ima: support for kexec image and initramfs
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.
Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig
Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes. Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.
Option 1: duplicate kernel_read_file enumeration in ima_hooks
enum kernel_read_file_id {
...
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
enum ima_hooks {
...
KEXEC_KERNEL_CHECK
KEXEC_INITRAMFS_CHECK
Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
FILE_CHECK = READING_MAX_ID,
MMAP_CHECK,
In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.
struct caller_id {
union {
enum ima_hooks func_id;
enum kernel_read_file_id read_id;
};
};
Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.
For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.
Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 7571ce8..646134c 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -612,6 +612,12 @@
entry->func = MMAP_CHECK;
else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
entry->func = BPRM_CHECK;
+ else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") ==
+ 0)
+ entry->func = KEXEC_KERNEL_CHECK;
+ else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK")
+ == 0)
+ entry->func = KEXEC_INITRAMFS_CHECK;
else
result = -EINVAL;
if (!result)
@@ -855,7 +861,8 @@
enum {
func_file = 0, func_mmap, func_bprm,
- func_module, func_firmware, func_post
+ func_module, func_firmware, func_post,
+ func_kexec_kernel, func_kexec_initramfs
};
static char *func_tokens[] = {
@@ -864,6 +871,8 @@
"BPRM_CHECK",
"MODULE_CHECK",
"FIRMWARE_CHECK",
+ "KEXEC_KERNEL_CHECK",
+ "KEXEC_INITRAMFS_CHECK",
"POST_SETATTR"
};
@@ -929,6 +938,12 @@
case POST_SETATTR:
seq_printf(m, pt(Opt_func), ft(func_post));
break;
+ case KEXEC_KERNEL_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_kexec_kernel));
+ break;
+ case KEXEC_INITRAMFS_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_kexec_initramfs));
+ break;
default:
snprintf(tbuf, sizeof(tbuf), "%d", func);
seq_printf(m, pt(Opt_func), tbuf);