Received-SPF: pass (google.com: domain of linux-kernel+bounces-110838-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Date: Fri, 22 Mar 2024 01:08:45 +0000
Precedence: bulk
Mime-Version: 1.0
Message-ID: <20240322010846.305860-1-ovt@google.com>
Subject: [PATCH] efi: fix panic in kdump kernel
From: Oleksandr Tymoshenko <ovt@google.com>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: ovt@google.com, johan+linaro@kernel.org, linux-efi@vger.kernel.org, 
	linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"

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.

Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
---
 drivers/firmware/efi/efi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 8859fb0b006d..800b85807a02 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 == NULL)
+		return false;
 	status = efi.get_next_variable(&name_size, &name, &guid);
 	if (status == EFI_UNSUPPORTED)
 		return false;
-- 
2.44.0.396.g6e790dbe36-goog