Now that the infrastructure is in place to verify and sign initramfs
images, let's refuse them if the signature is invalid. Additionally, a
command-line option `initrdsig=[enforcing|checking]` is provided to
switch between failing to boot or reporting signature failures.
Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
---
init/initramfs.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/init/initramfs.c b/init/initramfs.c
index d2d2c68016c2..bb42ba6c0730 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -573,6 +573,20 @@ static int __init initramfs_async_setup(char *str)
}
__setup("initramfs_async=", initramfs_async_setup);
+static bool __initdata enforce_initrd_sig = IS_ENABLED(CONFIG_INITRAMFS_SIG);
+#ifdef CONFIG_INITRAMFS_SIG
+static int __init initrd_sig_setup(char *str)
+{
+ if (!strcmp(str, "enforcing"))
+ enforce_initrd_sig = true;
+ else if (!strcmp(str, "checking"))
+ enforce_initrd_sig = false;
+ return 1;
+}
+__setup("initrdsig=", initrd_sig_setup);
+#endif
+
+
extern char __initramfs_start[];
extern unsigned long __initramfs_size;
#include <linux/initrd.h>
@@ -766,7 +780,10 @@ static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
else
printk(KERN_INFO "Unpacking initramfs...\n");
- initrd_signature_check(&initrd_len);
+ if (initrd_signature_check(&initrd_len) && enforce_initrd_sig) {
+ printk(KERN_EMERG "Initramfs signature required\n");
+ goto done;
+ }
err = unpack_to_rootfs((char *)initrd_start, initrd_len);
if (err) {
--
2.46.0
