grub2/0395-powerpc-ieee1275-Enter-lockdown-based-on-ibm-secure-.patch
Nicolas Frayer 17ffd9b3e0 powerpc: Add appended signature feature
Resolves: #RHEL-24510
Signed-off-by: Nicolas Frayer <nfrayer@redhat.com>
2025-11-27 14:40:11 +01:00

123 lines
3.8 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Date: Mon, 6 Oct 2025 12:54:54 +0530
Subject: [PATCH] powerpc/ieee1275: Enter lockdown based on /ibm, secure-boot
Read secure boot mode from 'ibm,secure-boot' property and if the secure boot
mode is set to 2 (enforce), enter lockdown. Else it is considered as disabled.
There are three secure boot modes. They are
0 - disabled
No signature verification is performed. This is the default.
1 - audit
Signature verification is performed and if signature verification fails,
display the errors and allow the boot to continue.
2 - enforce
Lockdown the GRUB. Signature verification is performed and if signature
verification fails, display the errors and stop the boot.
Now, only support disabled and enforce.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
grub-core/kern/ieee1275/init.c | 56 +++++++++++++++++++++++++++++++-----------
1 file changed, 42 insertions(+), 14 deletions(-)
diff --git a/grub-core/kern/ieee1275/init.c b/grub-core/kern/ieee1275/init.c
index 482cad2..0c587d3 100644
--- a/grub-core/kern/ieee1275/init.c
+++ b/grub-core/kern/ieee1275/init.c
@@ -49,7 +49,14 @@
#if defined(__powerpc__) || defined(__i386__)
#include <grub/ieee1275/alloc.h>
#endif
+#if defined(__powerpc__)
#include <grub/lockdown.h>
+#endif
+
+#ifdef __powerpc__
+#define GRUB_SB_DISABLED ((grub_uint32_t) 0)
+#define GRUB_SB_ENFORCE ((grub_uint32_t) 2)
+#endif
/* The maximum heap size we're going to claim. Not used by sparc. */
#ifdef __i386__
@@ -1009,30 +1016,49 @@ grub_parse_cmdline (void)
}
}
+#ifdef __powerpc__
static void
-grub_get_ieee1275_secure_boot (void)
+grub_ieee1275_get_secure_boot (void)
{
grub_ieee1275_phandle_t root;
- int rc;
- grub_uint32_t is_sb;
+ grub_uint32_t sb_mode = GRUB_SB_DISABLED;
+ grub_int32_t rc;
- grub_ieee1275_finddevice ("/", &root);
+ rc = grub_ieee1275_finddevice ("/", &root);
+ if (rc != 0)
+ {
+ grub_error (GRUB_ERR_UNKNOWN_DEVICE, "couldn't find / node");
+ return;
+ }
- rc = grub_ieee1275_get_integer_property (root, "ibm,secure-boot", &is_sb,
- sizeof (is_sb), 0);
-
- /* ibm,secure-boot:
+ rc = grub_ieee1275_get_integer_property (root, "ibm,secure-boot", &sb_mode, sizeof (sb_mode), 0);
+ if (rc != 0)
+ {
+ grub_error (GRUB_ERR_UNKNOWN_DEVICE, "couldn't examine /ibm,secure-boot property");
+ return;
+ }
+ /*
+ * Secure Boot Mode:
* 0 - disabled
+ * No signature verification is performed. This is the default.
* 1 - audit
+ * Signature verification is performed and if signature verification
+ * fails, display the errors and allow the boot to continue.
* 2 - enforce
- * 3 - enforce + OS-specific behaviour
+ * Lockdown the GRUB. Signature verification is performed and If
+ * signature verification fails, display the errors and stop the boot.
*
- * We only support enforce.
+ * Now, only support disabled and enforce.
*/
- if (rc >= 0 && is_sb >= 2)
- grub_lockdown ();
+ if (sb_mode == GRUB_SB_ENFORCE)
+ {
+ grub_dprintf ("ieee1275", "Secure Boot Enabled\n");
+ grub_lockdown ();
+ }
+ else
+ grub_dprintf ("ieee1275", "Secure Boot Disabled\n");
}
-
+#endif /* __powerpc__ */
grub_addr_t grub_modbase;
void
@@ -1059,7 +1085,9 @@ grub_machine_init (void)
grub_install_get_time_ms (grub_rtc_get_time_ms);
#endif
- grub_get_ieee1275_secure_boot ();
+#ifdef __powerpc__
+ grub_ieee1275_get_secure_boot ();
+#endif
}
void