI variable persistence")
Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
 lib/efi_loader/efi_var_common.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index d63c2d1b1cd8..e51b21fe0b0d 100644
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -446,8 +446,10 @@ efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *
 		efi_status_t ret;
 
 		if ((uintptr_t)buf + len <=
-		    (uintptr_t)var->name + old_var_name_length)
+		    (uintptr_t)var->name + old_var_name_length) {
+			free(buf);
 			return EFI_BUFFER_TOO_SMALL;
+		}
 
 		var_name_length = (uintptr_t)buf + len - (uintptr_t)var->name;
 		memcpy(var->name, old_var->name, old_var_name_length);
-- 
2.43.0