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authorMimi Zohar <zohar@linux.vnet.ibm.com>2009-02-04 09:07:01 -0500
committerJames Morris <jmorris@namei.org>2009-02-06 09:05:32 +1100
commitf4bd857bc8ed997c25ec06b56ef8064aafa6d4f3 (patch)
tree5326caddadc6144a1e7dee17a6714344ccefbb11 /security/integrity
parent4af4662fa4a9dc62289c580337ae2506339c4729 (diff)
downloadlinux-linaro-stable-f4bd857bc8ed997c25ec06b56ef8064aafa6d4f3.tar.gz
integrity: IMA policy open
Sequentialize access to the policy file - permit multiple attempts to replace default policy with a valid policy Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/integrity')
-rw-r--r--security/integrity/ima/ima_fs.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 95ef1caa64b5..573780c76f1f 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -277,16 +277,30 @@ static struct dentry *runtime_measurements_count;
static struct dentry *violations;
static struct dentry *ima_policy;
+static atomic_t policy_opencount = ATOMIC_INIT(1);
+/*
+ * ima_open_policy: sequentialize access to the policy file
+ */
+int ima_open_policy(struct inode * inode, struct file * filp)
+{
+ if (atomic_dec_and_test(&policy_opencount))
+ return 0;
+ return -EBUSY;
+}
+
/*
* ima_release_policy - start using the new measure policy rules.
*
* Initially, ima_measure points to the default policy rules, now
- * point to the new policy rules, and remove the securityfs policy file.
+ * point to the new policy rules, and remove the securityfs policy file,
+ * assuming a valid policy.
*/
static int ima_release_policy(struct inode *inode, struct file *file)
{
if (!valid_policy) {
ima_delete_rules();
+ valid_policy = 1;
+ atomic_set(&policy_opencount, 1);
return 0;
}
ima_update_policy();
@@ -296,6 +310,7 @@ static int ima_release_policy(struct inode *inode, struct file *file)
}
static struct file_operations ima_measure_policy_ops = {
+ .open = ima_open_policy,
.write = ima_write_policy,
.release = ima_release_policy
};