integrity-v6.5

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Merge tag 'integrity-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity subsystem updates from Mimi Zohar:
 "An i_version change, one bug fix, and three kernel doc fixes:

   - instead of IMA detecting file change by directly accesssing
     i_version, it now calls vfs_getattr_nosec().

   - fix a race condition when inserting a new node in the iint rb-tree"

* tag 'integrity-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: Fix build warnings
  evm: Fix build warnings
  evm: Complete description of evm_inode_setattr()
  integrity: Fix possible multiple allocation in integrity_inode_get()
  IMA: use vfs_getattr_nosec to get the i_version

security/integrity/evm/evm_crypto.c

@@ -40,7 +40,7 @@ static const char evm_hmac[] = "hmac(sha1)";
 /**
  * evm_set_key() - set EVM HMAC key from the kernel
  * @key: pointer to a buffer with the key data
- * @size: length of the key data
+ * @keylen: length of the key data
  *
  * This function allows setting the EVM HMAC key from the kernel
  * without using the "encrypted" key subsystem keys. It can be used

security/integrity/evm/evm_main.c

@@ -318,7 +318,6 @@ int evm_protected_xattr_if_enabled(const char *req_xattr_name)
 /**
  * evm_read_protected_xattrs - read EVM protected xattr names, lengths, values
  * @dentry: dentry of the read xattrs
- * @inode: inode of the read xattrs
  * @buffer: buffer xattr names, lengths or values are copied to
  * @buffer_size: size of buffer
  * @type: n: names, l: lengths, v: values
@@ -390,6 +389,7 @@ int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer,
  * @xattr_name: requested xattr
  * @xattr_value: requested xattr value
  * @xattr_value_len: requested xattr value length
+ * @iint: inode integrity metadata
  *
  * Calculate the HMAC for the given dentry and verify it against the stored
  * security.evm xattr. For performance, use the xattr value and length
@@ -795,7 +795,9 @@ static int evm_attr_change(struct mnt_idmap *idmap,
 
 /**
  * evm_inode_setattr - prevent updating an invalid EVM extended attribute
+ * @idmap: idmap of the mount
  * @dentry: pointer to the affected dentry
+ * @attr: iattr structure containing the new file attributes
  *
  * Permit update of file attributes when files have a valid EVM signature,
  * except in the case of them having an immutable portable signature.

security/integrity/iint.c

@@ -43,12 +43,10 @@ static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
 		else if (inode > iint->inode)
 			n = n->rb_right;
 		else
-			break;
-	}
-	if (!n)
-		return NULL;
-
 			return iint;
+	}
+
+	return NULL;
 }
 
 /*
@@ -113,10 +111,15 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
 		parent = *p;
 		test_iint = rb_entry(parent, struct integrity_iint_cache,
 				     rb_node);
-		if (inode < test_iint->inode)
+		if (inode < test_iint->inode) {
 			p = &(*p)->rb_left;
-		else
+		} else if (inode > test_iint->inode) {
 			p = &(*p)->rb_right;
+		} else {
+			write_unlock(&integrity_iint_lock);
+			kmem_cache_free(iint_cache, iint);
+			return test_iint;
+		}
 	}
 
 	iint->inode = inode;

security/integrity/ima/ima_api.c

@@ -13,7 +13,6 @@
 #include <linux/fs.h>
 #include <linux/xattr.h>
 #include <linux/evm.h>
-#include <linux/iversion.h>
 #include <linux/fsverity.h>
 
 #include "ima.h"
@@ -246,10 +245,11 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 	struct inode *inode = file_inode(file);
 	const char *filename = file->f_path.dentry->d_name.name;
 	struct ima_max_digest_data hash;
+	struct kstat stat;
 	int result = 0;
 	int length;
 	void *tmpbuf;
-	u64 i_version;
+	u64 i_version = 0;
 
 	/*
 	 * Always collect the modsig, because IMA might have already collected
@@ -268,7 +268,10 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 	 * to an initial measurement/appraisal/audit, but was modified to
 	 * assume the file changed.
 	 */
-	i_version = inode_query_iversion(inode);
+	result = vfs_getattr_nosec(&file->f_path, &stat, STATX_CHANGE_COOKIE,
+				   AT_STATX_SYNC_AS_STAT);
+	if (!result && (stat.result_mask & STATX_CHANGE_COOKIE))
+		i_version = stat.change_cookie;
 	hash.hdr.algo = algo;
 	hash.hdr.length = hash_digest_size[algo];
 

security/integrity/ima/ima_main.c

@@ -24,7 +24,6 @@
 #include <linux/slab.h>
 #include <linux/xattr.h>
 #include <linux/ima.h>
-#include <linux/iversion.h>
 #include <linux/fs.h>
 
 #include "ima.h"
@@ -164,11 +163,16 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint,
 
 	mutex_lock(&iint->mutex);
 	if (atomic_read(&inode->i_writecount) == 1) {
+		struct kstat stat;
+
 		update = test_and_clear_bit(IMA_UPDATE_XATTR,
 					    &iint->atomic_flags);
-		if (!IS_I_VERSION(inode) ||
-		    !inode_eq_iversion(inode, iint->version) ||
-		    (iint->flags & IMA_NEW_FILE)) {
+		if ((iint->flags & IMA_NEW_FILE) ||
+		    vfs_getattr_nosec(&file->f_path, &stat,
+				      STATX_CHANGE_COOKIE,
+				      AT_STATX_SYNC_AS_STAT) ||
+		    !(stat.result_mask & STATX_CHANGE_COOKIE) ||
+		    stat.change_cookie != iint->version) {
 			iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
 			iint->measured_pcrs = 0;
 			if (update)

security/integrity/ima/ima_modsig.c

@@ -89,6 +89,9 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
 
 /**
  * ima_collect_modsig - Calculate the file hash without the appended signature.
+ * @modsig: parsed module signature
+ * @buf: data to verify the signature on
+ * @size: data size
  *
  * Since the modsig is part of the file contents, the hash used in its signature
  * isn't the same one ordinarily calculated by IMA. Therefore PKCS7 code

security/integrity/ima/ima_policy.c

@@ -721,6 +721,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * @secid: LSM secid of the task to be validated
  * @func: IMA hook identifier
  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ * @flags: IMA actions to consider (e.g. IMA_MEASURE | IMA_APPRAISE)
  * @pcr: set the pcr to extend
  * @template_desc: the template that should be used for this rule
  * @func_data: func specific data, may be NULL
@@ -1915,7 +1916,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 
 /**
  * ima_parse_add_rule - add a rule to ima_policy_rules
- * @rule - ima measurement policy rule
+ * @rule: ima measurement policy rule
  *
  * Avoid locking by allowing just one writer at a time in ima_write_policy()
  * Returns the length of the rule parsed, an error code on failure