Merge tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity updates from Mimi Zohar:
 "Two IMA changes, one EVM change, a use after free bug fix, and a code
  cleanup to address "-Wflex-array-member-not-at-end" warnings:

   - The existing IMA {ascii, binary}_runtime_measurements lists include
     a hard coded SHA1 hash. To address this limitation, define per TPM
     enabled hash algorithm {ascii, binary}_runtime_measurements lists

   - Close an IMA integrity init_module syscall measurement gap by
     defining a new critical-data record

   - Enable (partial) EVM support on stacked filesystems (overlayfs).
     Only EVM portable & immutable file signatures are copied up, since
     they do not contain filesystem specific metadata"

* tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: add crypto agility support for template-hash algorithm
  evm: Rename is_unsupported_fs to is_unsupported_hmac_fs
  fs: Rename SB_I_EVM_UNSUPPORTED to SB_I_EVM_HMAC_UNSUPPORTED
  evm: Enforce signatures on unsupported filesystem for EVM_INIT_X509
  ima: re-evaluate file integrity on file metadata change
  evm: Store and detect metadata inode attributes changes
  ima: Move file-change detection variables into new structure
  evm: Use the metadata inode to calculate metadata hash
  evm: Implement per signature type decision in security_inode_copy_up_xattr
  security: allow finer granularity in permitting copy-up of security xattrs
  ima: Rename backing_inode to real_inode
  integrity: Avoid -Wflex-array-member-not-at-end warnings
  ima: define an init_module critical data record
  ima: Fix use-after-free on a dentry's dname.name

1 files changed, 21 insertions, 11 deletions

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index b37d043d5748..984e861f6e33 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -245,8 +245,10 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file,
 	const char *audit_cause = "failed";
 	struct inode *inode = file_inode(file);
 	struct inode *real_inode = d_real_inode(file_dentry(file));
-	const char *filename = file->f_path.dentry->d_name.name;
 	struct ima_max_digest_data hash;
+	struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
+						struct ima_digest_data, hdr);
+	struct name_snapshot filename;
 	struct kstat stat;
 	int result = 0;
 	int length;
@@ -286,9 +288,9 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file,
 			result = -ENODATA;
 		}
 	} else if (buf) {
-		result = ima_calc_buffer_hash(buf, size, &hash.hdr);
+		result = ima_calc_buffer_hash(buf, size, hash_hdr);
 	} else {
-		result = ima_calc_file_hash(file, &hash.hdr);
+		result = ima_calc_file_hash(file, hash_hdr);
 	}
 
 	if (result && result != -EBADF && result != -EINVAL)
@@ -303,11 +305,11 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file,
 
 	iint->ima_hash = tmpbuf;
 	memcpy(iint->ima_hash, &hash, length);
-	iint->version = i_version;
-	if (real_inode != inode) {
-		iint->real_ino = real_inode->i_ino;
-		iint->real_dev = real_inode->i_sb->s_dev;
-	}
+	if (real_inode == inode)
+		iint->real_inode.version = i_version;
+	else
+		integrity_inode_attrs_store(&iint->real_inode, i_version,
+					    real_inode);
 
 	/* Possibly temporary failure due to type of read (eg. O_DIRECT) */
 	if (!result)
@@ -317,9 +319,13 @@ out:
 		if (file->f_flags & O_DIRECT)
 			audit_cause = "failed(directio)";
 
+		take_dentry_name_snapshot(&filename, file->f_path.dentry);
+
 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
-				    filename, "collect_data", audit_cause,
-				    result, 0);
+				    filename.name.name, "collect_data",
+				    audit_cause, result, 0);
+
+		release_dentry_name_snapshot(&filename);
 	}
 	return result;
 }
@@ -432,6 +438,7 @@ out:
  */
 const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf)
 {
+	struct name_snapshot filename;
 	char *pathname = NULL;
 
 	*pathbuf = __getname();
@@ -445,7 +452,10 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf)
 	}
 
 	if (!pathname) {
-		strscpy(namebuf, path->dentry->d_name.name, NAME_MAX);
+		take_dentry_name_snapshot(&filename, path->dentry);
+		strscpy(namebuf, filename.name.name, NAME_MAX);
+		release_dentry_name_snapshot(&filename);
+
 		pathname = namebuf;
 	}