ima: Support platform keyring for kernel appraisal
On secure boot enabled systems, the bootloader verifies the kernel
image and possibly the initramfs signatures based on a set of keys. A
soft reboot(kexec) of the system, with the same kernel image and
initramfs, requires access to the original keys to verify the
signatures.
This patch allows IMA-appraisal access to those original keys, now
loaded on the platform keyring, needed for verifying the kernel image
and initramfs signatures.
[zohar@linux.ibm.com: only use platform keyring if it's enabled (Thiago)]
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index deec180..f6ac405 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -289,12 +289,22 @@
case EVM_IMA_XATTR_DIGSIG:
set_bit(IMA_DIGSIG, &iint->atomic_flags);
rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
- (const char *)xattr_value, rc,
+ (const char *)xattr_value,
+ xattr_len,
iint->ima_hash->digest,
iint->ima_hash->length);
if (rc == -EOPNOTSUPP) {
status = INTEGRITY_UNKNOWN;
- } else if (rc) {
+ break;
+ }
+ if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
+ func == KEXEC_KERNEL_CHECK)
+ rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM,
+ (const char *)xattr_value,
+ xattr_len,
+ iint->ima_hash->digest,
+ iint->ima_hash->length);
+ if (rc) {
cause = "invalid-signature";
status = INTEGRITY_FAIL;
} else {
