Commit 52ca4b64 authored Mar 14, 2023 by Roberto Sassu Committed by Paul Moore Mar 23, 2023

reiserfs: Switch to security_inode_init_security()



In preparation for removing security_old_inode_init_security(), switch to
security_inode_init_security(). Commit 572302af ("reiserfs: Add missing
calls to reiserfs_security_free()") fixed possible memory leaks and another
issue related to adding an xattr at inode creation time.

Define the initxattrs callback reiserfs_initxattrs(), to populate the
name/value/len triple in the reiserfs_security_handle() with the first
xattr provided by LSMs. Make a copy of the xattr value, as
security_inode_init_security() frees it.

After the call to security_inode_init_security(), remove the check for
returning -EOPNOTSUPP, as security_inode_init_security() changes it to
zero.

Multiple xattrs are currently not supported, as the
reiserfs_security_handle structure is exported to user space. As a
consequence, even if EVM is invoked, it will not provide an xattr (if it
is not the first to set it, its xattr will be discarded; if it is the
first, it does not have xattrs to calculate the HMAC on).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

parent b9b8701b

fs/reiserfs/xattr_security.c

+18 −5

Original line number	Diff line number	Diff line
		@@ -39,6 +39,22 @@ static bool security_list(struct dentry *dentry)
		return !IS_PRIVATE(d_inode(dentry));
		}

		static int
		reiserfs_initxattrs(struct inode inode, const struct xattr xattr_array,
		void *fs_info)
		{
		struct reiserfs_security_handle *sec = fs_info;

		sec->value = kmemdup(xattr_array->value, xattr_array->value_len,
		GFP_KERNEL);
		if (!sec->value)
		return -ENOMEM;

		sec->name = xattr_array->name;
		sec->length = xattr_array->value_len;
		return 0;
		}

		/* Initializes the security context for a new inode and returns the number
		* of blocks needed for the transaction. If successful, reiserfs_security
		* must be released using reiserfs_security_free when the caller is done. */
		@@ -56,12 +72,9 @@ int reiserfs_security_init(struct inode dir, struct inode inode,
		if (IS_PRIVATE(dir))
		return 0;

		error = security_old_inode_init_security(inode, dir, qstr, &sec->name,
		&sec->value, &sec->length);
		error = security_inode_init_security(inode, dir, qstr,
		&reiserfs_initxattrs, sec);
		if (error) {
		if (error == -EOPNOTSUPP)
		error = 0;

		sec->name = NULL;
		sec->value = NULL;
		sec->length = 0;