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

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
......@@ -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;
......
......@@ -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;
}
/**
......
......@@ -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;
......
......@@ -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;
......
......@@ -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);
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;
}
return 0;
}
/**
* tomoyo_cred_transfer - Target for security_transfer_creds().
* tomoyo_bprm_committed_creds - Target for security_bprm_committed_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);
}
/**
* tomoyo_cred_free - Target for security_cred_free().
*
* @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;
......
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