Commit 7191adff authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooks 



All of the implementations of security hooks that take shmid_kernel only
access shm_perm the struct kern_ipc_perm member.  This means the
dependencies of the shm security hooks can be simplified by passing
the kern_ipc_perm member of shmid_kernel..

Making this change will allow struct shmid_kernel to become private to ipc/shm.c.

Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent aefad959

include/linux/lsm_hooks.h

+5 −5
Original line number Diff line number Diff line
@@ -1585,11 +1585,11 @@ union security_list_options { 
				struct task_struct *target, long type,

				int mode);



	int (*shm_alloc_security)(struct shmid_kernel *shp);

	void (*shm_free_security)(struct shmid_kernel *shp);

	int (*shm_associate)(struct shmid_kernel *shp, int shmflg);

	int (*shm_shmctl)(struct shmid_kernel *shp, int cmd);

	int (*shm_shmat)(struct shmid_kernel *shp, char __user *shmaddr,

	int (*shm_alloc_security)(struct kern_ipc_perm *shp);

	void (*shm_free_security)(struct kern_ipc_perm *shp);

	int (*shm_associate)(struct kern_ipc_perm *shp, int shmflg);

	int (*shm_shmctl)(struct kern_ipc_perm *shp, int cmd);

	int (*shm_shmat)(struct kern_ipc_perm *shp, char __user *shmaddr,

				int shmflg);



	int (*sem_alloc_security)(struct kern_ipc_perm *sma);

include/linux/security.h

+10 −11
Original line number Diff line number Diff line
@@ -49,7 +49,6 @@ struct qstr; 
struct iattr;

struct fown_struct;

struct file_operations;

struct shmid_kernel;

struct msg_msg;

struct msg_queue;

struct xattr;
@@ -362,11 +361,11 @@ int security_msg_queue_msgsnd(struct msg_queue *msq, 
			      struct msg_msg *msg, int msqflg);

int security_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,

			      struct task_struct *target, long type, int mode);

int security_shm_alloc(struct shmid_kernel *shp);

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_shm_alloc(struct kern_ipc_perm *shp);

void security_shm_free(struct kern_ipc_perm *shp);

int security_shm_associate(struct kern_ipc_perm *shp, int shmflg);

int security_shm_shmctl(struct kern_ipc_perm *shp, int cmd);

int security_shm_shmat(struct kern_ipc_perm *shp, char __user *shmaddr, int shmflg);

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);
@@ -1077,26 +1076,26 @@ static inline int security_msg_queue_msgrcv(struct msg_queue *msq, 
	return 0;

}



static inline int security_shm_alloc(struct shmid_kernel *shp)

static inline int security_shm_alloc(struct kern_ipc_perm *shp)

{

	return 0;

}



static inline void security_shm_free(struct shmid_kernel *shp)

static inline void security_shm_free(struct kern_ipc_perm *shp)

{ }



static inline int security_shm_associate(struct shmid_kernel *shp,

static inline int security_shm_associate(struct kern_ipc_perm *shp,

					 int shmflg)

{

	return 0;

}



static inline int security_shm_shmctl(struct shmid_kernel *shp, int cmd)

static inline int security_shm_shmctl(struct kern_ipc_perm *shp, int cmd)

{

	return 0;

}



static inline int security_shm_shmat(struct shmid_kernel *shp,

static inline int security_shm_shmat(struct kern_ipc_perm *shp,

				     char __user *shmaddr, int shmflg)

{

	return 0;

ipc/shm.c

+7 −10
Original line number Diff line number Diff line
@@ -181,7 +181,7 @@ static void shm_rcu_free(struct rcu_head *head) 
							rcu);

	struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel,

							shm_perm);

	security_shm_free(shp);

	security_shm_free(&shp->shm_perm);

	kvfree(shp);

}
@@ -554,7 +554,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) 
	shp->mlock_user = NULL;



	shp->shm_perm.security = NULL;

	error = security_shm_alloc(shp);

	error = security_shm_alloc(&shp->shm_perm);

	if (error) {

		kvfree(shp);

		return error;
@@ -635,10 +635,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) 
 */

static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)

{

	struct shmid_kernel *shp;



	shp = container_of(ipcp, struct shmid_kernel, shm_perm);

	return security_shm_associate(shp, shmflg);

	return security_shm_associate(ipcp, shmflg);

}



/*
@@ -835,7 +832,7 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, 


	shp = container_of(ipcp, struct shmid_kernel, shm_perm);



	err = security_shm_shmctl(shp, cmd);

	err = security_shm_shmctl(&shp->shm_perm, cmd);

	if (err)

		goto out_unlock1;
@@ -934,7 +931,7 @@ static int shmctl_stat(struct ipc_namespace *ns, int shmid, 
	if (ipcperms(ns, &shp->shm_perm, S_IRUGO))

		goto out_unlock;



	err = security_shm_shmctl(shp, cmd);

	err = security_shm_shmctl(&shp->shm_perm, cmd);

	if (err)

		goto out_unlock;
@@ -978,7 +975,7 @@ static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd) 
	}



	audit_ipc_obj(&(shp->shm_perm));

	err = security_shm_shmctl(shp, cmd);

	err = security_shm_shmctl(&shp->shm_perm, cmd);

	if (err)

		goto out_unlock1;
@@ -1348,7 +1345,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, 
	if (ipcperms(ns, &shp->shm_perm, acc_mode))

		goto out_unlock;



	err = security_shm_shmat(shp, shmaddr, shmflg);

	err = security_shm_shmat(&shp->shm_perm, shmaddr, shmflg);

	if (err)

		goto out_unlock;

security/security.c

+5 −5
Original line number Diff line number Diff line
@@ -1195,27 +1195,27 @@ int security_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 
	return call_int_hook(msg_queue_msgrcv, 0, msq, msg, target, type, mode);

}



int security_shm_alloc(struct shmid_kernel *shp)

int security_shm_alloc(struct kern_ipc_perm *shp)

{

	return call_int_hook(shm_alloc_security, 0, shp);

}



void security_shm_free(struct shmid_kernel *shp)

void security_shm_free(struct kern_ipc_perm *shp)

{

	call_void_hook(shm_free_security, shp);

}



int security_shm_associate(struct shmid_kernel *shp, int shmflg)

int security_shm_associate(struct kern_ipc_perm *shp, int shmflg)

{

	return call_int_hook(shm_associate, 0, shp, shmflg);

}



int security_shm_shmctl(struct shmid_kernel *shp, int cmd)

int security_shm_shmctl(struct kern_ipc_perm *shp, int cmd)

{

	return call_int_hook(shm_shmctl, 0, shp, cmd);

}



int security_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, int shmflg)

int security_shm_shmat(struct kern_ipc_perm *shp, char __user *shmaddr, int shmflg)

{

	return call_int_hook(shm_shmat, 0, shp, shmaddr, shmflg);

}

security/selinux/hooks.c

+14 −14
Original line number Diff line number Diff line
@@ -5674,53 +5674,53 @@ static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 
}



/* Shared Memory security operations */

static int selinux_shm_alloc_security(struct shmid_kernel *shp)

static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)

{

	struct ipc_security_struct *isec;

	struct common_audit_data ad;

	u32 sid = current_sid();

	int rc;



	rc = ipc_alloc_security(&shp->shm_perm, SECCLASS_SHM);

	rc = ipc_alloc_security(shp, SECCLASS_SHM);

	if (rc)

		return rc;



	isec = shp->shm_perm.security;

	isec = shp->security;



	ad.type = LSM_AUDIT_DATA_IPC;

	ad.u.ipc_id = shp->shm_perm.key;

	ad.u.ipc_id = shp->key;



	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,

			  SHM__CREATE, &ad);

	if (rc) {

		ipc_free_security(&shp->shm_perm);

		ipc_free_security(shp);

		return rc;

	}

	return 0;

}



static void selinux_shm_free_security(struct shmid_kernel *shp)

static void selinux_shm_free_security(struct kern_ipc_perm *shp)

{

	ipc_free_security(&shp->shm_perm);

	ipc_free_security(shp);

}



static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)

static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)

{

	struct ipc_security_struct *isec;

	struct common_audit_data ad;

	u32 sid = current_sid();



	isec = shp->shm_perm.security;

	isec = shp->security;



	ad.type = LSM_AUDIT_DATA_IPC;

	ad.u.ipc_id = shp->shm_perm.key;

	ad.u.ipc_id = shp->key;



	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,

			    SHM__ASSOCIATE, &ad);

}



/* Note, at this point, shp is locked down */

static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)

static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)

{

	int perms;

	int err;
@@ -5749,11 +5749,11 @@ static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd) 
		return 0;

	}



	err = ipc_has_perm(&shp->shm_perm, perms);

	err = ipc_has_perm(shp, perms);

	return err;

}



static int selinux_shm_shmat(struct shmid_kernel *shp,

static int selinux_shm_shmat(struct kern_ipc_perm *shp,

			     char __user *shmaddr, int shmflg)

{

	u32 perms;
@@ -5763,7 +5763,7 @@ static int selinux_shm_shmat(struct shmid_kernel *shp, 
	else

		perms = SHM__READ | SHM__WRITE;



	return ipc_has_perm(&shp->shm_perm, perms);

	return ipc_has_perm(shp, perms);

}



/* Semaphore security operations */