[PATCH v39 08/42] LSM: Use lsmblob in security_ipc_getsecid
From: Casey Schaufler
Date: Fri Dec 15 2023 - 17:23:19 EST
There may be more than one LSM that provides IPC data for auditing.
Change security_ipc_getsecid() to fill in a lsmblob structure instead
of the u32 secid. Change the name to security_ipc_getlsmblob() to
reflect the change. The audit data structure containing the secid
will be updated later, so there is a bit of scaffolding here.
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
Acked-by: Stephen Smalley <stephen.smalley.work@xxxxxxxxx>
Acked-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Cc: linux-audit@xxxxxxxxxx
Cc: audit@xxxxxxxxxxxxxxx
---
include/linux/lsm_hook_defs.h | 4 ++--
include/linux/security.h | 18 +++++++++++++++---
kernel/auditsc.c | 3 +--
security/security.c | 14 +++++++-------
security/selinux/hooks.c | 9 ++++++---
security/smack/smack_lsm.c | 17 ++++++++++-------
6 files changed, 41 insertions(+), 24 deletions(-)
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 52d090d1957c..d69332031270 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -234,8 +234,8 @@ LSM_HOOK(void, LSM_RET_VOID, task_to_inode, struct task_struct *p,
struct inode *inode)
LSM_HOOK(int, 0, userns_create, const struct cred *cred)
LSM_HOOK(int, 0, ipc_permission, struct kern_ipc_perm *ipcp, short flag)
-LSM_HOOK(void, LSM_RET_VOID, ipc_getsecid, struct kern_ipc_perm *ipcp,
- u32 *secid)
+LSM_HOOK(void, LSM_RET_VOID, ipc_getlsmblob, struct kern_ipc_perm *ipcp,
+ struct lsmblob *blob)
LSM_HOOK(int, 0, msg_msg_alloc_security, struct msg_msg *msg)
LSM_HOOK(void, LSM_RET_VOID, msg_msg_free_security, struct msg_msg *msg)
LSM_HOOK(int, 0, msg_queue_alloc_security, struct kern_ipc_perm *perm)
diff --git a/include/linux/security.h b/include/linux/security.h
index 029cf071148b..2ca118960234 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -289,6 +289,17 @@ static inline bool lsmblob_is_set(struct lsmblob *blob)
return !!memcmp(blob, &empty, sizeof(*blob));
}
+/**
+ * lsmblob_init - initialize a lsmblob structure
+ * @blob: Pointer to the data to initialize
+ *
+ * Set all secid for all modules to the specified value.
+ */
+static inline void lsmblob_init(struct lsmblob *blob)
+{
+ memset(blob, 0, sizeof(*blob));
+}
+
#ifdef CONFIG_SECURITY
int call_blocking_lsm_notifier(enum lsm_event event, void *data);
@@ -487,7 +498,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
void security_task_to_inode(struct task_struct *p, struct inode *inode);
int security_create_user_ns(const struct cred *cred);
int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
+void security_ipc_getlsmblob(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
int security_msg_msg_alloc(struct msg_msg *msg);
void security_msg_msg_free(struct msg_msg *msg);
int security_msg_queue_alloc(struct kern_ipc_perm *msq);
@@ -1299,9 +1310,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
return 0;
}
-static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+static inline void security_ipc_getlsmblob(struct kern_ipc_perm *ipcp,
+ struct lsmblob *blob)
{
- *secid = 0;
+ lsmblob_init(blob);
}
static inline int security_msg_msg_alloc(struct msg_msg *msg)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 52b4697d938c..89d490db0494 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2638,8 +2638,7 @@ void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
context->ipc.gid = ipcp->gid;
context->ipc.mode = ipcp->mode;
context->ipc.has_perm = 0;
- /* stacking scaffolding */
- security_ipc_getsecid(ipcp, &context->ipc.oblob.scaffold.secid);
+ security_ipc_getlsmblob(ipcp, &context->ipc.oblob);
context->type = AUDIT_IPC;
}
diff --git a/security/security.c b/security/security.c
index 4b78bface040..b82245d55f66 100644
--- a/security/security.c
+++ b/security/security.c
@@ -3595,17 +3595,17 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
}
/**
- * security_ipc_getsecid() - Get the sysv ipc object's secid
+ * security_ipc_getlsmblob() - Get the sysv ipc object LSM data
* @ipcp: ipc permission structure
- * @secid: secid pointer
+ * @blob: pointer to lsm information
*
- * Get the secid associated with the ipc object. In case of failure, @secid
- * will be set to zero.
+ * Get the lsm information associated with the ipc object.
*/
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+
+void security_ipc_getlsmblob(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
{
- *secid = 0;
- call_void_hook(ipc_getsecid, ipcp, secid);
+ lsmblob_init(blob);
+ call_void_hook(ipc_getlsmblob, ipcp, blob);
}
/**
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 83ce496e8ef6..f15991ef6ca8 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6266,10 +6266,13 @@ static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
return ipc_has_perm(ipcp, av);
}
-static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+static void selinux_ipc_getlsmblob(struct kern_ipc_perm *ipcp,
+ struct lsmblob *blob)
{
struct ipc_security_struct *isec = selinux_ipc(ipcp);
- *secid = isec->sid;
+ blob->selinux.secid = isec->sid;
+ /* stacking scaffolding */
+ blob->scaffold.secid = isec->sid;
}
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
@@ -7165,7 +7168,7 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
LSM_HOOK_INIT(userns_create, selinux_userns_create),
LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
- LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
+ LSM_HOOK_INIT(ipc_getlsmblob, selinux_ipc_getlsmblob),
LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index a4ace6ea2ab0..b00f4f44f9c5 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3396,16 +3396,19 @@ static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
}
/**
- * smack_ipc_getsecid - Extract smack security id
+ * smack_ipc_getlsmblob - Extract smack security data
* @ipp: the object permissions
- * @secid: where result will be saved
+ * @blob: where result will be saved
*/
-static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
+static void smack_ipc_getlsmblob(struct kern_ipc_perm *ipp,
+ struct lsmblob *blob)
{
- struct smack_known **blob = smack_ipc(ipp);
- struct smack_known *iskp = *blob;
+ struct smack_known **iskpp = smack_ipc(ipp);
+ struct smack_known *iskp = *iskpp;
- *secid = iskp->smk_secid;
+ blob->smack.skp = iskp;
+ /* stacking scaffolding */
+ blob->scaffold.secid = iskp->smk_secid;
}
/**
@@ -5109,7 +5112,7 @@ static struct security_hook_list smack_hooks[] __ro_after_init = {
LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
- LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
+ LSM_HOOK_INIT(ipc_getlsmblob, smack_ipc_getlsmblob),
LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
--
2.41.0