[PATCH v39 39/42] LSM: Remove lsmblob scaffolding

From: Casey Schaufler
Date: Fri Dec 15 2023 - 17:47:14 EST


Remove the scaffold member from the lsmblob. Remove the
remaining places it is being set.

Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
include/linux/security.h | 6 ------
security/apparmor/audit.c | 6 +-----
security/apparmor/lsm.c | 4 ----
security/apparmor/secid.c | 6 +-----
security/selinux/hooks.c | 14 --------------
security/selinux/ss/services.c | 4 ----
security/smack/smack_lsm.c | 33 ++++-----------------------------
7 files changed, 6 insertions(+), 67 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 529671a89ce0..f7727bf767e5 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -143,11 +143,6 @@ enum lockdown_reason {
LOCKDOWN_CONFIDENTIALITY_MAX,
};

-/* stacking scaffolding */
-struct lsmblob_scaffold {
- u32 secid;
-};
-
/*
* A "security context" is the text representation of
* the information used by LSMs.
@@ -168,7 +163,6 @@ struct lsmblob {
struct lsmblob_smack smack;
struct lsmblob_apparmor apparmor;
struct lsmblob_bpf bpf;
- struct lsmblob_scaffold scaffold;
};

extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
index 72c414d00ba6..d51ab2f1284f 100644
--- a/security/apparmor/audit.c
+++ b/security/apparmor/audit.c
@@ -279,11 +279,7 @@ int aa_audit_rule_match(struct lsmblob *blob, u32 field, u32 op, void *vrule,
if (lsmid != LSM_ID_UNDEF || lsmid != LSM_ID_APPARMOR)
return 0;

- /* stacking scaffolding */
- if (!blob->apparmor.label && blob->scaffold.secid)
- label = aa_secid_to_label(blob->scaffold.secid);
- else
- label = blob->apparmor.label;
+ label = blob->apparmor.label;

if (!label)
return -ENOENT;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index d47816e91bd3..c31d5c008b14 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -984,8 +984,6 @@ static void apparmor_current_getlsmblob_subj(struct lsmblob *blob)
struct aa_label *label = __begin_current_label_crit_section();

blob->apparmor.label = label;
- /* stacking scaffolding */
- blob->scaffold.secid = label->secid;
__end_current_label_crit_section(label);
}

@@ -995,8 +993,6 @@ static void apparmor_task_getlsmblob_obj(struct task_struct *p,
struct aa_label *label = aa_get_task_label(p);

blob->apparmor.label = label;
- /* stacking scaffolding */
- blob->scaffold.secid = label->secid;
aa_put_label(label);
}

diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c
index 1df08372bf1b..e5cfaedf1a9f 100644
--- a/security/apparmor/secid.c
+++ b/security/apparmor/secid.c
@@ -102,11 +102,7 @@ int apparmor_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)

AA_BUG(!seclen);

- /* stacking scaffolding */
- if (!blob->apparmor.label && blob->scaffold.secid)
- label = aa_secid_to_label(blob->scaffold.secid);
- else
- label = blob->apparmor.label;
+ label = blob->apparmor.label;

if (!label)
return -EINVAL;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4ac4b536c568..113ee3df9b5a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3520,8 +3520,6 @@ static void selinux_inode_getlsmblob(struct inode *inode, struct lsmblob *blob)
struct inode_security_struct *isec = inode_security_novalidate(inode);

blob->selinux.secid = isec->sid;
- /* stacking scaffolding */
- blob->scaffold.secid = isec->sid;
}

static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
@@ -4014,8 +4012,6 @@ static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
static void selinux_cred_getlsmblob(const struct cred *c, struct lsmblob *blob)
{
blob->selinux.secid = cred_sid(c);
- /* stacking scaffolding */
- blob->scaffold.secid = blob->selinux.secid;
}

/*
@@ -4156,16 +4152,12 @@ static int selinux_task_getsid(struct task_struct *p)
static void selinux_current_getlsmblob_subj(struct lsmblob *blob)
{
blob->selinux.secid = current_sid();
- /* stacking scaffolding */
- blob->scaffold.secid = blob->selinux.secid;
}

static void selinux_task_getlsmblob_obj(struct task_struct *p,
struct lsmblob *blob)
{
blob->selinux.secid = task_sid_obj(p);
- /* stacking scaffolding */
- blob->scaffold.secid = blob->selinux.secid;
}

static int selinux_task_setnice(struct task_struct *p, int nice)
@@ -6305,8 +6297,6 @@ static void selinux_ipc_getlsmblob(struct kern_ipc_perm *ipcp,
{
struct ipc_security_struct *isec = selinux_ipc(ipcp);
blob->selinux.secid = isec->sid;
- /* stacking scaffolding */
- blob->scaffold.secid = isec->sid;
}

static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
@@ -6609,10 +6599,6 @@ static int selinux_lsmblob_to_secctx(struct lsmblob *blob,
u32 seclen;
u32 ret;

- /* stacking scaffolding */
- if (!secid)
- secid = blob->scaffold.secid;
-
if (cp) {
cp->id = LSM_ID_SELINUX;
ret = security_sid_to_context(secid, &cp->context, &cp->len);
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index eef6655f7730..48211352345e 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3656,10 +3656,6 @@ int selinux_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
goto out;
}

- /* stacking scaffolding */
- if (!blob->selinux.secid && blob->scaffold.secid)
- blob->selinux.secid = blob->scaffold.secid;
-
ctxt = sidtab_search(policy->sidtab, blob->selinux.secid);
if (unlikely(!ctxt)) {
WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 02b9aa200ad4..a486ac42caac 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1644,11 +1644,7 @@ static int smack_inode_listsecurity(struct inode *inode, char *buffer,
*/
static void smack_inode_getlsmblob(struct inode *inode, struct lsmblob *blob)
{
- struct smack_known *skp = smk_of_inode(inode);
-
- blob->smack.skp = skp;
- /* stacking scaffolding */
- blob->scaffold.secid = skp->smk_secid;
+ blob->smack.skp = smk_of_inode(inode);
}

/*
@@ -2156,8 +2152,6 @@ static void smack_cred_getlsmblob(const struct cred *cred,
{
rcu_read_lock();
blob->smack.skp = smk_of_task(smack_cred(cred));
- /* stacking scaffolding */
- blob->scaffold.secid = blob->smack.skp->smk_secid;
rcu_read_unlock();
}

@@ -2259,11 +2253,7 @@ static int smack_task_getsid(struct task_struct *p)
*/
static void smack_current_getlsmblob_subj(struct lsmblob *blob)
{
- struct smack_known *skp = smk_of_current();
-
- blob->smack.skp = skp;
- /* stacking scaffolding */
- blob->scaffold.secid = skp->smk_secid;
+ blob->smack.skp = smk_of_current();
}

/**
@@ -2276,11 +2266,7 @@ static void smack_current_getlsmblob_subj(struct lsmblob *blob)
static void smack_task_getlsmblob_obj(struct task_struct *p,
struct lsmblob *blob)
{
- struct smack_known *skp = smk_of_task_struct_obj(p);
-
- blob->smack.skp = skp;
- /* stacking scaffolding */
- blob->scaffold.secid = skp->smk_secid;
+ blob->smack.skp = smk_of_task_struct_obj(p);
}

/**
@@ -3451,11 +3437,8 @@ static void smack_ipc_getlsmblob(struct kern_ipc_perm *ipp,
struct lsmblob *blob)
{
struct smack_known **iskpp = smack_ipc(ipp);
- struct smack_known *iskp = *iskpp;

- blob->smack.skp = iskp;
- /* stacking scaffolding */
- blob->scaffold.secid = iskp->smk_secid;
+ blob->smack.skp = *iskpp;
}

/**
@@ -4796,10 +4779,6 @@ static int smack_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
return 0;

- /* stacking scaffolding */
- if (!skp && blob->scaffold.secid)
- skp = smack_from_secid(blob->scaffold.secid);
-
/*
* No need to do string comparisons. If a match occurs,
* both pointers will point to the same smack_known
@@ -4862,10 +4841,6 @@ static int smack_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
struct smack_known *skp = blob->smack.skp;
int len;

- /* stacking scaffolding */
- if (!skp && blob->scaffold.secid)
- skp = smack_from_secid(blob->scaffold.secid);
-
len = strlen(skp->smk_known);

if (cp) {
--
2.41.0