[PATCH 05/59] LSM: Use lsm_export in the inode_getsecid hooks
Casey Schaufler
casey at schaufler-ca.com
Tue Apr 9 19:58:30 UTC 2019
Convert the inode_getsecid hooks to use the lsm_export
structure instead of a u32 secid. There is some scaffolding
involved that will be removed when security_inode_getsecid()
is updated.
Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
---
include/linux/lsm_hooks.h | 4 ++--
include/linux/security.h | 5 +++++
security/security.c | 35 ++++++++++++++++++++++++++++++++++-
security/selinux/hooks.c | 21 ++++++++++++++++-----
security/smack/smack_lsm.c | 13 +++++++++++--
5 files changed, 68 insertions(+), 10 deletions(-)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 9e3d593a1ec3..baeb83ef487d 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -425,7 +425,7 @@
* @inode_getsecid:
* Get the secid associated with the node.
* @inode contains a pointer to the inode.
- * @secid contains a pointer to the location where result will be saved.
+ * @data contains a pointer to the location where result will be saved.
* In case of failure, @secid will be set to zero.
* @inode_copy_up:
* A file is about to be copied up from lower layer to upper layer of
@@ -1574,7 +1574,7 @@ union security_list_options {
int flags);
int (*inode_listsecurity)(struct inode *inode, char *buffer,
size_t buffer_size);
- void (*inode_getsecid)(struct inode *inode, u32 *secid);
+ void (*inode_getsecid)(struct inode *inode, struct lsm_export *data);
int (*inode_copy_up)(struct dentry *src, struct cred **new);
int (*inode_copy_up_xattr)(const char *name);
diff --git a/include/linux/security.h b/include/linux/security.h
index 81f9f79f9a1e..fb19f41d630b 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -88,6 +88,11 @@ struct lsm_export {
#define LSM_EXPORT_SMACK 0x02
#define LSM_EXPORT_APPARMOR 0x04
+static inline void lsm_export_init(struct lsm_export *l)
+{
+ memset(l, 0, sizeof(*l));
+}
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
diff --git a/security/security.c b/security/security.c
index d05f00a40e82..a1f28a5e582b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -712,6 +712,36 @@ int lsm_superblock_alloc(struct super_block *sb)
RC; \
})
+/**
+ * lsm_export_secid - pull the useful secid out of a lsm_export
+ * @data: the containing data structure
+ * @secid: where to put the one that matters.
+ *
+ * Shim that will disappear when all lsm_export conversions are done.
+ */
+static inline void lsm_export_secid(struct lsm_export *data, u32 *secid)
+{
+ switch (data->flags) {
+ case LSM_EXPORT_NONE:
+ *secid = 0;
+ break;
+ case LSM_EXPORT_SELINUX:
+ *secid = data->selinux;
+ break;
+ case LSM_EXPORT_SMACK:
+ *secid = data->smack;
+ break;
+ case LSM_EXPORT_APPARMOR:
+ *secid = data->apparmor;
+ break;
+ default:
+ pr_warn("%s flags=0x%u - not a valid set\n", __func__,
+ data->flags);
+ *secid = 0;
+ break;
+ }
+}
+
/* Security operations */
int security_binder_set_context_mgr(struct task_struct *mgr)
@@ -1389,7 +1419,10 @@ EXPORT_SYMBOL(security_inode_listsecurity);
void security_inode_getsecid(struct inode *inode, u32 *secid)
{
- call_void_hook(inode_getsecid, inode, secid);
+ struct lsm_export data = { .flags = LSM_EXPORT_NONE };
+
+ call_void_hook(inode_getsecid, inode, &data);
+ lsm_export_secid(&data, secid);
}
int security_inode_copy_up(struct dentry *src, struct cred **new)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ee840fecfebb..0e31be22d9bb 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -213,6 +213,15 @@ static void cred_init_security(void)
tsec->osid = tsec->sid = SECINITSID_KERNEL;
}
+/*
+ * Set the SELinux secid in an lsm_export structure
+ */
+static inline void selinux_export_secid(struct lsm_export *l, u32 secid)
+{
+ l->selinux = secid;
+ l->flags |= LSM_EXPORT_SELINUX;
+}
+
/*
* get the security ID of a set of credentials
*/
@@ -3316,15 +3325,16 @@ static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t
return len;
}
-static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
+static void selinux_inode_getsecid(struct inode *inode, struct lsm_export *l)
{
struct inode_security_struct *isec = inode_security_novalidate(inode);
- *secid = isec->sid;
+
+ selinux_export_secid(l, isec->sid);
}
static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
{
- u32 sid;
+ struct lsm_export l;
struct task_security_struct *tsec;
struct cred *new_creds = *new;
@@ -3336,8 +3346,9 @@ static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
tsec = selinux_cred(new_creds);
/* Get label from overlay inode and set it in create_sid */
- selinux_inode_getsecid(d_inode(src), &sid);
- tsec->create_sid = sid;
+ lsm_export_init(&l);
+ selinux_inode_getsecid(d_inode(src), &l);
+ tsec->create_sid = l.selinux;
*new = new_creds;
return 0;
}
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index e9560b078efe..5e345122ccb1 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -466,6 +466,15 @@ static int smk_ptrace_rule_check(struct task_struct *tracer,
return rc;
}
+/*
+ * Set the Smack secid in an lsm_export structure
+ */
+static inline void smack_export_secid(struct lsm_export *l, u32 secid)
+{
+ l->smack = secid;
+ l->flags |= LSM_EXPORT_SMACK;
+}
+
/*
* LSM hooks.
* We he, that is fun!
@@ -1481,11 +1490,11 @@ static int smack_inode_listsecurity(struct inode *inode, char *buffer,
* @inode: inode to extract the info from
* @secid: where result will be saved
*/
-static void smack_inode_getsecid(struct inode *inode, u32 *secid)
+static void smack_inode_getsecid(struct inode *inode, struct lsm_export *l)
{
struct smack_known *skp = smk_of_inode(inode);
- *secid = skp->smk_secid;
+ smack_export_secid(l, skp->smk_secid);
}
/*
--
2.19.1
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