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1// SPDX-License-Identifier: GPL-2.02#include "reiserfs.h"3#include <linux/errno.h>4#include <linux/fs.h>5#include <linux/pagemap.h>6#include <linux/xattr.h>7#include <linux/slab.h>8#include "xattr.h"9#include <linux/security.h>10#include <linux/uaccess.h>11 12static int13security_get(const struct xattr_handler *handler, struct dentry *unused,14 struct inode *inode, const char *name, void *buffer, size_t size)15{16 if (IS_PRIVATE(inode))17 return -EPERM;18 19 return reiserfs_xattr_get(inode, xattr_full_name(handler, name),20 buffer, size);21}22 23static int24security_set(const struct xattr_handler *handler,25 struct mnt_idmap *idmap, struct dentry *unused,26 struct inode *inode, const char *name, const void *buffer,27 size_t size, int flags)28{29 if (IS_PRIVATE(inode))30 return -EPERM;31 32 return reiserfs_xattr_set(inode,33 xattr_full_name(handler, name),34 buffer, size, flags);35}36 37static bool security_list(struct dentry *dentry)38{39 return !IS_PRIVATE(d_inode(dentry));40}41 42static int43reiserfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,44 void *fs_info)45{46 struct reiserfs_security_handle *sec = fs_info;47 48 sec->value = kmemdup(xattr_array->value, xattr_array->value_len,49 GFP_KERNEL);50 if (!sec->value)51 return -ENOMEM;52 53 sec->name = xattr_array->name;54 sec->length = xattr_array->value_len;55 return 0;56}57 58/* Initializes the security context for a new inode and returns the number59 * of blocks needed for the transaction. If successful, reiserfs_security60 * must be released using reiserfs_security_free when the caller is done. */61int reiserfs_security_init(struct inode *dir, struct inode *inode,62 const struct qstr *qstr,63 struct reiserfs_security_handle *sec)64{65 int blocks = 0;66 int error;67 68 sec->name = NULL;69 sec->value = NULL;70 sec->length = 0;71 72 /* Don't add selinux attributes on xattrs - they'll never get used */73 if (IS_PRIVATE(dir))74 return 0;75 76 error = security_inode_init_security(inode, dir, qstr,77 &reiserfs_initxattrs, sec);78 if (error) {79 sec->name = NULL;80 sec->value = NULL;81 sec->length = 0;82 return error;83 }84 85 if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {86 blocks = reiserfs_xattr_jcreate_nblocks(inode) +87 reiserfs_xattr_nblocks(inode, sec->length);88 /* We don't want to count the directories twice if we have89 * a default ACL. */90 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;91 }92 return blocks;93}94 95int reiserfs_security_write(struct reiserfs_transaction_handle *th,96 struct inode *inode,97 struct reiserfs_security_handle *sec)98{99 char xattr_name[XATTR_NAME_MAX + 1] = XATTR_SECURITY_PREFIX;100 int error;101 102 if (XATTR_SECURITY_PREFIX_LEN + strlen(sec->name) > XATTR_NAME_MAX)103 return -EINVAL;104 105 strlcat(xattr_name, sec->name, sizeof(xattr_name));106 107 error = reiserfs_xattr_set_handle(th, inode, xattr_name, sec->value,108 sec->length, XATTR_CREATE);109 if (error == -ENODATA || error == -EOPNOTSUPP)110 error = 0;111 112 return error;113}114 115void reiserfs_security_free(struct reiserfs_security_handle *sec)116{117 kfree(sec->value);118 sec->name = NULL;119 sec->value = NULL;120}121 122const struct xattr_handler reiserfs_xattr_security_handler = {123 .prefix = XATTR_SECURITY_PREFIX,124 .get = security_get,125 .set = security_set,126 .list = security_list,127};128