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authorMimi Zohar <zohar@linux.vnet.ibm.com>2016-01-14 20:59:14 -0500
committerMimi Zohar <zohar@linux.vnet.ibm.com>2016-02-21 09:06:16 -0500
commitd9ddf077bb85b54200dfcb5f2edec4f0d6a7c2ca (patch)
tree1319aaa27cd27007ef02c076056be5d0268ee666 /security
parentb804defe4297157a9ff45863769efe9a01953398 (diff)
downloadleg-kernel-d9ddf077bb85b54200dfcb5f2edec4f0d6a7c2ca.tar.gz
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>
Diffstat (limited to 'security')
-rw-r--r--security/integrity/ima/ima.h2
-rw-r--r--security/integrity/ima/ima_main.c15
-rw-r--r--security/integrity/ima/ima_policy.c17
3 files changed, 27 insertions, 7 deletions
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index a5d25921ee3c..bd97e0d290de 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -147,6 +147,8 @@ enum ima_hooks {
POST_SETATTR,
MODULE_CHECK,
FIRMWARE_CHECK,
+ KEXEC_KERNEL_CHECK,
+ KEXEC_INITRAMFS_CHECK,
MAX_CHECK
};
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 5da0b9c00072..f76488162c1e 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -339,6 +339,13 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
return 0;
}
+static int read_idmap[READING_MAX_ID] = {
+ [READING_FIRMWARE] = FIRMWARE_CHECK,
+ [READING_MODULE] = MODULE_CHECK,
+ [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
+ [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
+};
+
/**
* ima_post_read_file - in memory collect/appraise/audit measurement
* @file: pointer to the file to be measured/appraised/audit
@@ -355,7 +362,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id read_id)
{
- enum ima_hooks func = FILE_CHECK;
+ enum ima_hooks func;
if (!file && read_id == READING_FIRMWARE) {
if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
@@ -373,11 +380,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
return 0;
}
- if (read_id == READING_FIRMWARE)
- func = FIRMWARE_CHECK;
- else if (read_id == READING_MODULE)
- func = MODULE_CHECK;
-
+ func = read_idmap[read_id] ?: FILE_CHECK;
return process_measurement(file, buf, size, MAY_READ, func, 0);
}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 7571ce8841ff..646134cdf3e8 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -612,6 +612,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
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 @@ static char *mask_tokens[] = {
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 @@ static char *func_tokens[] = {
"BPRM_CHECK",
"MODULE_CHECK",
"FIRMWARE_CHECK",
+ "KEXEC_KERNEL_CHECK",
+ "KEXEC_INITRAMFS_CHECK",
"POST_SETATTR"
};
@@ -929,6 +938,12 @@ static void policy_func_show(struct seq_file *m, enum ima_hooks func)
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);