[PATCH v8 08/14] ima: Introduce is_signed()
From: Thiago Jung Bauermann <hidden>
Date: 2018-11-16 20:09:08
Also in:
keyrings, linux-crypto, linux-doc, linux-integrity, linux-security-module, lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
With the introduction of another IMA signature type (modsig), some places will need to check for both of them. It is cleaner to do that if there's a helper function to tell whether an xattr_value represents an IMA signature. Suggested-by: Mimi Zohar <redacted> Signed-off-by: Thiago Jung Bauermann <redacted> --- security/integrity/ima/ima.h | 5 +++++ security/integrity/ima/ima_appraise.c | 7 +++---- security/integrity/ima/ima_template_lib.c | 2 +- 3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index cc12f3449a72..e4f72b30cb28 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h@@ -154,6 +154,11 @@ unsigned long ima_get_binary_runtime_size(void); int ima_init_template(void); void ima_init_template_list(void); +static inline bool is_signed(const struct evm_ima_xattr_data *xattr_value) +{ + return xattr_value && xattr_value->type == EVM_IMA_XATTR_DIGSIG; +} + /* * used to protect h_table and sha_table */
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 8bcef90939f8..c6459408e6b2 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c@@ -325,15 +325,14 @@ int ima_appraise_measurement(enum ima_hooks func, } else if (status != INTEGRITY_PASS) { /* Fix mode, but don't replace file signatures. */ if ((ima_appraise & IMA_APPRAISE_FIX) && - (!xattr_value || - xattr_value->type != EVM_IMA_XATTR_DIGSIG)) { + !is_signed(xattr_value)) { if (!ima_fix_xattr(dentry, iint)) status = INTEGRITY_PASS; } /* Permit new files with file signatures, but without data. */ if (inode->i_size == 0 && iint->flags & IMA_NEW_FILE && - xattr_value && xattr_value->type == EVM_IMA_XATTR_DIGSIG) { + is_signed(xattr_value)) { status = INTEGRITY_PASS; }
@@ -448,7 +447,7 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST)) return -EINVAL; ima_reset_appraise_flags(d_backing_inode(dentry), - xvalue->type == EVM_IMA_XATTR_DIGSIG); + is_signed(xvalue)); result = 0; } return result;
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 43752002c222..300912914b17 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c@@ -382,7 +382,7 @@ int ima_eventsig_init(struct ima_event_data *event_data, { struct evm_ima_xattr_data *xattr_value = event_data->xattr_value; - if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG)) + if (!is_signed(xattr_value)) return 0; return ima_write_template_field_data(xattr_value, event_data->xattr_len,