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| author | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2013-02-21 09:31:22 -0500 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2013-06-20 07:47:50 -0400 |
| commit | 9b97b6cdd420cd62dae972eafaae7494a7670607 (patch) | |
| tree | 4f5958063eb57849e4687e4c5366b1212a1d9d6a /security | |
| parent | d726d8d719b6ac919cc4d5cae73831a2ffe36118 (diff) | |
| download | lwn-9b97b6cdd420cd62dae972eafaae7494a7670607.tar.gz lwn-9b97b6cdd420cd62dae972eafaae7494a7670607.zip | |
evm: audit integrity metadata failures
Before modifying an EVM protected extended attribute or any other
metadata included in the HMAC calculation, the existing 'security.evm'
is verified. This patch adds calls to integrity_audit_msg() to audit
integrity metadata failures.
Reported-by: Sven Vermeulen <sven.vermeulen@siphos.be>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/evm/evm_main.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index cdbde1762189..df0fa451a871 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -16,6 +16,7 @@ #include <linux/module.h> #include <linux/crypto.h> +#include <linux/audit.h> #include <linux/xattr.h> #include <linux/integrity.h> #include <linux/evm.h> @@ -24,6 +25,9 @@ int evm_initialized; +static char *integrity_status_msg[] = { + "pass", "fail", "no_label", "no_xattrs", "unknown" +}; char *evm_hmac = "hmac(sha1)"; char *evm_hash = "sha1"; int evm_hmac_version = CONFIG_EVM_HMAC_VERSION; @@ -262,9 +266,15 @@ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name, if ((evm_status == INTEGRITY_PASS) || (evm_status == INTEGRITY_NOXATTRS)) return 0; - return -EPERM; + goto out; } evm_status = evm_verify_current_integrity(dentry); +out: + if (evm_status != INTEGRITY_PASS) + integrity_audit_msg(AUDIT_INTEGRITY_METADATA, dentry->d_inode, + dentry->d_name.name, "appraise_metadata", + integrity_status_msg[evm_status], + -EPERM, 0); return evm_status == INTEGRITY_PASS ? 0 : -EPERM; } @@ -357,6 +367,9 @@ int evm_inode_setattr(struct dentry *dentry, struct iattr *attr) if ((evm_status == INTEGRITY_PASS) || (evm_status == INTEGRITY_NOXATTRS)) return 0; + integrity_audit_msg(AUDIT_INTEGRITY_METADATA, dentry->d_inode, + dentry->d_name.name, "appraise_metadata", + integrity_status_msg[evm_status], -EPERM, 0); return -EPERM; } |