[PATCH v4 02/19] Smack: Abstract use of cred security blob
From: Casey Schaufler
Date: Fri Sep 21 2018 - 20:17:23 EST
Don't use the cred->security pointer directly.
Provide a helper function that provides the security blob pointer.
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
security/smack/smack.h | 17 +++++++++--
security/smack/smack_access.c | 4 +--
security/smack/smack_lsm.c | 57 +++++++++++++++++------------------
security/smack/smackfs.c | 18 +++++------
4 files changed, 53 insertions(+), 43 deletions(-)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index f7db791fb566..01a922856eba 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -356,6 +356,11 @@ extern struct list_head smack_onlycap_list;
#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 +387,19 @@ static inline struct smack_known *smk_of_task(const struct task_smack *tsp)
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);
+ skp = smk_of_task(smack_cred(cred));
+
rcu_read_unlock();
+
return skp;
}
@@ -405,7 +416,7 @@ static inline struct smack_known *smk_of_forked(const struct task_smack *tsp)
*/
static inline struct smack_known *smk_of_current(void)
{
- return smk_of_task(current_security());
+ return smk_of_task(smack_cred(current_cred()));
}
/*
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 9a4c0ad46518..489d49a20b47 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -275,7 +275,7 @@ int smk_tskacc(struct task_smack *tsp, struct smack_known *obj_known,
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;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 340fc30ad85d..68ee3ae8f25c 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -122,7 +122,7 @@ static int smk_bu_note(char *note, struct smack_known *sskp,
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, struct smack_known *oskp,
#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_struct *otp, int mode, int rc)
#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 *inode, int mode, int rc)
#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, int mode, int rc)
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;
@@ -429,7 +429,7 @@ static int smk_ptrace_rule_check(struct task_struct *tracer,
}
rcu_read_lock();
- tsp = __task_cred(tracer)->security;
+ tsp = smack_cred(__task_cred(tracer));
tracer_known = smk_of_task(tsp);
if ((mode & PTRACE_MODE_ATTACH) &&
@@ -496,7 +496,7 @@ static int smack_ptrace_traceme(struct task_struct *ptp)
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;
@@ -913,7 +913,7 @@ static int smack_sb_statfs(struct dentry *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;
@@ -1744,7 +1744,7 @@ static int smack_mmap_file(struct file *file,
return -EACCES;
mkp = isp->smk_mmap;
- tsp = current_security();
+ tsp = smack_cred(current_cred());
skp = smk_of_current();
rc = 0;
@@ -1840,7 +1840,7 @@ static int smack_file_send_sigiotask(struct task_struct *tsk,
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));
struct file *file;
int rc;
struct smk_audit_info ad;
@@ -1888,7 +1888,7 @@ static int smack_file_receive(struct file *file)
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
@@ -1930,7 +1930,7 @@ static int smack_file_receive(struct file *file)
*/
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;
@@ -1977,7 +1977,7 @@ static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
*/
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;
@@ -2007,7 +2007,7 @@ static void smack_cred_free(struct cred *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;
@@ -2038,15 +2038,14 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old,
*/
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 */
}
@@ -2057,12 +2056,12 @@ static void smack_cred_transfer(struct cred *new, const struct cred *old)
*
* 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();
}
@@ -2076,7 +2075,7 @@ static void smack_cred_getsecid(const struct cred *c, u32 *secid)
*/
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;
@@ -2094,7 +2093,7 @@ static int smack_kernel_create_files_as(struct cred *new,
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;
@@ -2278,7 +2277,7 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info,
* 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;
@@ -3605,7 +3604,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
*/
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;
@@ -3646,7 +3645,7 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
if (new == NULL)
return -ENOMEM;
- tsp = new->security;
+ tsp = smack_cred(new);
tsp->smk_task = skp;
/*
* process can change its label only once
@@ -4291,7 +4290,7 @@ static void smack_inet_csk_clone(struct sock *sk,
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;
@@ -4322,7 +4321,7 @@ static int smack_key_permission(key_ref_t 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;
@@ -4591,7 +4590,7 @@ static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
return -ENOMEM;
}
- tsp = new_creds->security;
+ tsp = smack_cred(new_creds);
/*
* Get label from overlay inode and set it in create_sid
@@ -4619,8 +4618,8 @@ static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
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;
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index f6482e53d55a..9d2dde608298 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -2208,14 +2208,14 @@ static const struct file_operations smk_logging_ops = {
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 inode *inode, struct file *file)
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_load2_ops = {
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 inode *inode, struct file *file)
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_syslog_ops = {
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 inode *inode, struct file *file)
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);
--
2.17.1