efi: fix memory leak in krealloc failure handling

In the previous code, there was a memory leak issue where the
previously allocated memory was not freed upon a failed krealloc
operation. This patch addresses the problem by releasing the old memory
before setting the pointer to NULL in case of a krealloc failure. This
ensures that memory is properly managed and avoids potential memory
leaks.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 1599f11768426d8ff72c9c2cfc9387728af2efa3..9cfac61812f68781758e85d36eca224f718d2a41 100644 (file)
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -273,9 +273,13 @@ static __init int efivar_ssdt_load(void)
                if (status == EFI_NOT_FOUND) {
                        break;
                } else if (status == EFI_BUFFER_TOO_SMALL) {
-                       name = krealloc(name, name_size, GFP_KERNEL);
-                       if (!name)
+                       efi_char16_t *name_tmp =
+                               krealloc(name, name_size, GFP_KERNEL);
+                       if (!name_tmp) {
+                               kfree(name);
                                return -ENOMEM;
+                       }
+                       name = name_tmp;
                        continue;
                }