0085-Smack-Abstract-use-of-cred-security-blob.patch

From e8239fff0df107e9315c91aeeafdda62c04aec7e Mon Sep 17 00:00:00 2001
From: Casey Schaufler <casey@schaufler-ca.com>
Date: Mon, 27 Aug 2018 14:21:11 -0700
Subject: [PATCH 06/97] Smack: Abstract use of cred security blob

Don't use the cred->security pointer directly.
Provide a helper function that provides the security blob pointer.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/smack/smack.h        |   14 ++++++++--
 security/smack/smack_access.c |    4 +-
 security/smack/smack_lsm.c    |   57 ++++++++++++++++++++----------------------
 security/smack/smackfs.c      |   18 ++++++-------
 4 files changed, 50 insertions(+), 43 deletions(-)

--- dev.orig/security/smack/smack.h
+++ dev/security/smack/smack.h
@@ -356,6 +356,11 @@ extern struct list_head smack_onlycap_li
 #define SMACK_HASH_SLOTS 16
 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS];
 
+static inline struct task_smack *smack_cred(const struct cred *cred)
+{
+	return cred->security;
+}
+
 /*
  * Is the directory transmuting?
  */
@@ -382,13 +387,16 @@ static inline struct smack_known *smk_of
 	return tsp->smk_task;
 }
 
-static inline struct smack_known *smk_of_task_struct(const struct task_struct *t)
+static inline struct smack_known *smk_of_task_struct(
+						const struct task_struct *t)
 {
 	struct smack_known *skp;
+	const struct cred *cred;
 
 	rcu_read_lock();
-	skp = smk_of_task(__task_cred(t)->security);
+	cred = __task_cred(t);
 	rcu_read_unlock();
+	skp = smk_of_task(smack_cred(cred));
 	return skp;
 }
 
@@ -405,7 +413,7 @@ static inline struct smack_known *smk_of
  */
 static inline struct smack_known *smk_of_current(void)
 {
-	return smk_of_task(current_security());
+	return smk_of_task(smack_cred(current_cred()));
 }
 
 /*
--- dev.orig/security/smack/smack_access.c
+++ dev/security/smack/smack_access.c
@@ -275,7 +275,7 @@ out_audit:
 int smk_curacc(struct smack_known *obj_known,
 	       u32 mode, struct smk_audit_info *a)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_tskacc(tsp, obj_known, mode, a);
 }
@@ -635,7 +635,7 @@ DEFINE_MUTEX(smack_onlycap_lock);
  */
 bool smack_privileged_cred(int cap, const struct cred *cred)
 {
-	struct task_smack *tsp = cred->security;
+	struct task_smack *tsp = smack_cred(cred);
 	struct smack_known *skp = tsp->smk_task;
 	struct smack_known_list_elem *sklep;
 	int rc;
--- dev.orig/security/smack/smack_lsm.c
+++ dev/security/smack/smack_lsm.c
@@ -122,7 +122,7 @@ static int smk_bu_note(char *note, struc
 static int smk_bu_current(char *note, struct smack_known *oskp,
 			  int mode, int rc)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 	char acc[SMK_NUM_ACCESS_TYPE + 1];
 
 	if (rc <= 0)
@@ -143,7 +143,7 @@ static int smk_bu_current(char *note, st
 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
 static int smk_bu_task(struct task_struct *otp, int mode, int rc)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 	struct smack_known *smk_task = smk_of_task_struct(otp);
 	char acc[SMK_NUM_ACCESS_TYPE + 1];
 
@@ -165,7 +165,7 @@ static int smk_bu_task(struct task_struc
 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
 static int smk_bu_inode(struct inode *inode, int mode, int rc)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 	struct inode_smack *isp = inode->i_security;
 	char acc[SMK_NUM_ACCESS_TYPE + 1];
 
@@ -195,7 +195,7 @@ static int smk_bu_inode(struct inode *in
 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
 static int smk_bu_file(struct file *file, int mode, int rc)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 	struct smack_known *sskp = tsp->smk_task;
 	struct inode *inode = file_inode(file);
 	struct inode_smack *isp = inode->i_security;
@@ -225,7 +225,7 @@ static int smk_bu_file(struct file *file
 static int smk_bu_credfile(const struct cred *cred, struct file *file,
 				int mode, int rc)
 {
-	struct task_smack *tsp = cred->security;
+	struct task_smack *tsp = smack_cred(cred);
 	struct smack_known *sskp = tsp->smk_task;
 	struct inode *inode = file_inode(file);
 	struct inode_smack *isp = inode->i_security;
@@ -431,7 +431,7 @@ static int smk_ptrace_rule_check(struct
 
 	rcu_read_lock();
 	tracercred = __task_cred(tracer);
-	tsp = tracercred->security;
+	tsp = smack_cred(__task_cred(tracer));
 	tracer_known = smk_of_task(tsp);
 
 	if ((mode & PTRACE_MODE_ATTACH) &&
@@ -498,7 +498,7 @@ static int smack_ptrace_traceme(struct t
 	int rc;
 	struct smack_known *skp;
 
-	skp = smk_of_task(current_security());
+	skp = smk_of_task(smack_cred(current_cred()));
 
 	rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
 	return rc;
@@ -915,7 +915,7 @@ static int smack_sb_statfs(struct dentry
 static int smack_bprm_set_creds(struct linux_binprm *bprm)
 {
 	struct inode *inode = file_inode(bprm->file);
-	struct task_smack *bsp = bprm->cred->security;
+	struct task_smack *bsp = smack_cred(bprm->cred);
 	struct inode_smack *isp;
 	struct superblock_smack *sbsp;
 	int rc;
@@ -1746,7 +1746,7 @@ static int smack_mmap_file(struct file *
 		return -EACCES;
 	mkp = isp->smk_mmap;
 
-	tsp = current_security();
+	tsp = smack_cred(current_cred());
 	skp = smk_of_current();
 	rc = 0;
 
@@ -1842,7 +1842,7 @@ static int smack_file_send_sigiotask(str
 				     struct fown_struct *fown, int signum)
 {
 	struct smack_known *skp;
-	struct smack_known *tkp = smk_of_task(tsk->cred->security);
+	struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
 	const struct cred *tcred;
 	struct file *file;
 	int rc;
@@ -1895,7 +1895,7 @@ static int smack_file_receive(struct fil
 	if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
 		sock = SOCKET_I(inode);
 		ssp = sock->sk->sk_security;
-		tsp = current_security();
+		tsp = smack_cred(current_cred());
 		/*
 		 * If the receiving process can't write to the
 		 * passed socket or if the passed socket can't
@@ -1937,7 +1937,7 @@ static int smack_file_receive(struct fil
  */
 static int smack_file_open(struct file *file)
 {
-	struct task_smack *tsp = file->f_cred->security;
+	struct task_smack *tsp = smack_cred(file->f_cred);
 	struct inode *inode = file_inode(file);
 	struct smk_audit_info ad;
 	int rc;
@@ -1984,7 +1984,7 @@ static int smack_cred_alloc_blank(struct
  */
 static void smack_cred_free(struct cred *cred)
 {
-	struct task_smack *tsp = cred->security;
+	struct task_smack *tsp = smack_cred(cred);
 	struct smack_rule *rp;
 	struct list_head *l;
 	struct list_head *n;
@@ -2014,7 +2014,7 @@ static void smack_cred_free(struct cred
 static int smack_cred_prepare(struct cred *new, const struct cred *old,
 			      gfp_t gfp)
 {
-	struct task_smack *old_tsp = old->security;
+	struct task_smack *old_tsp = smack_cred(old);
 	struct task_smack *new_tsp;
 	int rc;
 
@@ -2045,15 +2045,14 @@ static int smack_cred_prepare(struct cre
  */
 static void smack_cred_transfer(struct cred *new, const struct cred *old)
 {
-	struct task_smack *old_tsp = old->security;
-	struct task_smack *new_tsp = new->security;
+	struct task_smack *old_tsp = smack_cred(old);
+	struct task_smack *new_tsp = smack_cred(new);
 
 	new_tsp->smk_task = old_tsp->smk_task;
 	new_tsp->smk_forked = old_tsp->smk_task;
 	mutex_init(&new_tsp->smk_rules_lock);
 	INIT_LIST_HEAD(&new_tsp->smk_rules);
 
-
 	/* cbs copy rule list */
 }
 
@@ -2064,12 +2063,12 @@ static void smack_cred_transfer(struct c
  *
  * Sets the secid to contain a u32 version of the smack label.
  */
-static void smack_cred_getsecid(const struct cred *c, u32 *secid)
+static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
 {
 	struct smack_known *skp;
 
 	rcu_read_lock();
-	skp = smk_of_task(c->security);
+	skp = smk_of_task(smack_cred(cred));
 	*secid = skp->smk_secid;
 	rcu_read_unlock();
 }
@@ -2083,7 +2082,7 @@ static void smack_cred_getsecid(const st
  */
 static int smack_kernel_act_as(struct cred *new, u32 secid)
 {
-	struct task_smack *new_tsp = new->security;
+	struct task_smack *new_tsp = smack_cred(new);
 
 	new_tsp->smk_task = smack_from_secid(secid);
 	return 0;
@@ -2101,7 +2100,7 @@ static int smack_kernel_create_files_as(
 					struct inode *inode)
 {
 	struct inode_smack *isp = inode->i_security;
-	struct task_smack *tsp = new->security;
+	struct task_smack *tsp = smack_cred(new);
 
 	tsp->smk_forked = isp->smk_inode;
 	tsp->smk_task = tsp->smk_forked;
@@ -2285,7 +2284,7 @@ static int smack_task_kill(struct task_s
 	 * specific behavior. This is not clean. For one thing
 	 * we can't take privilege into account.
 	 */
-	skp = smk_of_task(cred->security);
+	skp = smk_of_task(smack_cred(cred));
 	rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
 	rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
 	return rc;
@@ -3612,7 +3611,7 @@ static int smack_getprocattr(struct task
  */
 static int smack_setprocattr(const char *name, void *value, size_t size)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 	struct cred *new;
 	struct smack_known *skp;
 	struct smack_known_list_elem *sklep;
@@ -3653,7 +3652,7 @@ static int smack_setprocattr(const char
 	if (new == NULL)
 		return -ENOMEM;
 
-	tsp = new->security;
+	tsp = smack_cred(new);
 	tsp->smk_task = skp;
 	/*
 	 * process can change its label only once
@@ -4298,7 +4297,7 @@ static void smack_inet_csk_clone(struct
 static int smack_key_alloc(struct key *key, const struct cred *cred,
 			   unsigned long flags)
 {
-	struct smack_known *skp = smk_of_task(cred->security);
+	struct smack_known *skp = smk_of_task(smack_cred(cred));
 
 	key->security = skp;
 	return 0;
@@ -4329,7 +4328,7 @@ static int smack_key_permission(key_ref_
 {
 	struct key *keyp;
 	struct smk_audit_info ad;
-	struct smack_known *tkp = smk_of_task(cred->security);
+	struct smack_known *tkp = smk_of_task(smack_cred(cred));
 	int request = 0;
 	int rc;
 
@@ -4598,7 +4597,7 @@ static int smack_inode_copy_up(struct de
 			return -ENOMEM;
 	}
 
-	tsp = new_creds->security;
+	tsp = smack_cred(new_creds);
 
 	/*
 	 * Get label from overlay inode and set it in create_sid
@@ -4626,8 +4625,8 @@ static int smack_dentry_create_files_as(
 					const struct cred *old,
 					struct cred *new)
 {
-	struct task_smack *otsp = old->security;
-	struct task_smack *ntsp = new->security;
+	struct task_smack *otsp = smack_cred(old);
+	struct task_smack *ntsp = smack_cred(new);
 	struct inode_smack *isp;
 	int may;
 
--- dev.orig/security/smack/smackfs.c
+++ dev/security/smack/smackfs.c
@@ -2208,14 +2208,14 @@ static const struct file_operations smk_
 
 static void *load_self_seq_start(struct seq_file *s, loff_t *pos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_seq_start(s, pos, &tsp->smk_rules);
 }
 
 static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_seq_next(s, v, pos, &tsp->smk_rules);
 }
@@ -2262,7 +2262,7 @@ static int smk_open_load_self(struct ino
 static ssize_t smk_write_load_self(struct file *file, const char __user *buf,
 			      size_t count, loff_t *ppos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules,
 				    &tsp->smk_rules_lock, SMK_FIXED24_FMT);
@@ -2414,14 +2414,14 @@ static const struct file_operations smk_
 
 static void *load_self2_seq_start(struct seq_file *s, loff_t *pos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_seq_start(s, pos, &tsp->smk_rules);
 }
 
 static void *load_self2_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_seq_next(s, v, pos, &tsp->smk_rules);
 }
@@ -2467,7 +2467,7 @@ static int smk_open_load_self2(struct in
 static ssize_t smk_write_load_self2(struct file *file, const char __user *buf,
 			      size_t count, loff_t *ppos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules,
 				    &tsp->smk_rules_lock, SMK_LONG_FMT);
@@ -2681,14 +2681,14 @@ static const struct file_operations smk_
 
 static void *relabel_self_seq_start(struct seq_file *s, loff_t *pos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_seq_start(s, pos, &tsp->smk_relabel);
 }
 
 static void *relabel_self_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 
 	return smk_seq_next(s, v, pos, &tsp->smk_relabel);
 }
@@ -2736,7 +2736,7 @@ static int smk_open_relabel_self(struct
 static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
 {
-	struct task_smack *tsp = current_security();
+	struct task_smack *tsp = smack_cred(current_cred());
 	char *data;
 	int rc;
 	LIST_HEAD(list_tmp);