Merge tag 'integrity-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity fixes from Mimi Zohar:
 "One bug fix, one performance improvement, and the use of
  static_assert:

   - The bug fix addresses "only a cosmetic change" commit, which didn't
     take into account the original 'ima' template definition.

  - The performance improvement limits the atomic_read()"

* tag 'integrity-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  integrity: Use static_assert() to check struct sizes
  evm: stop avoidably reading i_writecount in evm_file_release
  ima: fix buffer overrun in ima_eventdigest_init_common

3 files changed, 16 insertions, 5 deletions

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 6924ed508ebd..377e57e9084f 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -1084,7 +1084,8 @@ static void evm_file_release(struct file *file)
 	if (!S_ISREG(inode->i_mode) || !(mode & FMODE_WRITE))
 		return;
 
-	if (iint && atomic_read(&inode->i_writecount) == 1)
+	if (iint && iint->flags & EVM_NEW_FILE &&
+	    atomic_read(&inode->i_writecount) == 1)
 		iint->flags &= ~EVM_NEW_FILE;
 }
 
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 4183956c53af..0e627eac9c33 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -318,15 +318,21 @@ static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
 				      hash_algo_name[hash_algo]);
 	}
 
-	if (digest)
+	if (digest) {
 		memcpy(buffer + offset, digest, digestsize);
-	else
+	} else {
 		/*
 		 * If digest is NULL, the event being recorded is a violation.
 		 * Make room for the digest by increasing the offset by the
-		 * hash algorithm digest size.
+		 * hash algorithm digest size. If the hash algorithm is not
+		 * specified increase the offset by IMA_DIGEST_SIZE which
+		 * fits SHA1 or MD5
 		 */
-		offset += hash_digest_size[hash_algo];
+		if (hash_algo < HASH_ALGO__LAST)
+			offset += hash_digest_size[hash_algo];
+		else
+			offset += IMA_DIGEST_SIZE;
+	}
 
 	return ima_write_template_field_data(buffer, offset + digestsize,
 					     fmt, field_data);
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 660f76cb69d3..c2c2da691123 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -37,6 +37,8 @@ struct evm_ima_xattr_data {
 	);
 	u8 data[];
 } __packed;
+static_assert(offsetof(struct evm_ima_xattr_data, data) == sizeof(struct evm_ima_xattr_data_hdr),
+	      "struct member likely outside of __struct_group()");
 
 /* Only used in the EVM HMAC code. */
 struct evm_xattr {
@@ -65,6 +67,8 @@ struct ima_digest_data {
 	);
 	u8 digest[];
 } __packed;
+static_assert(offsetof(struct ima_digest_data, digest) == sizeof(struct ima_digest_data_hdr),
+	      "struct member likely outside of __struct_group()");
 
 /*
  * Instead of wrapping the ima_digest_data struct inside a local structure