From: Oleksandr Tymoshenko <ovt@google.com>
Date: Sat, 23 Mar 2024 06:33:33 +0000 (+0000)
Subject: efi: fix panic in kdump kernel
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=62b71cd73d41ddac6b1760402bbe8c4932e23531;p=people%2Faperard%2Flinux.git

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 8859fb0b006d3..fdf07dd6f4591 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;