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>
diff --git a/security/security.c b/security/security.c
index 68c1b9b..d23b435 100644
--- a/security/security.c
+++ b/security/security.c
@@ -573,6 +573,9 @@
ret = security_ops->inode_setxattr(dentry, name, value, size, flags);
if (ret)
return ret;
+ ret = ima_inode_setxattr(dentry, name, value, size);
+ if (ret)
+ return ret;
return evm_inode_setxattr(dentry, name, value, size);
}
@@ -608,6 +611,9 @@
ret = security_ops->inode_removexattr(dentry, name);
if (ret)
return ret;
+ ret = ima_inode_removexattr(dentry, name);
+ if (ret)
+ return ret;
return evm_inode_removexattr(dentry, name);
}