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Commit 8c6cb983 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by James Morris
Browse files

tomoyo: Swicth from cred->security to task_struct->security. 



TOMOYO security module is designed to use "struct task_struct"->security
in order to allow per "struct task_struct" tracking without being disturbed
by unable to update "struct cred"->security due to override mechanism.

Now that infrastructure-managed security blob is ready, this patch updates
TOMOYO to use "struct task_struct"->security.

Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarJames Morris <james.morris@microsoft.com>
parent 23711df7

security/tomoyo/common.c

+2 −2
Original line number Diff line number Diff line
@@ -986,7 +986,7 @@ static bool tomoyo_select_domain(struct tomoyo_io_buffer *head, 
		else

			p = find_task_by_vpid(pid);

		if (p)

			domain = tomoyo_real_domain(p);

			domain = tomoyo_task(p)->domain_info;

		rcu_read_unlock();

	} else if (!strncmp(data, "domain=", 7)) {

		if (tomoyo_domain_def(data + 7))
@@ -1668,7 +1668,7 @@ static void tomoyo_read_pid(struct tomoyo_io_buffer *head) 
	else

		p = find_task_by_vpid(pid);

	if (p)

		domain = tomoyo_real_domain(p);

		domain = tomoyo_task(p)->domain_info;

	rcu_read_unlock();

	if (!domain)

		return;

security/tomoyo/common.h

+13 −32
Original line number Diff line number Diff line
@@ -686,7 +686,7 @@ struct tomoyo_domain_info { 
	u8 group;          /* Group number to use.   */

	bool is_deleted;   /* Delete flag.           */

	bool flags[TOMOYO_MAX_DOMAIN_INFO_FLAGS];

	atomic_t users; /* Number of referring credentials. */

	atomic_t users; /* Number of referring tasks. */

};



/*
@@ -913,6 +913,12 @@ struct tomoyo_policy_namespace { 
	const char *name;

};



/* Structure for "struct task_struct"->security. */

struct tomoyo_task {

	struct tomoyo_domain_info *domain_info;

	struct tomoyo_domain_info *old_domain_info;

};



/********** Function prototypes. **********/



bool tomoyo_address_matches_group(const bool is_ipv6, const __be32 *address,
@@ -1021,6 +1027,7 @@ ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head, 
struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param);

struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,

						const bool transit);

struct tomoyo_domain_info *tomoyo_domain(void);

struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname);

struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param,

				      const u8 idx);
@@ -1200,41 +1207,15 @@ static inline void tomoyo_put_group(struct tomoyo_group *group) 
}



/**

 * tomoyo_cred - Get a pointer to the tomoyo cred security blob

 * @cred - the relevant cred

 *

 * Returns pointer to the tomoyo cred blob.

 */

static inline struct tomoyo_domain_info **tomoyo_cred(const struct cred *cred)

{

	return cred->security + tomoyo_blob_sizes.lbs_cred;

}



/**

 * tomoyo_domain - Get "struct tomoyo_domain_info" for current thread.

 * tomoyo_task - Get "struct tomoyo_task" for specified thread.

 *

 * Returns pointer to "struct tomoyo_domain_info" for current thread.

 */

static inline struct tomoyo_domain_info *tomoyo_domain(void)

{

	struct tomoyo_domain_info **blob = tomoyo_cred(current_cred());



	return *blob;

}



/**

 * tomoyo_real_domain - Get "struct tomoyo_domain_info" for specified thread.

 * @task - Pointer to "struct task_struct".

 *

 * @task: Pointer to "struct task_struct".

 *

 * Returns pointer to "struct tomoyo_security" for specified thread.

 * Returns pointer to "struct tomoyo_task" for specified thread.

 */

static inline struct tomoyo_domain_info *tomoyo_real_domain(struct task_struct

							    *task)

static inline struct tomoyo_task *tomoyo_task(struct task_struct *task)

{

	struct tomoyo_domain_info **blob = tomoyo_cred(get_task_cred(task));



	return *blob;

	return task->security + tomoyo_blob_sizes.lbs_task;

}



/**

security/tomoyo/domain.c

+7 −4
Original line number Diff line number Diff line
@@ -678,7 +678,6 @@ static int tomoyo_environ(struct tomoyo_execve *ee) 
 */

int tomoyo_find_next_domain(struct linux_binprm *bprm)

{

	struct tomoyo_domain_info **blob;

	struct tomoyo_domain_info *old_domain = tomoyo_domain();

	struct tomoyo_domain_info *domain = NULL;

	const char *original_name = bprm->filename;
@@ -843,9 +842,13 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm) 
	if (!domain)

		domain = old_domain;

	/* Update reference count on "struct tomoyo_domain_info". */

	{

		struct tomoyo_task *s = tomoyo_task(current);



		s->old_domain_info = s->domain_info;

		s->domain_info = domain;

		atomic_inc(&domain->users);

	blob = tomoyo_cred(bprm->cred);

	*blob = domain;

	}

	kfree(exename.name);

	if (!retval) {

		ee->r.domain = domain;

security/tomoyo/securityfs_if.c

+7 −14
Original line number Diff line number Diff line
@@ -67,23 +67,16 @@ static ssize_t tomoyo_write_self(struct file *file, const char __user *buf, 
			if (!new_domain) {

				error = -ENOENT;

			} else {

				struct cred *cred = prepare_creds();

				if (!cred) {

					error = -ENOMEM;

				} else {

					struct tomoyo_domain_info **blob;

					struct tomoyo_domain_info *old_domain;

				struct tomoyo_task *s = tomoyo_task(current);

				struct tomoyo_domain_info *old_domain =

					s->domain_info;



					blob = tomoyo_cred(cred);

					old_domain = *blob;

					*blob = new_domain;

				s->domain_info = new_domain;

				atomic_inc(&new_domain->users);

				atomic_dec(&old_domain->users);

					commit_creds(cred);

				error = 0;

			}

		}

		}

		tomoyo_read_unlock(idx);

	} else

		error = -EINVAL;

security/tomoyo/tomoyo.c

+79 −70
Original line number Diff line number Diff line
@@ -9,19 +9,19 @@ 
#include "common.h"



/**

 * tomoyo_cred_alloc_blank - Target for security_cred_alloc_blank().

 * tomoyo_domain - Get "struct tomoyo_domain_info" for current thread.

 *

 * @new: Pointer to "struct cred".

 * @gfp: Memory allocation flags.

 *

 * Returns 0.

 * Returns pointer to "struct tomoyo_domain_info" for current thread.

 */

static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)

struct tomoyo_domain_info *tomoyo_domain(void)

{

	struct tomoyo_domain_info **blob = tomoyo_cred(new);

	struct tomoyo_task *s = tomoyo_task(current);



	*blob = NULL;

	return 0;

	if (s->old_domain_info && !current->in_execve) {

		atomic_dec(&s->old_domain_info->users);

		s->old_domain_info = NULL;

	}

	return s->domain_info;

}



/**
@@ -36,85 +36,56 @@ static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp) 
static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,

			       gfp_t gfp)

{

	struct tomoyo_domain_info **old_blob = tomoyo_cred(old);

	struct tomoyo_domain_info **new_blob = tomoyo_cred(new);

	struct tomoyo_domain_info *domain;



	domain = *old_blob;

	*new_blob = domain;

	/* Restore old_domain_info saved by previous execve() request. */

	struct tomoyo_task *s = tomoyo_task(current);



	if (domain)

		atomic_inc(&domain->users);

	return 0;

	if (s->old_domain_info && !current->in_execve) {

		atomic_dec(&s->domain_info->users);

		s->domain_info = s->old_domain_info;

		s->old_domain_info = NULL;

	}



/**

 * tomoyo_cred_transfer - Target for security_transfer_creds().

 *

 * @new: Pointer to "struct cred".

 * @old: Pointer to "struct cred".

 */

static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)

{

	tomoyo_cred_prepare(new, old, 0);

	return 0;

}



/**

 * tomoyo_cred_free - Target for security_cred_free().

 * tomoyo_bprm_committed_creds - Target for security_bprm_committed_creds().

 *

 * @cred: Pointer to "struct cred".

 * @bprm: Pointer to "struct linux_binprm".

 */

static void tomoyo_cred_free(struct cred *cred)

static void tomoyo_bprm_committed_creds(struct linux_binprm *bprm)

{

	struct tomoyo_domain_info **blob = tomoyo_cred(cred);

	struct tomoyo_domain_info *domain = *blob;

	/* Clear old_domain_info saved by execve() request. */

	struct tomoyo_task *s = tomoyo_task(current);



	if (domain)

		atomic_dec(&domain->users);

	atomic_dec(&s->old_domain_info->users);

	s->old_domain_info = NULL;

}



#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER

/**

 * tomoyo_bprm_set_creds - Target for security_bprm_set_creds().

 *

 * @bprm: Pointer to "struct linux_binprm".

 *

 * Returns 0 on success, negative value otherwise.

 * Returns 0.

 */

static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)

{

	struct tomoyo_domain_info **blob;

	struct tomoyo_domain_info *domain;



	/*

	 * Do only if this function is called for the first time of an execve

	 * operation.

	 */

	if (bprm->called_set_creds)

		return 0;

#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER

	/*

	 * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested

	 * for the first time.

	 */

	if (!tomoyo_policy_loaded)

		tomoyo_load_policy(bprm->filename);

#endif

	/*

	 * Release reference to "struct tomoyo_domain_info" stored inside

	 * "bprm->cred->security". New reference to "struct tomoyo_domain_info"

	 * stored inside "bprm->cred->security" will be acquired later inside

	 * tomoyo_find_next_domain().

	 */

	blob = tomoyo_cred(bprm->cred);

	domain = *blob;

	atomic_dec(&domain->users);

	/*

	 * Tell tomoyo_bprm_check_security() is called for the first time of an

	 * execve operation.

	 */

	*blob = NULL;

	return 0;

}

#endif



/**

 * tomoyo_bprm_check_security - Target for security_bprm_check().
@@ -125,16 +96,13 @@ static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) 
 */

static int tomoyo_bprm_check_security(struct linux_binprm *bprm)

{

	struct tomoyo_domain_info **blob;

	struct tomoyo_domain_info *domain;

	struct tomoyo_task *s = tomoyo_task(current);



	blob = tomoyo_cred(bprm->cred);

	domain = *blob;

	/*

	 * Execute permission is checked against pathname passed to do_execve()

	 * using current domain.

	 */

	if (!domain) {

	if (!s->old_domain_info) {

		const int idx = tomoyo_read_lock();

		const int err = tomoyo_find_next_domain(bprm);

		tomoyo_read_unlock(idx);
@@ -143,8 +111,8 @@ static int tomoyo_bprm_check_security(struct linux_binprm *bprm) 
	/*

	 * Read permission is checked against interpreters using next domain.

	 */

	return tomoyo_check_open_permission(domain, &bprm->file->f_path,

					    O_RDONLY);

	return tomoyo_check_open_permission(s->domain_info,

					    &bprm->file->f_path, O_RDONLY);

}



/**
@@ -510,19 +478,60 @@ static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg, 
}



struct lsm_blob_sizes tomoyo_blob_sizes __lsm_ro_after_init = {

	.lbs_cred = sizeof(struct tomoyo_domain_info *),

	.lbs_task = sizeof(struct tomoyo_task),

};



/**

 * tomoyo_task_alloc - Target for security_task_alloc().

 *

 * @task:  Pointer to "struct task_struct".

 * @flags: clone() flags.

 *

 * Returns 0.

 */

static int tomoyo_task_alloc(struct task_struct *task,

			     unsigned long clone_flags)

{

	struct tomoyo_task *old = tomoyo_task(current);

	struct tomoyo_task *new = tomoyo_task(task);



	new->domain_info = old->domain_info;

	atomic_inc(&new->domain_info->users);

	new->old_domain_info = NULL;

	return 0;

}



/**

 * tomoyo_task_free - Target for security_task_free().

 *

 * @task: Pointer to "struct task_struct".

 */

static void tomoyo_task_free(struct task_struct *task)

{

	struct tomoyo_task *s = tomoyo_task(task);



	if (s->domain_info) {

		atomic_dec(&s->domain_info->users);

		s->domain_info = NULL;

	}

	if (s->old_domain_info) {

		atomic_dec(&s->old_domain_info->users);

		s->old_domain_info = NULL;

	}

}



/*

 * tomoyo_security_ops is a "struct security_operations" which is used for

 * registering TOMOYO.

 */

static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = {

	LSM_HOOK_INIT(cred_alloc_blank, tomoyo_cred_alloc_blank),

	LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare),

	LSM_HOOK_INIT(cred_transfer, tomoyo_cred_transfer),

	LSM_HOOK_INIT(cred_free, tomoyo_cred_free),

	LSM_HOOK_INIT(bprm_committed_creds, tomoyo_bprm_committed_creds),

	LSM_HOOK_INIT(task_alloc, tomoyo_task_alloc),

	LSM_HOOK_INIT(task_free, tomoyo_task_free),

#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER

	LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds),

#endif

	LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security),

	LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl),

	LSM_HOOK_INIT(file_open, tomoyo_file_open),
@@ -560,14 +569,14 @@ int tomoyo_enabled __lsm_ro_after_init = 1; 
 */

static int __init tomoyo_init(void)

{

	struct cred *cred = (struct cred *) current_cred();

	struct tomoyo_domain_info **blob;

	struct tomoyo_task *s = tomoyo_task(current);



	/* register ourselves with the security framework */

	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");

	printk(KERN_INFO "TOMOYO Linux initialized\n");

	blob = tomoyo_cred(cred);

	*blob = &tomoyo_kernel_domain;

	s->domain_info = &tomoyo_kernel_domain;

	atomic_inc(&tomoyo_kernel_domain.users);

	s->old_domain_info = NULL;

	tomoyo_mm_init();



	return 0;