aboutsummaryrefslogtreecommitdiff
path: root/security/integrity/ima
diff options
context:
space:
mode:
authorMimi Zohar <zohar@linux.vnet.ibm.com>2011-03-10 18:54:15 -0500
committerMimi Zohar <zohar@linux.vnet.ibm.com>2012-09-07 14:57:47 -0400
commit42c63330f2b05aa6077c1bfc2798c04afe54f6b2 (patch)
treebbd7d212ba9c686b2b649718b8b919bdd2eecea4 /security/integrity/ima
parent9957a5043e7b0b7361cdf48eea22b2900293e63a (diff)
downloadlinux-linaro-stable-42c63330f2b05aa6077c1bfc2798c04afe54f6b2.tar.gz
ima: add ima_inode_setxattr/removexattr function and calls
Based on xattr_permission comments, the restriction to modify 'security' xattr is left up to the underlying fs or lsm. Ensure that not just anyone can modify or remove 'security.ima'. Changelog v1: - Unless IMA-APPRAISE is configured, use stub ima_inode_removexattr()/setxattr() functions. (Moved ima_inode_removexattr()/setxattr() to ima_appraise.c) Changelog: - take i_mutex to fix locking (Dmitry Kasatkin) - ima_reset_appraise_flags should only be called when modifying or removing the 'security.ima' xattr. Requires CAP_SYS_ADMIN privilege. (Incorporated fix from Roberto Sassu) - Even if allowed to update security.ima, reset the appraisal flags, forcing re-appraisal. - Replace CAP_MAC_ADMIN with CAP_SYS_ADMIN - static inline ima_inode_setxattr()/ima_inode_removexattr() stubs - ima_protect_xattr should be static Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Diffstat (limited to 'security/integrity/ima')
-rw-r--r--security/integrity/ima/ima_appraise.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 681cb6e72257..becc7e09116d 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -169,3 +169,60 @@ void ima_inode_post_setattr(struct dentry *dentry)
rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA);
return;
}
+
+/*
+ * ima_protect_xattr - protect 'security.ima'
+ *
+ * Ensure that not just anyone can modify or remove 'security.ima'.
+ */
+static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) {
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ return 1;
+ }
+ return 0;
+}
+
+static void ima_reset_appraise_flags(struct inode *inode)
+{
+ struct integrity_iint_cache *iint;
+
+ if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode))
+ return;
+
+ iint = integrity_iint_find(inode);
+ if (!iint)
+ return;
+
+ iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED);
+ return;
+}
+
+int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ int result;
+
+ result = ima_protect_xattr(dentry, xattr_name, xattr_value,
+ xattr_value_len);
+ if (result == 1) {
+ ima_reset_appraise_flags(dentry->d_inode);
+ result = 0;
+ }
+ return result;
+}
+
+int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+{
+ int result;
+
+ result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
+ if (result == 1) {
+ ima_reset_appraise_flags(dentry->d_inode);
+ result = 0;
+ }
+ return result;
+}