efi: fix panic in kdump kernel
Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.
Tested with QEMU and OVMF firmware.
Fixes: bad267f9e18f ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 8859fb0..fdf07dd 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -203,6 +203,8 @@ static bool generic_ops_supported(void)
name_size = sizeof(name);
+ if (!efi.get_next_variable)
+ return false;
status = efi.get_next_variable(&name_size, &name, &guid);
if (status == EFI_UNSUPPORTED)
return false;
