[REVIEW][PATCH 01/11] sem/security: Pass kern_ipc_perm not sem_array into the sem security hooks

From: Eric W. Biederman
Date: Fri Mar 23 2018 - 15:17:53 EST


All of the implementations of security hooks that take sem_array only
access sem_perm the struct kern_ipc_perm member. This means the
dependencies of the sem security hooks can be simplified by passing
the kern_ipc_perm member of sem_array.

Making this change will allow struct sem and struct sem_array
to become private to ipc/sem.c.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
include/linux/lsm_hooks.h | 10 +++++-----
include/linux/security.h | 21 ++++++++++-----------
ipc/sem.c | 19 ++++++++-----------
security/security.c | 10 +++++-----
security/selinux/hooks.c | 28 ++++++++++++++--------------
security/smack/smack_lsm.c | 22 +++++++++++-----------
6 files changed, 53 insertions(+), 57 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 7161d8e7ee79..e4a94863a88c 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1592,11 +1592,11 @@ union security_list_options {
int (*shm_shmat)(struct shmid_kernel *shp, char __user *shmaddr,
int shmflg);

- int (*sem_alloc_security)(struct sem_array *sma);
- void (*sem_free_security)(struct sem_array *sma);
- int (*sem_associate)(struct sem_array *sma, int semflg);
- int (*sem_semctl)(struct sem_array *sma, int cmd);
- int (*sem_semop)(struct sem_array *sma, struct sembuf *sops,
+ int (*sem_alloc_security)(struct kern_ipc_perm *sma);
+ void (*sem_free_security)(struct kern_ipc_perm *sma);
+ int (*sem_associate)(struct kern_ipc_perm *sma, int semflg);
+ int (*sem_semctl)(struct kern_ipc_perm *sma, int cmd);
+ int (*sem_semop)(struct kern_ipc_perm *sma, struct sembuf *sops,
unsigned nsops, int alter);

int (*netlink_send)(struct sock *sk, struct sk_buff *skb);
diff --git a/include/linux/security.h b/include/linux/security.h
index 73f1ef625d40..fa7adac4b99a 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -36,7 +36,6 @@ struct linux_binprm;
struct cred;
struct rlimit;
struct siginfo;
-struct sem_array;
struct sembuf;
struct kern_ipc_perm;
struct audit_context;
@@ -368,11 +367,11 @@ void security_shm_free(struct shmid_kernel *shp);
int security_shm_associate(struct shmid_kernel *shp, int shmflg);
int security_shm_shmctl(struct shmid_kernel *shp, int cmd);
int security_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, int shmflg);
-int security_sem_alloc(struct sem_array *sma);
-void security_sem_free(struct sem_array *sma);
-int security_sem_associate(struct sem_array *sma, int semflg);
-int security_sem_semctl(struct sem_array *sma, int cmd);
-int security_sem_semop(struct sem_array *sma, struct sembuf *sops,
+int security_sem_alloc(struct kern_ipc_perm *sma);
+void security_sem_free(struct kern_ipc_perm *sma);
+int security_sem_associate(struct kern_ipc_perm *sma, int semflg);
+int security_sem_semctl(struct kern_ipc_perm *sma, int cmd);
+int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops,
unsigned nsops, int alter);
void security_d_instantiate(struct dentry *dentry, struct inode *inode);
int security_getprocattr(struct task_struct *p, char *name, char **value);
@@ -1103,25 +1102,25 @@ static inline int security_shm_shmat(struct shmid_kernel *shp,
return 0;
}

-static inline int security_sem_alloc(struct sem_array *sma)
+static inline int security_sem_alloc(struct kern_ipc_perm *sma)
{
return 0;
}

-static inline void security_sem_free(struct sem_array *sma)
+static inline void security_sem_free(struct kern_ipc_perm *sma)
{ }

-static inline int security_sem_associate(struct sem_array *sma, int semflg)
+static inline int security_sem_associate(struct kern_ipc_perm *sma, int semflg)
{
return 0;
}

-static inline int security_sem_semctl(struct sem_array *sma, int cmd)
+static inline int security_sem_semctl(struct kern_ipc_perm *sma, int cmd)
{
return 0;
}

-static inline int security_sem_semop(struct sem_array *sma,
+static inline int security_sem_semop(struct kern_ipc_perm *sma,
struct sembuf *sops, unsigned nsops,
int alter)
{
diff --git a/ipc/sem.c b/ipc/sem.c
index a4af04979fd2..01f5c63670ae 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -265,7 +265,7 @@ static void sem_rcu_free(struct rcu_head *head)
struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
struct sem_array *sma = container_of(p, struct sem_array, sem_perm);

- security_sem_free(sma);
+ security_sem_free(&sma->sem_perm);
kvfree(sma);
}

@@ -495,7 +495,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
sma->sem_perm.key = key;

sma->sem_perm.security = NULL;
- retval = security_sem_alloc(sma);
+ retval = security_sem_alloc(&sma->sem_perm);
if (retval) {
kvfree(sma);
return retval;
@@ -535,10 +535,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
*/
static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg)
{
- struct sem_array *sma;
-
- sma = container_of(ipcp, struct sem_array, sem_perm);
- return security_sem_associate(sma, semflg);
+ return security_sem_associate(ipcp, semflg);
}

/*
@@ -1209,7 +1206,7 @@ static int semctl_stat(struct ipc_namespace *ns, int semid,
if (ipcperms(ns, &sma->sem_perm, S_IRUGO))
goto out_unlock;

- err = security_sem_semctl(sma, cmd);
+ err = security_sem_semctl(&sma->sem_perm, cmd);
if (err)
goto out_unlock;

@@ -1300,7 +1297,7 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
return -EACCES;
}

- err = security_sem_semctl(sma, SETVAL);
+ err = security_sem_semctl(&sma->sem_perm, SETVAL);
if (err) {
rcu_read_unlock();
return -EACCES;
@@ -1354,7 +1351,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
if (ipcperms(ns, &sma->sem_perm, cmd == SETALL ? S_IWUGO : S_IRUGO))
goto out_rcu_wakeup;

- err = security_sem_semctl(sma, cmd);
+ err = security_sem_semctl(&sma->sem_perm, cmd);
if (err)
goto out_rcu_wakeup;

@@ -1545,7 +1542,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid,

sma = container_of(ipcp, struct sem_array, sem_perm);

- err = security_sem_semctl(sma, cmd);
+ err = security_sem_semctl(&sma->sem_perm, cmd);
if (err)
goto out_unlock1;

@@ -1962,7 +1959,7 @@ static long do_semtimedop(int semid, struct sembuf __user *tsops,
goto out_free;
}

- error = security_sem_semop(sma, sops, nsops, alter);
+ error = security_sem_semop(&sma->sem_perm, sops, nsops, alter);
if (error) {
rcu_read_unlock();
goto out_free;
diff --git a/security/security.c b/security/security.c
index 1cd8526cb0b7..d3b9aeb6b73b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1220,27 +1220,27 @@ int security_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, int shmfl
return call_int_hook(shm_shmat, 0, shp, shmaddr, shmflg);
}

-int security_sem_alloc(struct sem_array *sma)
+int security_sem_alloc(struct kern_ipc_perm *sma)
{
return call_int_hook(sem_alloc_security, 0, sma);
}

-void security_sem_free(struct sem_array *sma)
+void security_sem_free(struct kern_ipc_perm *sma)
{
call_void_hook(sem_free_security, sma);
}

-int security_sem_associate(struct sem_array *sma, int semflg)
+int security_sem_associate(struct kern_ipc_perm *sma, int semflg)
{
return call_int_hook(sem_associate, 0, sma, semflg);
}

-int security_sem_semctl(struct sem_array *sma, int cmd)
+int security_sem_semctl(struct kern_ipc_perm *sma, int cmd)
{
return call_int_hook(sem_semctl, 0, sma, cmd);
}

-int security_sem_semop(struct sem_array *sma, struct sembuf *sops,
+int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops,
unsigned nsops, int alter)
{
return call_int_hook(sem_semop, 0, sma, sops, nsops, alter);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8644d864e3c1..cce994e9fc0a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5767,53 +5767,53 @@ static int selinux_shm_shmat(struct shmid_kernel *shp,
}

/* Semaphore security operations */
-static int selinux_sem_alloc_security(struct sem_array *sma)
+static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
{
struct ipc_security_struct *isec;
struct common_audit_data ad;
u32 sid = current_sid();
int rc;

- rc = ipc_alloc_security(&sma->sem_perm, SECCLASS_SEM);
+ rc = ipc_alloc_security(sma, SECCLASS_SEM);
if (rc)
return rc;

- isec = sma->sem_perm.security;
+ isec = sma->security;

ad.type = LSM_AUDIT_DATA_IPC;
- ad.u.ipc_id = sma->sem_perm.key;
+ ad.u.ipc_id = sma->key;

rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
SEM__CREATE, &ad);
if (rc) {
- ipc_free_security(&sma->sem_perm);
+ ipc_free_security(sma);
return rc;
}
return 0;
}

-static void selinux_sem_free_security(struct sem_array *sma)
+static void selinux_sem_free_security(struct kern_ipc_perm *sma)
{
- ipc_free_security(&sma->sem_perm);
+ ipc_free_security(sma);
}

-static int selinux_sem_associate(struct sem_array *sma, int semflg)
+static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
{
struct ipc_security_struct *isec;
struct common_audit_data ad;
u32 sid = current_sid();

- isec = sma->sem_perm.security;
+ isec = sma->security;

ad.type = LSM_AUDIT_DATA_IPC;
- ad.u.ipc_id = sma->sem_perm.key;
+ ad.u.ipc_id = sma->key;

return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
SEM__ASSOCIATE, &ad);
}

/* Note, at this point, sma is locked down */
-static int selinux_sem_semctl(struct sem_array *sma, int cmd)
+static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
{
int err;
u32 perms;
@@ -5851,11 +5851,11 @@ static int selinux_sem_semctl(struct sem_array *sma, int cmd)
return 0;
}

- err = ipc_has_perm(&sma->sem_perm, perms);
+ err = ipc_has_perm(sma, perms);
return err;
}

-static int selinux_sem_semop(struct sem_array *sma,
+static int selinux_sem_semop(struct kern_ipc_perm *sma,
struct sembuf *sops, unsigned nsops, int alter)
{
u32 perms;
@@ -5865,7 +5865,7 @@ static int selinux_sem_semop(struct sem_array *sma,
else
perms = SEM__READ;

- return ipc_has_perm(&sma->sem_perm, perms);
+ return ipc_has_perm(sma, perms);
}

static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 03fdecba93bb..0402b8c1aec1 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3077,9 +3077,9 @@ static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
*
* Returns a pointer to the smack value
*/
-static struct smack_known *smack_of_sem(struct sem_array *sma)
+static struct smack_known *smack_of_sem(struct kern_ipc_perm *sma)
{
- return (struct smack_known *)sma->sem_perm.security;
+ return (struct smack_known *)sma->security;
}

/**
@@ -3088,9 +3088,9 @@ static struct smack_known *smack_of_sem(struct sem_array *sma)
*
* Returns 0
*/
-static int smack_sem_alloc_security(struct sem_array *sma)
+static int smack_sem_alloc_security(struct kern_ipc_perm *sma)
{
- struct kern_ipc_perm *isp = &sma->sem_perm;
+ struct kern_ipc_perm *isp = sma;
struct smack_known *skp = smk_of_current();

isp->security = skp;
@@ -3103,9 +3103,9 @@ static int smack_sem_alloc_security(struct sem_array *sma)
*
* Clears the blob pointer
*/
-static void smack_sem_free_security(struct sem_array *sma)
+static void smack_sem_free_security(struct kern_ipc_perm *sma)
{
- struct kern_ipc_perm *isp = &sma->sem_perm;
+ struct kern_ipc_perm *isp = sma;

isp->security = NULL;
}
@@ -3117,7 +3117,7 @@ static void smack_sem_free_security(struct sem_array *sma)
*
* Returns 0 if current has the requested access, error code otherwise
*/
-static int smk_curacc_sem(struct sem_array *sma, int access)
+static int smk_curacc_sem(struct kern_ipc_perm *sma, int access)
{
struct smack_known *ssp = smack_of_sem(sma);
struct smk_audit_info ad;
@@ -3125,7 +3125,7 @@ static int smk_curacc_sem(struct sem_array *sma, int access)

#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
- ad.a.u.ipc_id = sma->sem_perm.id;
+ ad.a.u.ipc_id = sma->id;
#endif
rc = smk_curacc(ssp, access, &ad);
rc = smk_bu_current("sem", ssp, access, rc);
@@ -3139,7 +3139,7 @@ static int smk_curacc_sem(struct sem_array *sma, int access)
*
* Returns 0 if current has the requested access, error code otherwise
*/
-static int smack_sem_associate(struct sem_array *sma, int semflg)
+static int smack_sem_associate(struct kern_ipc_perm *sma, int semflg)
{
int may;

@@ -3154,7 +3154,7 @@ static int smack_sem_associate(struct sem_array *sma, int semflg)
*
* Returns 0 if current has the requested access, error code otherwise
*/
-static int smack_sem_semctl(struct sem_array *sma, int cmd)
+static int smack_sem_semctl(struct kern_ipc_perm *sma, int cmd)
{
int may;

@@ -3198,7 +3198,7 @@ static int smack_sem_semctl(struct sem_array *sma, int cmd)
*
* Returns 0 if access is allowed, error code otherwise
*/
-static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
+static int smack_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops,
unsigned nsops, int alter)
{
return smk_curacc_sem(sma, MAY_READWRITE);
--
2.14.1