Add lsm_name_to_attr(), which translates a text string to a
LSM_ATTR value if one is available.
Add lsm_fill_user_ctx(), which fills a struct lsm_ctx, including
the trailing attribute value.
Both are used in module specific components of LSM system calls.
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
include/linux/security.h | 13 +++++++++++++
security/security.c | 31 +++++++++++++++++++++++++++++++
2 files changed, 44 insertions(+)
diff --git a/include/linux/security.h b/include/linux/security.h
index 21971a635b6a..bf615981b147 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -264,6 +264,7 @@ int unregister_blocking_lsm_notifier(struct notifier_block *nb);
/* prototypes */
extern int security_init(void);
extern int early_security_init(void);
+extern u64 lsm_name_to_attr(const char *name);
/* Security operations */
int security_binder_set_context_mgr(const struct cred *mgr);
@@ -493,6 +494,8 @@ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
int security_locked_down(enum lockdown_reason what);
+int lsm_fill_user_ctx(struct lsm_ctx __user *ctx, void *context,
+ size_t context_size, u64 id, u64 flags);
#else /* CONFIG_SECURITY */
static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data)
@@ -510,6 +513,11 @@ static inline int unregister_blocking_lsm_notifier(struct notifier_block *nb)
return 0;
}
+static inline u64 lsm_name_to_attr(const char *name)
+{
+ return 0;
+}
+
static inline void security_free_mnt_opts(void **mnt_opts)
{
}
@@ -1422,6 +1430,11 @@ static inline int security_locked_down(enum lockdown_reason what)
{
return 0;
}
+static inline int lsm_fill_user_ctx(struct lsm_ctx __user *ctx, void *context,
+ size_t context_size, u64 id, u64 flags)
+{
+ return 0;
+}
#endif /* CONFIG_SECURITY */
#if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE)
diff --git a/security/security.c b/security/security.c
index 6823a6cb32a9..48c883c8d340 100644
--- a/security/security.c
+++ b/security/security.c
@@ -753,6 +753,37 @@ static int lsm_superblock_alloc(struct super_block *sb)
return 0;
}
+/**
+ * lsm_fill_user_ctx - Fill a user space lsm_ctx structure
+ * @ctx: an LSM context to be filled
+ * @context: the new context value
+ * @context_size: the size of the new context value
+ * @id: LSM id
+ * @flags: LSM defined flags
+ *
+ * Fill all of the fields in a user space lsm_ctx structure.
+ * Caller is assumed to have verified that @ctx has enough space
+ * for @context.
+ * Returns 0 on success, -EFAULT on a copyout error.
+ */
+int lsm_fill_user_ctx(struct lsm_ctx __user *ctx, void *context,
+ size_t context_size, u64 id, u64 flags)
+{
+ struct lsm_ctx local;
+ void __user *vc = ctx;
+
+ local.id = id;
+ local.flags = flags;
+ local.ctx_len = context_size;
+ local.len = context_size + sizeof(local);
+ vc += sizeof(local);
+ if (copy_to_user(ctx, &local, sizeof(local)))
+ return -EFAULT;
+ if (context_size > 0 && copy_to_user(vc, context, context_size))
+ return -EFAULT;
+ return 0;
+}
+
/*
* The default value of the LSM hook is defined in linux/lsm_hook_defs.h and
* can be accessed with:
--
2.39.0
