[PATCH] lockdown: s390: kexec_file: don't skip signature verification when not secure IPLed

From: Coiby Xu
Date: Mon Nov 21 2022 - 02:29:08 EST


Currently for s390, lockdown doesn't prevent unsigned kernel image from
being kexec'ed when secure IPL is disabled. Fix it by always verifying
the signature regardless secure IPL is enabled or not.

Fixes: 155bdd30af17 ("kexec_file: Restrict at runtime if the kernel is locked down")

Cc: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
Cc: Jiri Bohac <jbohac@xxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Philipp Rudo <prudo@xxxxxxxxxx>
Cc: kexec@xxxxxxxxxxxxxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Signed-off-by: Coiby Xu <coxu@xxxxxxxxxx>
---
arch/s390/kernel/machine_kexec_file.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index fc6d5f58debe..627685426ac2 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -33,10 +33,6 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len)
unsigned long sig_len;
int ret;

- /* Skip signature verification when not secure IPLed. */
- if (!ipl_secure_flag)
- return 0;
-
if (marker_len > kernel_len)
return -EKEYREJECTED;

--
2.38.1