diff options
| -rw-r--r-- | include/linux/security.h | 41 | ||||
| -rw-r--r-- | security/dummy.c | 7 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 59 | ||||
| -rw-r--r-- | security/selinux/include/objsec.h | 1 |
4 files changed, 108 insertions, 0 deletions
diff --git a/include/linux/security.h b/include/linux/security.h index 7aab6ab7c57..d4f3b7a94ea 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -250,6 +250,25 @@ struct swap_info_struct; * @inode contains the inode structure. * Deallocate the inode security structure and set @inode->i_security to * NULL. + * @inode_init_security: + * Obtain the security attribute name suffix and value to set on a newly + * created inode and set up the incore security field for the new inode. + * This hook is called by the fs code as part of the inode creation + * transaction and provides for atomic labeling of the inode, unlike + * the post_create/mkdir/... hooks called by the VFS. The hook function + * is expected to allocate the name and value via kmalloc, with the caller + * being responsible for calling kfree after using them. + * If the security module does not use security attributes or does + * not wish to put a security attribute on this particular inode, + * then it should return -EOPNOTSUPP to skip this processing. + * @inode contains the inode structure of the newly created inode. + * @dir contains the inode structure of the parent directory. + * @name will be set to the allocated name suffix (e.g. selinux). + * @value will be set to the allocated attribute value. + * @len will be set to the length of the value. + * Returns 0 if @name and @value have been successfully set, + * -EOPNOTSUPP if no security attribute is needed, or + * -ENOMEM on memory allocation failure. * @inode_create: * Check permission to create a regular file. * @dir contains inode structure of the parent of the new file. @@ -1080,6 +1099,8 @@ struct security_operations { int (*inode_alloc_security) (struct inode *inode); void (*inode_free_security) (struct inode *inode); + int (*inode_init_security) (struct inode *inode, struct inode *dir, + char **name, void **value, size_t *len); int (*inode_create) (struct inode *dir, struct dentry *dentry, int mode); void (*inode_post_create) (struct inode *dir, @@ -1442,6 +1463,17 @@ static inline void security_inode_free (struct inode *inode) return; security_ops->inode_free_security (inode); } + +static inline int security_inode_init_security (struct inode *inode, + struct inode *dir, + char **name, + void **value, + size_t *len) +{ + if (unlikely (IS_PRIVATE (inode))) + return -EOPNOTSUPP; + return security_ops->inode_init_security (inode, dir, name, value, len); +} static inline int security_inode_create (struct inode *dir, struct dentry *dentry, @@ -2171,6 +2203,15 @@ static inline int security_inode_alloc (struct inode *inode) static inline void security_inode_free (struct inode *inode) { } + +static inline int security_inode_init_security (struct inode *inode, + struct inode *dir, + char **name, + void **value, + size_t *len) +{ + return -EOPNOTSUPP; +} static inline int security_inode_create (struct inode *dir, struct dentry *dentry, diff --git a/security/dummy.c b/security/dummy.c index 6ff88758647..e8a00fa8046 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -258,6 +258,12 @@ static void dummy_inode_free_security (struct inode *inode) return; } +static int dummy_inode_init_security (struct inode *inode, struct inode *dir, + char **name, void **value, size_t *len) +{ + return -EOPNOTSUPP; +} + static int dummy_inode_create (struct inode *inode, struct dentry *dentry, int mask) { @@ -886,6 +892,7 @@ void security_fixup_ops (struct security_operations *ops) set_to_dummy_if_null(ops, sb_post_pivotroot); set_to_dummy_if_null(ops, inode_alloc_security); set_to_dummy_if_null(ops, inode_free_security); + set_to_dummy_if_null(ops, inode_init_security); set_to_dummy_if_null(ops, inode_create); set_to_dummy_if_null(ops, inode_post_create); set_to_dummy_if_null(ops, inode_link); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 8641f8894b4..63701fe0e1a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1274,6 +1274,7 @@ static int post_create(struct inode *dir, struct inode *inode; struct inode_security_struct *dsec; struct superblock_security_struct *sbsec; + struct inode_security_struct *isec; u32 newsid; char *context; unsigned int len; @@ -1293,6 +1294,11 @@ static int post_create(struct inode *dir, return 0; } + isec = inode->i_security; + + if (isec->security_attr_init) + return 0; + if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { newsid = tsec->create_sid; } else { @@ -2018,6 +2024,58 @@ static void selinux_inode_free_security(struct inode *inode) inode_free_security(inode); } +static int selinux_inode_init_security(struct inode *inode, struct inode *dir, + char **name, void **value, + size_t *len) +{ + struct task_security_struct *tsec; + struct inode_security_struct *dsec; + struct superblock_security_struct *sbsec; + struct inode_security_struct *isec; + u32 newsid; + int rc; + char *namep, *context; + + tsec = current->security; + dsec = dir->i_security; + sbsec = dir->i_sb->s_security; + isec = inode->i_security; + + if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { + newsid = tsec->create_sid; + } else { + rc = security_transition_sid(tsec->sid, dsec->sid, + inode_mode_to_security_class(inode->i_mode), + &newsid); + if (rc) { + printk(KERN_WARNING "%s: " + "security_transition_sid failed, rc=%d (dev=%s " + "ino=%ld)\n", + __FUNCTION__, + -rc, inode->i_sb->s_id, inode->i_ino); + return rc; + } + } + + inode_security_set_sid(inode, newsid); + + namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL); + if (!namep) + return -ENOMEM; + *name = namep; + + rc = security_sid_to_context(newsid, &context, len); + if (rc) { + kfree(namep); + return rc; + } + *value = context; + + isec->security_attr_init = 1; + + return 0; +} + static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask) { return may_create(dir, dentry, SECCLASS_FILE); @@ -4298,6 +4356,7 @@ static struct security_operations selinux_ops = { .inode_alloc_security = selinux_inode_alloc_security, .inode_free_security = selinux_inode_free_security, + .inode_init_security = selinux_inode_init_security, .inode_create = selinux_inode_create, .inode_post_create = selinux_inode_post_create, .inode_link = selinux_inode_link, diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 887937c8134..c515bc0b58a 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -46,6 +46,7 @@ struct inode_security_struct { unsigned char initialized; /* initialization flag */ struct semaphore sem; unsigned char inherit; /* inherit SID from parent entry */ + unsigned char security_attr_init; /* security attributes init flag */ }; struct file_security_struct { |