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authorLinus Torvalds <torvalds@linux-foundation.org>2016-03-17 11:33:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-17 11:33:45 -0700
commitbb7aeae3d680c2c777f54274b0270ced0599f33d (patch)
tree4801a103c2b157b5019cf38a19dc67d54bf38453 /security/integrity/ima/ima_main.c
parent70477371dc350746d10431d74f0f213a8d59924c (diff)
parent88a1b564a20e371e6be41b39b85673e9c1959491 (diff)
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Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris: "There are a bunch of fixes to the TPM, IMA, and Keys code, with minor fixes scattered across the subsystem. IMA now requires signed policy, and that policy is also now measured and appraised" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (67 commits) X.509: Make algo identifiers text instead of enum akcipher: Move the RSA DER encoding check to the crypto layer crypto: Add hash param to pkcs1pad sign-file: fix build with CMS support disabled MAINTAINERS: update tpmdd urls MODSIGN: linux/string.h should be #included to get memcpy() certs: Fix misaligned data in extra certificate list X.509: Handle midnight alternative notation in GeneralizedTime X.509: Support leap seconds Handle ISO 8601 leap seconds and encodings of midnight in mktime64() X.509: Fix leap year handling again PKCS#7: fix unitialized boolean 'want' firmware: change kernel read fail to dev_dbg() KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert KEYS: Reserve an extra certificate symbol for inserting without recompiling modsign: hide openssl output in silent builds tpm_tis: fix build warning with tpm_tis_resume ima: require signed IMA policy ima: measure and appraise the IMA policy itself ima: load policy using path ...
Diffstat (limited to 'security/integrity/ima/ima_main.c')
-rw-r--r--security/integrity/ima/ima_main.c92
1 files changed, 67 insertions, 25 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 9d96551d0196..391f41751021 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -24,7 +24,6 @@
#include <linux/slab.h>
#include <linux/xattr.h>
#include <linux/ima.h>
-#include <crypto/hash_info.h>
#include "ima.h"
@@ -154,8 +153,8 @@ void ima_file_free(struct file *file)
ima_check_last_writer(iint, inode, file);
}
-static int process_measurement(struct file *file, int mask, int function,
- int opened)
+static int process_measurement(struct file *file, char *buf, loff_t size,
+ int mask, enum ima_hooks func, int opened)
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint = NULL;
@@ -163,9 +162,10 @@ static int process_measurement(struct file *file, int mask, int function,
char *pathbuf = NULL;
const char *pathname = NULL;
int rc = -ENOMEM, action, must_appraise;
- struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL;
+ struct evm_ima_xattr_data *xattr_value = NULL;
int xattr_len = 0;
bool violation_check;
+ enum hash_algo hash_algo;
if (!ima_policy_flag || !S_ISREG(inode->i_mode))
return 0;
@@ -174,8 +174,8 @@ static int process_measurement(struct file *file, int mask, int function,
* bitmask based on the appraise/audit/measurement policy.
* Included is the appraise submask.
*/
- action = ima_get_action(inode, mask, function);
- violation_check = ((function == FILE_CHECK || function == MMAP_CHECK) &&
+ action = ima_get_action(inode, mask, func);
+ violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
if (!action && !violation_check)
return 0;
@@ -184,7 +184,7 @@ static int process_measurement(struct file *file, int mask, int function,
/* Is the appraise rule hook specific? */
if (action & IMA_FILE_APPRAISE)
- function = FILE_CHECK;
+ func = FILE_CHECK;
inode_lock(inode);
@@ -214,16 +214,19 @@ static int process_measurement(struct file *file, int mask, int function,
/* Nothing to do, just return existing appraised status */
if (!action) {
if (must_appraise)
- rc = ima_get_cache_status(iint, function);
+ rc = ima_get_cache_status(iint, func);
goto out_digsig;
}
template_desc = ima_template_desc_current();
if ((action & IMA_APPRAISE_SUBMASK) ||
strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
- xattr_ptr = &xattr_value;
+ /* read 'security.ima' */
+ xattr_len = ima_read_xattr(file->f_path.dentry, &xattr_value);
- rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len);
+ hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
+
+ rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
if (rc != 0) {
if (file->f_flags & O_DIRECT)
rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES;
@@ -237,7 +240,7 @@ static int process_measurement(struct file *file, int mask, int function,
ima_store_measurement(iint, file, pathname,
xattr_value, xattr_len);
if (action & IMA_APPRAISE_SUBMASK)
- rc = ima_appraise_measurement(function, iint, file, pathname,
+ rc = ima_appraise_measurement(func, iint, file, pathname,
xattr_value, xattr_len, opened);
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
@@ -270,7 +273,8 @@ out:
int ima_file_mmap(struct file *file, unsigned long prot)
{
if (file && (prot & PROT_EXEC))
- return process_measurement(file, MAY_EXEC, MMAP_CHECK, 0);
+ return process_measurement(file, NULL, 0, MAY_EXEC,
+ MMAP_CHECK, 0);
return 0;
}
@@ -289,7 +293,8 @@ int ima_file_mmap(struct file *file, unsigned long prot)
*/
int ima_bprm_check(struct linux_binprm *bprm)
{
- return process_measurement(bprm->file, MAY_EXEC, BPRM_CHECK, 0);
+ return process_measurement(bprm->file, NULL, 0, MAY_EXEC,
+ BPRM_CHECK, 0);
}
/**
@@ -304,24 +309,26 @@ int ima_bprm_check(struct linux_binprm *bprm)
*/
int ima_file_check(struct file *file, int mask, int opened)
{
- return process_measurement(file,
+ return process_measurement(file, NULL, 0,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
FILE_CHECK, opened);
}
EXPORT_SYMBOL_GPL(ima_file_check);
/**
- * ima_module_check - based on policy, collect/store/appraise measurement.
- * @file: pointer to the file to be measured/appraised
+ * ima_read_file - pre-measure/appraise hook decision based on policy
+ * @file: pointer to the file to be measured/appraised/audit
+ * @read_id: caller identifier
*
- * Measure/appraise kernel modules based on policy.
+ * Permit reading a file based on policy. The policy rules are written
+ * in terms of the policy identifier. Appraising the integrity of
+ * a file requires a file descriptor.
*
- * On success return 0. On integrity appraisal error, assuming the file
- * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ * For permission return 0, otherwise return -EACCES.
*/
-int ima_module_check(struct file *file)
+int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
{
- if (!file) {
+ if (!file && read_id == READING_MODULE) {
#ifndef CONFIG_MODULE_SIG_FORCE
if ((ima_appraise & IMA_APPRAISE_MODULES) &&
(ima_appraise & IMA_APPRAISE_ENFORCE))
@@ -329,18 +336,53 @@ int ima_module_check(struct file *file)
#endif
return 0; /* We rely on module signature checking */
}
- return process_measurement(file, MAY_EXEC, MODULE_CHECK, 0);
+ return 0;
}
-int ima_fw_from_file(struct file *file, char *buf, size_t size)
+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,
+ [READING_POLICY] = POLICY_CHECK
+};
+
+/**
+ * ima_post_read_file - in memory collect/appraise/audit measurement
+ * @file: pointer to the file to be measured/appraised/audit
+ * @buf: pointer to in memory file contents
+ * @size: size of in memory file contents
+ * @read_id: caller identifier
+ *
+ * Measure/appraise/audit in memory file based on policy. Policy rules
+ * are written in terms of a policy identifier.
+ *
+ * On success return 0. On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_post_read_file(struct file *file, void *buf, loff_t size,
+ enum kernel_read_file_id read_id)
{
- if (!file) {
+ enum ima_hooks func;
+
+ if (!file && read_id == READING_FIRMWARE) {
if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
(ima_appraise & IMA_APPRAISE_ENFORCE))
return -EACCES; /* INTEGRITY_UNKNOWN */
return 0;
}
- return process_measurement(file, MAY_EXEC, FIRMWARE_CHECK, 0);
+
+ if (!file && read_id == READING_MODULE) /* MODULE_SIG_FORCE enabled */
+ return 0;
+
+ if (!file || !buf || size == 0) { /* should never happen */
+ if (ima_appraise & IMA_APPRAISE_ENFORCE)
+ return -EACCES;
+ return 0;
+ }
+
+ func = read_idmap[read_id] ?: FILE_CHECK;
+ return process_measurement(file, buf, size, MAY_READ, func, 0);
}
static int __init init_ima(void)