aboutsummaryrefslogtreecommitdiff
path: root/security
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2008-11-14 10:39:23 +1100
committerJames Morris <jmorris@namei.org>2008-11-14 10:39:23 +1100
commitd84f4f992cbd76e8f39c488cf0c5d123843923b1 (patch)
treefc4a0349c42995715b93d0f7a3c78e9ea9b3f36e /security
parent745ca2475a6ac596e3d8d37c2759c0fbe2586227 (diff)
downloadlinux-2.6.38-lt-ux500-d84f4f992cbd76e8f39c488cf0c5d123843923b1.tar.gz
CRED: Inaugurate COW credentials
Inaugurate copy-on-write credentials management. This uses RCU to manage the credentials pointer in the task_struct with respect to accesses by other tasks. A process may only modify its own credentials, and so does not need locking to access or modify its own credentials. A mutex (cred_replace_mutex) is added to the task_struct to control the effect of PTRACE_ATTACHED on credential calculations, particularly with respect to execve(). With this patch, the contents of an active credentials struct may not be changed directly; rather a new set of credentials must be prepared, modified and committed using something like the following sequence of events: struct cred *new = prepare_creds(); int ret = blah(new); if (ret < 0) { abort_creds(new); return ret; } return commit_creds(new); There are some exceptions to this rule: the keyrings pointed to by the active credentials may be instantiated - keyrings violate the COW rule as managing COW keyrings is tricky, given that it is possible for a task to directly alter the keys in a keyring in use by another task. To help enforce this, various pointers to sets of credentials, such as those in the task_struct, are declared const. The purpose of this is compile-time discouragement of altering credentials through those pointers. Once a set of credentials has been made public through one of these pointers, it may not be modified, except under special circumstances: (1) Its reference count may incremented and decremented. (2) The keyrings to which it points may be modified, but not replaced. The only safe way to modify anything else is to create a replacement and commit using the functions described in Documentation/credentials.txt (which will be added by a later patch). This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). This now prepares and commits credentials in various places in the security code rather than altering the current creds directly. (2) Temporary credential overrides. do_coredump() and sys_faccessat() now prepare their own credentials and temporarily override the ones currently on the acting thread, whilst preventing interference from other threads by holding cred_replace_mutex on the thread being dumped. This will be replaced in a future patch by something that hands down the credentials directly to the functions being called, rather than altering the task's objective credentials. (3) LSM interface. A number of functions have been changed, added or removed: (*) security_capset_check(), ->capset_check() (*) security_capset_set(), ->capset_set() Removed in favour of security_capset(). (*) security_capset(), ->capset() New. This is passed a pointer to the new creds, a pointer to the old creds and the proposed capability sets. It should fill in the new creds or return an error. All pointers, barring the pointer to the new creds, are now const. (*) security_bprm_apply_creds(), ->bprm_apply_creds() Changed; now returns a value, which will cause the process to be killed if it's an error. (*) security_task_alloc(), ->task_alloc_security() Removed in favour of security_prepare_creds(). (*) security_cred_free(), ->cred_free() New. Free security data attached to cred->security. (*) security_prepare_creds(), ->cred_prepare() New. Duplicate any security data attached to cred->security. (*) security_commit_creds(), ->cred_commit() New. Apply any security effects for the upcoming installation of new security by commit_creds(). (*) security_task_post_setuid(), ->task_post_setuid() Removed in favour of security_task_fix_setuid(). (*) security_task_fix_setuid(), ->task_fix_setuid() Fix up the proposed new credentials for setuid(). This is used by cap_set_fix_setuid() to implicitly adjust capabilities in line with setuid() changes. Changes are made to the new credentials, rather than the task itself as in security_task_post_setuid(). (*) security_task_reparent_to_init(), ->task_reparent_to_init() Removed. Instead the task being reparented to init is referred directly to init's credentials. NOTE! This results in the loss of some state: SELinux's osid no longer records the sid of the thread that forked it. (*) security_key_alloc(), ->key_alloc() (*) security_key_permission(), ->key_permission() Changed. These now take cred pointers rather than task pointers to refer to the security context. (4) sys_capset(). This has been simplified and uses less locking. The LSM functions it calls have been merged. (5) reparent_to_kthreadd(). This gives the current thread the same credentials as init by simply using commit_thread() to point that way. (6) __sigqueue_alloc() and switch_uid() __sigqueue_alloc() can't stop the target task from changing its creds beneath it, so this function gets a reference to the currently applicable user_struct which it then passes into the sigqueue struct it returns if successful. switch_uid() is now called from commit_creds(), and possibly should be folded into that. commit_creds() should take care of protecting __sigqueue_alloc(). (7) [sg]et[ug]id() and co and [sg]et_current_groups. The set functions now all use prepare_creds(), commit_creds() and abort_creds() to build and check a new set of credentials before applying it. security_task_set[ug]id() is called inside the prepared section. This guarantees that nothing else will affect the creds until we've finished. The calling of set_dumpable() has been moved into commit_creds(). Much of the functionality of set_user() has been moved into commit_creds(). The get functions all simply access the data directly. (8) security_task_prctl() and cap_task_prctl(). security_task_prctl() has been modified to return -ENOSYS if it doesn't want to handle a function, or otherwise return the return value directly rather than through an argument. Additionally, cap_task_prctl() now prepares a new set of credentials, even if it doesn't end up using it. (9) Keyrings. A number of changes have been made to the keyrings code: (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have all been dropped and built in to the credentials functions directly. They may want separating out again later. (b) key_alloc() and search_process_keyrings() now take a cred pointer rather than a task pointer to specify the security context. (c) copy_creds() gives a new thread within the same thread group a new thread keyring if its parent had one, otherwise it discards the thread keyring. (d) The authorisation key now points directly to the credentials to extend the search into rather pointing to the task that carries them. (e) Installing thread, process or session keyrings causes a new set of credentials to be created, even though it's not strictly necessary for process or session keyrings (they're shared). (10) Usermode helper. The usermode helper code now carries a cred struct pointer in its subprocess_info struct instead of a new session keyring pointer. This set of credentials is derived from init_cred and installed on the new process after it has been cloned. call_usermodehelper_setup() allocates the new credentials and call_usermodehelper_freeinfo() discards them if they haven't been used. A special cred function (prepare_usermodeinfo_creds()) is provided specifically for call_usermodehelper_setup() to call. call_usermodehelper_setkeys() adjusts the credentials to sport the supplied keyring as the new session keyring. (11) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) selinux_setprocattr() no longer does its check for whether the current ptracer can access processes with the new SID inside the lock that covers getting the ptracer's SID. Whilst this lock ensures that the check is done with the ptracer pinned, the result is only valid until the lock is released, so there's no point doing it inside the lock. (12) is_single_threaded(). This function has been extracted from selinux_setprocattr() and put into a file of its own in the lib/ directory as join_session_keyring() now wants to use it too. The code in SELinux just checked to see whether a task shared mm_structs with other tasks (CLONE_VM), but that isn't good enough. We really want to know if they're part of the same thread group (CLONE_THREAD). (13) nfsd. The NFS server daemon now has to use the COW credentials to set the credentials it is going to use. It really needs to pass the credentials down to the functions it calls, but it can't do that until other patches in this series have been applied. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security')
-rw-r--r--security/capability.c21
-rw-r--r--security/commoncap.c265
-rw-r--r--security/keys/internal.h17
-rw-r--r--security/keys/key.c25
-rw-r--r--security/keys/keyctl.c95
-rw-r--r--security/keys/keyring.c14
-rw-r--r--security/keys/permission.c24
-rw-r--r--security/keys/proc.c8
-rw-r--r--security/keys/process_keys.c333
-rw-r--r--security/keys/request_key.c29
-rw-r--r--security/keys/request_key_auth.c41
-rw-r--r--security/security.c58
-rw-r--r--security/selinux/hooks.c286
-rw-r--r--security/smack/smack_lsm.c82
14 files changed, 668 insertions, 630 deletions
diff --git a/security/capability.c b/security/capability.c
index fac2f61b69a..efeb6d9e0e6 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -340,12 +340,16 @@ static int cap_task_create(unsigned long clone_flags)
return 0;
}
-static int cap_cred_alloc_security(struct cred *cred)
+static void cap_cred_free(struct cred *cred)
+{
+}
+
+static int cap_cred_prepare(struct cred *new, const struct cred *old, gfp_t gfp)
{
return 0;
}
-static void cap_cred_free(struct cred *cred)
+static void cap_cred_commit(struct cred *new, const struct cred *old)
{
}
@@ -750,7 +754,7 @@ static void cap_release_secctx(char *secdata, u32 seclen)
}
#ifdef CONFIG_KEYS
-static int cap_key_alloc(struct key *key, struct task_struct *ctx,
+static int cap_key_alloc(struct key *key, const struct cred *cred,
unsigned long flags)
{
return 0;
@@ -760,7 +764,7 @@ static void cap_key_free(struct key *key)
{
}
-static int cap_key_permission(key_ref_t key_ref, struct task_struct *context,
+static int cap_key_permission(key_ref_t key_ref, const struct cred *cred,
key_perm_t perm)
{
return 0;
@@ -814,8 +818,7 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, ptrace_may_access);
set_to_cap_if_null(ops, ptrace_traceme);
set_to_cap_if_null(ops, capget);
- set_to_cap_if_null(ops, capset_check);
- set_to_cap_if_null(ops, capset_set);
+ set_to_cap_if_null(ops, capset);
set_to_cap_if_null(ops, acct);
set_to_cap_if_null(ops, capable);
set_to_cap_if_null(ops, quotactl);
@@ -890,10 +893,11 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, file_receive);
set_to_cap_if_null(ops, dentry_open);
set_to_cap_if_null(ops, task_create);
- set_to_cap_if_null(ops, cred_alloc_security);
set_to_cap_if_null(ops, cred_free);
+ set_to_cap_if_null(ops, cred_prepare);
+ set_to_cap_if_null(ops, cred_commit);
set_to_cap_if_null(ops, task_setuid);
- set_to_cap_if_null(ops, task_post_setuid);
+ set_to_cap_if_null(ops, task_fix_setuid);
set_to_cap_if_null(ops, task_setgid);
set_to_cap_if_null(ops, task_setpgid);
set_to_cap_if_null(ops, task_getpgid);
@@ -910,7 +914,6 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, task_wait);
set_to_cap_if_null(ops, task_kill);
set_to_cap_if_null(ops, task_prctl);
- set_to_cap_if_null(ops, task_reparent_to_init);
set_to_cap_if_null(ops, task_to_inode);
set_to_cap_if_null(ops, ipc_permission);
set_to_cap_if_null(ops, ipc_getsecid);
diff --git a/security/commoncap.c b/security/commoncap.c
index 0384bf95db6..b5419273f92 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -72,8 +72,8 @@ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode)
int ret = 0;
rcu_read_lock();
- if (!cap_issubset(child->cred->cap_permitted,
- current->cred->cap_permitted) &&
+ if (!cap_issubset(__task_cred(child)->cap_permitted,
+ current_cred()->cap_permitted) &&
!capable(CAP_SYS_PTRACE))
ret = -EPERM;
rcu_read_unlock();
@@ -85,8 +85,8 @@ int cap_ptrace_traceme(struct task_struct *parent)
int ret = 0;
rcu_read_lock();
- if (!cap_issubset(current->cred->cap_permitted,
- parent->cred->cap_permitted) &&
+ if (!cap_issubset(current_cred()->cap_permitted,
+ __task_cred(parent)->cap_permitted) &&
!has_capability(parent, CAP_SYS_PTRACE))
ret = -EPERM;
rcu_read_unlock();
@@ -117,7 +117,7 @@ static inline int cap_inh_is_capped(void)
* to the old permitted set. That is, if the current task
* does *not* possess the CAP_SETPCAP capability.
*/
- return (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0);
+ return cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0;
}
static inline int cap_limit_ptraced_target(void) { return 1; }
@@ -132,52 +132,39 @@ static inline int cap_limit_ptraced_target(void)
#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */
-int cap_capset_check(const kernel_cap_t *effective,
- const kernel_cap_t *inheritable,
- const kernel_cap_t *permitted)
+int cap_capset(struct cred *new,
+ const struct cred *old,
+ const kernel_cap_t *effective,
+ const kernel_cap_t *inheritable,
+ const kernel_cap_t *permitted)
{
- const struct cred *cred = current->cred;
-
- if (cap_inh_is_capped()
- && !cap_issubset(*inheritable,
- cap_combine(cred->cap_inheritable,
- cred->cap_permitted))) {
+ if (cap_inh_is_capped() &&
+ !cap_issubset(*inheritable,
+ cap_combine(old->cap_inheritable,
+ old->cap_permitted)))
/* incapable of using this inheritable set */
return -EPERM;
- }
+
if (!cap_issubset(*inheritable,
- cap_combine(cred->cap_inheritable,
- cred->cap_bset))) {
+ cap_combine(old->cap_inheritable,
+ old->cap_bset)))
/* no new pI capabilities outside bounding set */
return -EPERM;
- }
/* verify restrictions on target's new Permitted set */
- if (!cap_issubset (*permitted,
- cap_combine (cred->cap_permitted,
- cred->cap_permitted))) {
+ if (!cap_issubset(*permitted, old->cap_permitted))
return -EPERM;
- }
/* verify the _new_Effective_ is a subset of the _new_Permitted_ */
- if (!cap_issubset (*effective, *permitted)) {
+ if (!cap_issubset(*effective, *permitted))
return -EPERM;
- }
+ new->cap_effective = *effective;
+ new->cap_inheritable = *inheritable;
+ new->cap_permitted = *permitted;
return 0;
}
-void cap_capset_set(const kernel_cap_t *effective,
- const kernel_cap_t *inheritable,
- const kernel_cap_t *permitted)
-{
- struct cred *cred = current->cred;
-
- cred->cap_effective = *effective;
- cred->cap_inheritable = *inheritable;
- cred->cap_permitted = *permitted;
-}
-
static inline void bprm_clear_caps(struct linux_binprm *bprm)
{
cap_clear(bprm->cap_post_exec_permitted);
@@ -382,41 +369,46 @@ int cap_bprm_set_security (struct linux_binprm *bprm)
return ret;
}
-void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
+int cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
{
- struct cred *cred = current->cred;
+ const struct cred *old = current_cred();
+ struct cred *new;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- if (bprm->e_uid != cred->uid || bprm->e_gid != cred->gid ||
+ if (bprm->e_uid != old->uid || bprm->e_gid != old->gid ||
!cap_issubset(bprm->cap_post_exec_permitted,
- cred->cap_permitted)) {
+ old->cap_permitted)) {
set_dumpable(current->mm, suid_dumpable);
current->pdeath_signal = 0;
if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
if (!capable(CAP_SETUID)) {
- bprm->e_uid = cred->uid;
- bprm->e_gid = cred->gid;
+ bprm->e_uid = old->uid;
+ bprm->e_gid = old->gid;
}
if (cap_limit_ptraced_target()) {
bprm->cap_post_exec_permitted = cap_intersect(
bprm->cap_post_exec_permitted,
- cred->cap_permitted);
+ new->cap_permitted);
}
}
}
- cred->suid = cred->euid = cred->fsuid = bprm->e_uid;
- cred->sgid = cred->egid = cred->fsgid = bprm->e_gid;
+ new->suid = new->euid = new->fsuid = bprm->e_uid;
+ new->sgid = new->egid = new->fsgid = bprm->e_gid;
/* For init, we want to retain the capabilities set
* in the init_task struct. Thus we skip the usual
* capability rules */
if (!is_global_init(current)) {
- cred->cap_permitted = bprm->cap_post_exec_permitted;
+ new->cap_permitted = bprm->cap_post_exec_permitted;
if (bprm->cap_effective)
- cred->cap_effective = bprm->cap_post_exec_permitted;
+ new->cap_effective = bprm->cap_post_exec_permitted;
else
- cap_clear(cred->cap_effective);
+ cap_clear(new->cap_effective);
}
/*
@@ -431,15 +423,15 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
* Number 1 above might fail if you don't have a full bset, but I think
* that is interesting information to audit.
*/
- if (!cap_isclear(cred->cap_effective)) {
- if (!cap_issubset(CAP_FULL_SET, cred->cap_effective) ||
- (bprm->e_uid != 0) || (cred->uid != 0) ||
+ if (!cap_isclear(new->cap_effective)) {
+ if (!cap_issubset(CAP_FULL_SET, new->cap_effective) ||
+ bprm->e_uid != 0 || new->uid != 0 ||
issecure(SECURE_NOROOT))
- audit_log_bprm_fcaps(bprm, &cred->cap_permitted,
- &cred->cap_effective);
+ audit_log_bprm_fcaps(bprm, new, old);
}
- cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
+ new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
+ return commit_creds(new);
}
int cap_bprm_secureexec (struct linux_binprm *bprm)
@@ -514,65 +506,49 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name)
* files..
* Thanks to Olaf Kirch and Peter Benie for spotting this.
*/
-static inline void cap_emulate_setxuid (int old_ruid, int old_euid,
- int old_suid)
+static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old)
{
- struct cred *cred = current->cred;
-
- if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) &&
- (cred->uid != 0 && cred->euid != 0 && cred->suid != 0) &&
+ if ((old->uid == 0 || old->euid == 0 || old->suid == 0) &&
+ (new->uid != 0 && new->euid != 0 && new->suid != 0) &&
!issecure(SECURE_KEEP_CAPS)) {
- cap_clear(cred->cap_permitted);
- cap_clear(cred->cap_effective);
- }
- if (old_euid == 0 && cred->euid != 0) {
- cap_clear(cred->cap_effective);
- }
- if (old_euid != 0 && cred->euid == 0) {
- cred->cap_effective = cred->cap_permitted;
+ cap_clear(new->cap_permitted);
+ cap_clear(new->cap_effective);
}
+ if (old->euid == 0 && new->euid != 0)
+ cap_clear(new->cap_effective);
+ if (old->euid != 0 && new->euid == 0)
+ new->cap_effective = new->cap_permitted;
}
-int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid,
- int flags)
+int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
{
- struct cred *cred = current->cred;
-
switch (flags) {
case LSM_SETID_RE:
case LSM_SETID_ID:
case LSM_SETID_RES:
/* Copied from kernel/sys.c:setreuid/setuid/setresuid. */
- if (!issecure (SECURE_NO_SETUID_FIXUP)) {
- cap_emulate_setxuid (old_ruid, old_euid, old_suid);
- }
+ if (!issecure(SECURE_NO_SETUID_FIXUP))
+ cap_emulate_setxuid(new, old);
break;
case LSM_SETID_FS:
- {
- uid_t old_fsuid = old_ruid;
-
- /* Copied from kernel/sys.c:setfsuid. */
+ /* Copied from kernel/sys.c:setfsuid. */
- /*
- * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
- * if not, we might be a bit too harsh here.
- */
-
- if (!issecure (SECURE_NO_SETUID_FIXUP)) {
- if (old_fsuid == 0 && cred->fsuid != 0) {
- cred->cap_effective =
- cap_drop_fs_set(
- cred->cap_effective);
- }
- if (old_fsuid != 0 && cred->fsuid == 0) {
- cred->cap_effective =
- cap_raise_fs_set(
- cred->cap_effective,
- cred->cap_permitted);
- }
+ /*
+ * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
+ * if not, we might be a bit too harsh here.
+ */
+ if (!issecure(SECURE_NO_SETUID_FIXUP)) {
+ if (old->fsuid == 0 && new->fsuid != 0) {
+ new->cap_effective =
+ cap_drop_fs_set(new->cap_effective);
+ }
+ if (old->fsuid != 0 && new->fsuid == 0) {
+ new->cap_effective =
+ cap_raise_fs_set(new->cap_effective,
+ new->cap_permitted);
}
- break;
}
+ break;
default:
return -EINVAL;
}
@@ -628,13 +604,14 @@ int cap_task_setnice (struct task_struct *p, int nice)
* this task could get inconsistent info. There can be no
* racing writer bc a task can only change its own caps.
*/
-static long cap_prctl_drop(unsigned long cap)
+static long cap_prctl_drop(struct cred *new, unsigned long cap)
{
if (!capable(CAP_SETPCAP))
return -EPERM;
if (!cap_valid(cap))
return -EINVAL;
- cap_lower(current->cred->cap_bset, cap);
+
+ cap_lower(new->cap_bset, cap);
return 0;
}
@@ -655,22 +632,29 @@ int cap_task_setnice (struct task_struct *p, int nice)
#endif
int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
- unsigned long arg4, unsigned long arg5, long *rc_p)
+ unsigned long arg4, unsigned long arg5)
{
- struct cred *cred = current_cred();
+ struct cred *new;
long error = 0;
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
switch (option) {
case PR_CAPBSET_READ:
+ error = -EINVAL;
if (!cap_valid(arg2))
- error = -EINVAL;
- else
- error = !!cap_raised(cred->cap_bset, arg2);
- break;
+ goto error;
+ error = !!cap_raised(new->cap_bset, arg2);
+ goto no_change;
+
#ifdef CONFIG_SECURITY_FILE_CAPABILITIES
case PR_CAPBSET_DROP:
- error = cap_prctl_drop(arg2);
- break;
+ error = cap_prctl_drop(new, arg2);
+ if (error < 0)
+ goto error;
+ goto changed;
/*
* The next four prctl's remain to assist with transitioning a
@@ -692,12 +676,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
* capability-based-privilege environment.
*/
case PR_SET_SECUREBITS:
- if ((((cred->securebits & SECURE_ALL_LOCKS) >> 1)
- & (cred->securebits ^ arg2)) /*[1]*/
- || ((cred->securebits & SECURE_ALL_LOCKS
- & ~arg2)) /*[2]*/
- || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
- || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0)) { /*[4]*/
+ error = -EPERM;
+ if ((((new->securebits & SECURE_ALL_LOCKS) >> 1)
+ & (new->securebits ^ arg2)) /*[1]*/
+ || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
+ || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
+ || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/
/*
* [1] no changing of bits that are locked
* [2] no unlocking of locks
@@ -705,50 +689,51 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
* [4] doing anything requires privilege (go read about
* the "sendmail capabilities bug")
*/
- error = -EPERM; /* cannot change a locked bit */
- } else {
- cred->securebits = arg2;
- }
- break;
+ )
+ /* cannot change a locked bit */
+ goto error;
+ new->securebits = arg2;
+ goto changed;
+
case PR_GET_SECUREBITS:
- error = cred->securebits;
- break;
+ error = new->securebits;
+ goto no_change;
#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */
case PR_GET_KEEPCAPS:
if (issecure(SECURE_KEEP_CAPS))
error = 1;
- break;
+ goto no_change;
+
case PR_SET_KEEPCAPS:
+ error = -EINVAL;
if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */
- error = -EINVAL;
- else if (issecure(SECURE_KEEP_CAPS_LOCKED))
- error = -EPERM;
- else if (arg2)
- cred->securebits |= issecure_mask(SECURE_KEEP_CAPS);
+ goto error;
+ error = -EPERM;
+ if (issecure(SECURE_KEEP_CAPS_LOCKED))
+ goto error;
+ if (arg2)
+ new->securebits |= issecure_mask(SECURE_KEEP_CAPS);
else
- cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
- break;
+ new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
+ goto changed;
default:
/* No functionality available - continue with default */
- return 0;
+ error = -ENOSYS;
+ goto error;
}
/* Functionality provided */
- *rc_p = error;
- return 1;
-}
-
-void cap_task_reparent_to_init (struct task_struct *p)
-{
- struct cred *cred = p->cred;
-
- cap_set_init_eff(cred->cap_effective);
- cap_clear(cred->cap_inheritable);
- cap_set_full(cred->cap_permitted);
- p->cred->securebits = SECUREBITS_DEFAULT;
+changed:
+ return commit_creds(new);
+
+no_change:
+ error = 0;
+error:
+ abort_creds(new);
+ return error;
}
int cap_syslog (int type)
diff --git a/security/keys/internal.h b/security/keys/internal.h
index d1586c62978..81932abefe7 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -12,6 +12,7 @@
#ifndef _INTERNAL_H
#define _INTERNAL_H
+#include <linux/sched.h>
#include <linux/key-type.h>
static inline __attribute__((format(printf, 1, 2)))
@@ -25,7 +26,7 @@ void no_printk(const char *fmt, ...)
#define kleave(FMT, ...) \
printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) \
- printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
+ printk(KERN_DEBUG " "FMT"\n", ##__VA_ARGS__)
#else
#define kenter(FMT, ...) \
no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
@@ -97,7 +98,7 @@ extern struct key *keyring_search_instkey(struct key *keyring,
typedef int (*key_match_func_t)(const struct key *, const void *);
extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
- struct task_struct *tsk,
+ const struct cred *cred,
struct key_type *type,
const void *description,
key_match_func_t match);
@@ -105,13 +106,13 @@ extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
extern key_ref_t search_process_keyrings(struct key_type *type,
const void *description,
key_match_func_t match,
- struct task_struct *tsk);
+ const struct cred *cred);
extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
extern int install_user_keyrings(void);
-extern int install_thread_keyring(void);
-extern int install_process_keyring(void);
+extern int install_thread_keyring_to_cred(struct cred *);
+extern int install_process_keyring_to_cred(struct cred *);
extern struct key *request_key_and_link(struct key_type *type,
const char *description,
@@ -130,12 +131,12 @@ extern long join_session_keyring(const char *name);
* check to see whether permission is granted to use a key in the desired way
*/
extern int key_task_permission(const key_ref_t key_ref,
- struct task_struct *context,
+ const struct cred *cred,
key_perm_t perm);
static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
{
- return key_task_permission(key_ref, current, perm);
+ return key_task_permission(key_ref, current_cred(), perm);
}
/* required permissions */
@@ -153,7 +154,7 @@ static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
struct request_key_auth {
struct key *target_key;
struct key *dest_keyring;
- struct task_struct *context;
+ const struct cred *cred;
void *callout_info;
size_t callout_len;
pid_t pid;
diff --git a/security/keys/key.c b/security/keys/key.c
index a6ca39ed3b0..f76c8a546fd 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -218,7 +218,7 @@ serial_exists:
* instantiate the key or discard it before returning
*/
struct key *key_alloc(struct key_type *type, const char *desc,
- uid_t uid, gid_t gid, struct task_struct *ctx,
+ uid_t uid, gid_t gid, const struct cred *cred,
key_perm_t perm, unsigned long flags)
{
struct key_user *user = NULL;
@@ -294,7 +294,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
#endif
/* let the security module know about the key */
- ret = security_key_alloc(key, ctx, flags);
+ ret = security_key_alloc(key, cred, flags);
if (ret < 0)
goto security_error;
@@ -391,7 +391,7 @@ static int __key_instantiate_and_link(struct key *key,
const void *data,
size_t datalen,
struct key *keyring,
- struct key *instkey)
+ struct key *authkey)
{
int ret, awaken;
@@ -421,8 +421,8 @@ static int __key_instantiate_and_link(struct key *key,
ret = __key_link(keyring, key);
/* disable the authorisation key */
- if (instkey)
- key_revoke(instkey);
+ if (authkey)
+ key_revoke(authkey);
}
}
@@ -444,14 +444,14 @@ int key_instantiate_and_link(struct key *key,
const void *data,
size_t datalen,
struct key *keyring,
- struct key *instkey)
+ struct key *authkey)
{
int ret;
if (keyring)
down_write(&keyring->sem);
- ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey);
+ ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey);
if (keyring)
up_write(&keyring->sem);
@@ -469,7 +469,7 @@ EXPORT_SYMBOL(key_instantiate_and_link);
int key_negate_and_link(struct key *key,
unsigned timeout,
struct key *keyring,
- struct key *instkey)
+ struct key *authkey)
{
struct timespec now;
int ret, awaken;
@@ -504,8 +504,8 @@ int key_negate_and_link(struct key *key,
ret = __key_link(keyring, key);
/* disable the authorisation key */
- if (instkey)
- key_revoke(instkey);
+ if (authkey)
+ key_revoke(authkey);
}
mutex_unlock(&key_construction_mutex);
@@ -743,6 +743,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
key_perm_t perm,
unsigned long flags)
{
+ const struct cred *cred = current_cred();
struct key_type *ktype;
struct key *keyring, *key = NULL;
key_ref_t key_ref;
@@ -802,8 +803,8 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
}
/* allocate a new key */
- key = key_alloc(ktype, description, current_fsuid(), current_fsgid(),
- current, perm, flags);
+ key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred,
+ perm, flags);
if (IS_ERR(key)) {
key_ref = ERR_CAST(key);
goto error_3;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 8833b447ade..7c72baa02f2 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -866,6 +866,23 @@ static long get_instantiation_keyring(key_serial_t ringid,
return -ENOKEY;
}
+/*
+ * change the request_key authorisation key on the current process
+ */
+static int keyctl_change_reqkey_auth(struct key *key)
+{
+ struct cred *new;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
+ key_put(new->request_key_auth);
+ new->request_key_auth = key_get(key);
+
+ return commit_creds(new);
+}
+
/*****************************************************************************/
/*
* instantiate the key with the specified payload, and, if one is given, link
@@ -876,12 +893,15 @@ long keyctl_instantiate_key(key_serial_t id,
size_t plen,
key_serial_t ringid)
{
+ const struct cred *cred = current_cred();
struct request_key_auth *rka;
struct key *instkey, *dest_keyring;
void *payload;
long ret;
bool vm = false;
+ kenter("%d,,%zu,%d", id, plen, ringid);
+
ret = -EINVAL;
if (plen > 1024 * 1024 - 1)
goto error;
@@ -889,7 +909,7 @@ long keyctl_instantiate_key(key_serial_t id,
/* the appropriate instantiation authorisation key must have been
* assumed before calling this */
ret = -EPERM;
- instkey = current->cred->request_key_auth;
+ instkey = cred->request_key_auth;
if (!instkey)
goto error;
@@ -931,10 +951,8 @@ long keyctl_instantiate_key(key_serial_t id,
/* discard the assumed authority if it's just been disabled by
* instantiation of the key */
- if (ret == 0) {
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = NULL;
- }
+ if (ret == 0)
+ keyctl_change_reqkey_auth(NULL);
error2:
if (!vm)
@@ -953,14 +971,17 @@ error:
*/
long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
{
+ const struct cred *cred = current_cred();
struct request_key_auth *rka;
struct key *instkey, *dest_keyring;
long ret;
+ kenter("%d,%u,%d", id, timeout, ringid);
+
/* the appropriate instantiation authorisation key must have been
* assumed before calling this */
ret = -EPERM;
- instkey = current->cred->request_key_auth;
+ instkey = cred->request_key_auth;
if (!instkey)
goto error;
@@ -982,10 +1003,8 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
/* discard the assumed authority if it's just been disabled by
* instantiation of the key */
- if (ret == 0) {
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = NULL;
- }
+ if (ret == 0)
+ keyctl_change_reqkey_auth(NULL);
error:
return ret;
@@ -999,36 +1018,56 @@ error:
*/
long keyctl_set_reqkey_keyring(int reqkey_defl)
{
- struct cred *cred = current->cred;
- int ret;
+ struct cred *new;
+ int ret, old_setting;
+
+ old_setting = current_cred_xxx(jit_keyring);
+
+ if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
+ return old_setting;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
switch (reqkey_defl) {
case KEY_REQKEY_DEFL_THREAD_KEYRING:
- ret = install_thread_keyring();
+ ret = install_thread_keyring_to_cred(new);
if (ret < 0)
- return ret;
+ goto error;
goto set;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
- ret = install_process_keyring();
- if (ret < 0)
- return ret;
+ ret = install_process_keyring_to_cred(new);
+ if (ret < 0) {
+ if (ret != -EEXIST)
+ goto error;
+ ret = 0;
+ }
+ goto set;
case KEY_REQKEY_DEFL_DEFAULT:
case KEY_REQKEY_DEFL_SESSION_KEYRING:
case KEY_REQKEY_DEFL_USER_KEYRING:
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
- set:
- cred->jit_keyring = reqkey_defl;
+ case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
+ goto set;
case KEY_REQKEY_DEFL_NO_CHANGE:
- return cred->jit_keyring;
-
case KEY_REQKEY_DEFL_GROUP_KEYRING:
default:
- return -EINVAL;
+ ret = -EINVAL;
+ goto error;
}
+set:
+ new->jit_keyring = reqkey_defl;
+ commit_creds(new);
+ return old_setting;
+error:
+ abort_creds(new);
+ return -EINVAL;
+
} /* end keyctl_set_reqkey_keyring() */
/*****************************************************************************/
@@ -1087,9 +1126,7 @@ long keyctl_assume_authority(key_serial_t id)
/* we divest ourselves of authority if given an ID of 0 */
if (id == 0) {
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = NULL;
- ret = 0;
+ ret = keyctl_change_reqkey_auth(NULL);
goto error;
}
@@ -1104,10 +1141,12 @@ long keyctl_assume_authority(key_serial_t id)
goto error;
}
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = authkey;
- ret = authkey->serial;
+ ret = keyctl_change_reqkey_auth(authkey);
+ if (ret < 0)
+ goto error;
+ key_put(authkey);
+ ret = authkey->serial;
error:
return ret;
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index fdf75f90199..ed851574d07 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -245,14 +245,14 @@ static long keyring_read(const struct key *keyring,
* allocate a keyring and link into the destination keyring
*/
struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
- struct task_struct *ctx, unsigned long flags,
+ const struct cred *cred, unsigned long flags,
struct key *dest)
{
struct key *keyring;
int ret;
keyring = key_alloc(&key_type_keyring, description,
- uid, gid, ctx,
+ uid, gid, cred,
(KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
flags);
@@ -281,7 +281,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
* - we propagate the possession attribute from the keyring ref to the key ref
*/
key_ref_t keyring_search_aux(key_ref_t keyring_ref,
- struct task_struct *context,
+ const struct cred *cred,
struct key_type *type,
const void *description,
key_match_func_t match)
@@ -304,7 +304,7 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
key_check(keyring);
/* top keyring must have search permission to begin the search */
- err = key_task_permission(keyring_ref, context, KEY_SEARCH);
+ err = key_task_permission(keyring_ref, cred, KEY_SEARCH);
if (err < 0) {
key_ref = ERR_PTR(err);
goto error;
@@ -377,7 +377,7 @@ descend:
/* key must have search permissions */
if (key_task_permission(make_key_ref(key, possessed),
- context, KEY_SEARCH) < 0)
+ cred, KEY_SEARCH) < 0)
continue;
/* we set a different error code if we pass a negative key */
@@ -404,7 +404,7 @@ ascend:
continue;
if (key_task_permission(make_key_ref(key, possessed),
- context, KEY_SEARCH) < 0)
+ cred, KEY_SEARCH) < 0)
continue;
/* stack the current position */
@@ -459,7 +459,7 @@ key_ref_t keyring_search(key_ref_t keyring,
if (!type->match)
return ERR_PTR(-ENOKEY);
- return keyring_search_aux(keyring, current,
+ return keyring_search_aux(keyring, current->cred,
type, description, type->match);
} /* end keyring_search() */
diff --git a/security/keys/permission.c b/security/keys/permission.c
index 13c36164f28..5d9fc7b93f2 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -14,24 +14,27 @@
#include "internal.h"
/*****************************************************************************/
-/*
- * check to see whether permission is granted to use a key in the desired way,
- * but permit the security modules to override
+/**
+ * key_task_permission - Check a key can be used
+ * @key_ref: The key to check
+ * @cred: The credentials to use
+ * @perm: The permissions to check for
+ *
+ * Check to see whether permission is granted to use a key in the desired way,
+ * but permit the security modules to override.
+ *
+ * The caller must hold either a ref on cred or must hold the RCU readlock or a
+ * spinlock.
*/
-int key_task_permission(const key_ref_t key_ref,
- struct task_struct *context,
+int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
key_perm_t perm)
{
- const struct cred *cred;
struct key *key;
key_perm_t kperm;
int ret;
key = key_ref_to_ptr(key_ref);
- rcu_read_lock();
- cred = __task_cred(context);
-
/* use the second 8-bits of permissions for keys the caller owns */
if (key->uid == cred->fsuid) {
kperm = key->perm >> 16;
@@ -57,7 +60,6 @@ int key_task_permission(const key_ref_t key_ref,
kperm = key->perm;
use_these_perms:
- rcu_read_lock();
/* use the top 8-bits of permissions for keys the caller possesses
* - possessor permissions are additive with other permissions
@@ -71,7 +73,7 @@ use_these_perms:
return -EACCES;
/* let LSM be the final arbiter */
- return security_key_permission(key_ref, context, perm);
+ return security_key_permission(key_ref, cred, perm);
} /* end key_task_permission() */
diff --git a/security/keys/proc.c b/security/keys/proc.c
index f619170da76..7f508def50e 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -136,8 +136,12 @@ static int proc_keys_show(struct seq_file *m, void *v)
int rc;
/* check whether the current task is allowed to view the key (assuming
- * non-possession) */
- rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW);
+ * non-possession)
+ * - the caller holds a spinlock, and thus the RCU read lock, making our
+ * access to __current_cred() safe
+ */
+ rc = key_task_permission(make_key_ref(key, 0), current_cred(),
+ KEY_VIEW);
if (rc < 0)
return 0;
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 70ee93406f3..df329f684a6 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -42,11 +42,15 @@ struct key_user root_key_user = {
*/
int install_user_keyrings(void)
{
- struct user_struct *user = current->cred->user;
+ struct user_struct *user;
+ const struct cred *cred;
struct key *uid_keyring, *session_keyring;
char buf[20];
int ret;
+ cred = current_cred();
+ user = cred->user;
+
kenter("%p{%u}", user, user->uid);
if (user->uid_keyring) {
@@ -67,7 +71,7 @@ int install_user_keyrings(void)
uid_keyring = find_keyring_by_name(buf, true);
if (IS_ERR(uid_keyring)) {
uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
- current, KEY_ALLOC_IN_QUOTA,
+ cred, KEY_ALLOC_IN_QUOTA,
NULL);
if (IS_ERR(uid_keyring)) {
ret = PTR_ERR(uid_keyring);
@@ -83,8 +87,7 @@ int install_user_keyrings(void)
if (IS_ERR(session_keyring)) {
session_keyring =
keyring_alloc(buf, user->uid, (gid_t) -1,
- current, KEY_ALLOC_IN_QUOTA,
- NULL);
+ cred, KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
goto error_release;
@@ -116,142 +119,128 @@ error:
return ret;
}
-/*****************************************************************************/
/*
- * deal with the UID changing
+ * install a fresh thread keyring directly to new credentials
*/
-void switch_uid_keyring(struct user_struct *new_user)
+int install_thread_keyring_to_cred(struct cred *new)
{
-#if 0 /* do nothing for now */
- struct key *old;
-
- /* switch to the new user's session keyring if we were running under
- * root's default session keyring */
- if (new_user->uid != 0 &&
- current->session_keyring == &root_session_keyring
- ) {
- atomic_inc(&new_user->session_keyring->usage);
-
- task_lock(current);
- old = current->session_keyring;
- current->session_keyring = new_user->session_keyring;
- task_unlock(current);
+ struct key *keyring;
- key_put(old);
- }
-#endif
+ keyring = keyring_alloc("_tid", new->uid, new->gid, new,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
-} /* end switch_uid_keyring() */
+ new->thread_keyring = keyring;
+ return 0;
+}
-/*****************************************************************************/
/*
* install a fresh thread keyring, discarding the old one
*/
-int install_thread_keyring(void)
+static int install_thread_keyring(void)
{
- struct task_struct *tsk = current;
- struct key *keyring, *old;
- char buf[20];
+ struct cred *new;
int ret;
- sprintf(buf, "_tid.%u", tsk->pid);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk,
- KEY_ALLOC_QUOTA_OVERRUN, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
+ BUG_ON(new->thread_keyring);
+
+ ret = install_thread_keyring_to_cred(new);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
}
- task_lock(tsk);
- old = tsk->cred->thread_keyring;
- tsk->cred->thread_keyring = keyring;
- task_unlock(tsk);
+ return commit_creds(new);
+}
- ret = 0;
+/*
+ * install a process keyring directly to a credentials struct
+ * - returns -EEXIST if there was already a process keyring, 0 if one installed,
+ * and other -ve on any other error
+ */
+int install_process_keyring_to_cred(struct cred *new)
+{
+ struct key *keyring;
+ int ret;
- key_put(old);
-error:
+ if (new->tgcred->process_keyring)
+ return -EEXIST;
+
+ keyring = keyring_alloc("_pid", new->uid, new->gid,
+ new, KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
+
+ spin_lock_irq(&new->tgcred->lock);
+ if (!new->tgcred->process_keyring) {
+ new->tgcred->process_keyring = keyring;
+ keyring = NULL;
+ ret = 0;
+ } else {
+ ret = -EEXIST;
+ }
+ spin_unlock_irq(&new->tgcred->lock);
+ key_put(keyring);
return ret;
+}
-} /* end install_thread_keyring() */
-
-/*****************************************************************************/
/*
* make sure a process keyring is installed
+ * - we
*/
-int install_process_keyring(void)
+static int install_process_keyring(void)
{
- struct task_struct *tsk = current;
- struct key *keyring;
- char buf[20];
+ struct cred *new;
int ret;
- might_sleep();
-
- if (!tsk->cred->tgcred->process_keyring) {
- sprintf(buf, "_pid.%u", tsk->tgid);
-
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk,
- KEY_ALLOC_QUOTA_OVERRUN, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
- }
-
- /* attach keyring */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- if (!tsk->cred->tgcred->process_keyring) {
- tsk->cred->tgcred->process_keyring = keyring;
- keyring = NULL;
- }
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- key_put(keyring);
+ ret = install_process_keyring_to_cred(new);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret != -EEXIST ?: 0;
}
- ret = 0;
-error:
- return ret;
-
-} /* end install_process_keyring() */
+ return commit_creds(new);
+}
-/*****************************************************************************/
/*
- * install a session keyring, discarding the old one
- * - if a keyring is not supplied, an empty one is invented
+ * install a session keyring directly to a credentials struct
*/
-static int install_session_keyring(struct key *keyring)
+static int install_session_keyring_to_cred(struct cred *cred,
+ struct key *keyring)
{
- struct task_struct *tsk = current;
unsigned long flags;
struct key *old;
- char buf[20];
might_sleep();
/* create an empty session keyring */
if (!keyring) {
- sprintf(buf, "_ses.%u", tsk->tgid);
-
flags = KEY_ALLOC_QUOTA_OVERRUN;
- if (tsk->cred->tgcred->session_keyring)
+ if (cred->tgcred->session_keyring)
flags = KEY_ALLOC_IN_QUOTA;
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid,
- tsk, flags, NULL);
+ keyring = keyring_alloc("_ses", cred->uid, cred->gid,
+ cred, flags, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
- }
- else {
+ } else {
atomic_inc(&keyring->usage);
}
/* install the keyring */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- old = tsk->cred->tgcred->session_keyring;
- rcu_assign_pointer(tsk->cred->tgcred->session_keyring, keyring);
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ spin_lock_irq(&cred->tgcred->lock);
+ old = cred->tgcred->session_keyring;
+ rcu_assign_pointer(cred->tgcred->session_keyring, keyring);
+ spin_unlock_irq(&cred->tgcred->lock);
/* we're using RCU on the pointer, but there's no point synchronising
* on it if it didn't previously point to anything */
@@ -261,38 +250,29 @@ static int install_session_keyring(struct key *keyring)
}
return 0;
+}
-} /* end install_session_keyring() */
-
-/*****************************************************************************/
/*
- * copy the keys for fork
+ * install a session keyring, discarding the old one
+ * - if a keyring is not supplied, an empty one is invented
*/
-int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
+static int install_session_keyring(struct key *keyring)
{
- key_check(tsk->cred->thread_keyring);
- key_check(tsk->cred->request_key_auth);
-
- /* no thread keyring yet */
- tsk->cred->thread_keyring = NULL;
-
- /* copy the request_key() authorisation for this thread */
- key_get(tsk->cred->request_key_auth);
-
- return 0;
+ struct cred *new;
+ int ret;
-} /* end copy_keys() */
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
-/*****************************************************************************/
-/*
- * dispose of per-thread keys upon thread exit
- */
-void exit_keys(struct task_struct *tsk)
-{
- key_put(tsk->cred->thread_keyring);
- key_put(tsk->cred->request_key_auth);
+ ret = install_session_keyring_to_cred(new, NULL);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
+ }
-} /* end exit_keys() */
+ return commit_creds(new);
+}
/*****************************************************************************/
/*
@@ -300,38 +280,41 @@ void exit_keys(struct task_struct *tsk)
*/
int exec_keys(struct task_struct *tsk)
{
- struct key *old;
+ struct thread_group_cred *tgcred = NULL;
+ struct cred *new;
- /* newly exec'd tasks don't get a thread keyring */
- task_lock(tsk);
- old = tsk->cred->thread_keyring;
- tsk->cred->thread_keyring = NULL;
- task_unlock(tsk);
+#ifdef CONFIG_KEYS
+ tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL);
+ if (!tgcred)
+ return -ENOMEM;
+#endif
- key_put(old);
+ new = prepare_creds();
+ if (new < 0)
+ return -ENOMEM;
- /* discard the process keyring from a newly exec'd task */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- old = tsk->cred->tgcred->process_keyring;
- tsk->cred->tgcred->process_keyring = NULL;
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ /* newly exec'd tasks don't get a thread keyring */
+ key_put(new->thread_keyring);
+ new->thread_keyring = NULL;
- key_put(old);
+ /* create a new per-thread-group creds for all this set of threads to
+ * share */
+ memcpy(tgcred, new->tgcred, sizeof(struct thread_group_cred));
- return 0;
+ atomic_set(&tgcred->usage, 1);
+ spin_lock_init(&tgcred->lock);
-} /* end exec_keys() */
+ /* inherit the session keyring; new process keyring */
+ key_get(tgcred->session_keyring);
+ tgcred->process_keyring = NULL;
-/*****************************************************************************/
-/*
- * deal with SUID programs
- * - we might want to make this invent a new session keyring
- */
-int suid_keys(struct task_struct *tsk)
-{
+ release_tgcred(new);
+ new->tgcred = tgcred;
+
+ commit_creds(new);
return 0;
-} /* end suid_keys() */
+} /* end exec_keys() */
/*****************************************************************************/
/*
@@ -376,16 +359,13 @@ void key_fsgid_changed(struct task_struct *tsk)
key_ref_t search_process_keyrings(struct key_type *type,
const void *description,
key_match_func_t match,
- struct task_struct *context)
+ const struct cred *cred)
{
struct request_key_auth *rka;
- struct cred *cred;
key_ref_t key_ref, ret, err;
might_sleep();
- cred = get_task_cred(context);
-
/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
* searchable, but we failed to find a key or we found a negative key;
* otherwise we want to return a sample error (probably -EACCES) if
@@ -401,7 +381,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
if (cred->thread_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->thread_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
@@ -422,7 +402,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
if (cred->tgcred->process_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->tgcred->process_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
@@ -446,7 +426,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
make_key_ref(rcu_dereference(
cred->tgcred->session_keyring),
1),
- context, type, description, match);
+ cred, type, description, match);
rcu_read_unlock();
if (!IS_ERR(key_ref))
@@ -468,7 +448,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
else if (cred->user->session_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->user->session_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
@@ -490,7 +470,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
* - we don't permit access to request_key auth keys via this method
*/
if (cred->request_key_auth &&
- context == current &&
+ cred == current_cred() &&
type != &key_type_request_key_auth
) {
/* defend against the auth key being revoked */
@@ -500,7 +480,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
rka = cred->request_key_auth->payload.data;
key_ref = search_process_keyrings(type, description,
- match, rka->context);
+ match, rka->cred);
up_read(&cred->request_key_auth->sem);
@@ -527,7 +507,6 @@ key_ref_t search_process_keyrings(struct key_type *type,
key_ref = ret ? ret : err;
found:
- put_cred(cred);
return key_ref;
} /* end search_process_keyrings() */
@@ -552,8 +531,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
key_perm_t perm)
{
struct request_key_auth *rka;
- struct task_struct *t = current;
- struct cred *cred;
+ const struct cred *cred;
struct key *key;
key_ref_t key_ref, skey_ref;
int ret;
@@ -608,6 +586,7 @@ try_again:
goto error;
ret = install_session_keyring(
cred->user->session_keyring);
+
if (ret < 0)
goto error;
goto reget_creds;
@@ -693,7 +672,7 @@ try_again:
/* check to see if we possess the key */
skey_ref = search_process_keyrings(key->type, key,
lookup_user_key_possessed,
- current);
+ cred);
if (!IS_ERR(skey_ref)) {
key_put(key);
@@ -725,7 +704,7 @@ try_again:
goto invalid_key;
/* check the permissions */
- ret = key_task_permission(key_ref, t, perm);
+ ret = key_task_permission(key_ref, cred, perm);
if (ret < 0)
goto invalid_key;
@@ -755,21 +734,33 @@ reget_creds:
*/
long join_session_keyring(const char *name)
{
- struct task_struct *tsk = current;
- struct cred *cred = current->cred;
+ const struct cred *old;
+ struct cred *new;
struct key *keyring;
- long ret;
+ long ret, serial;
+
+ /* only permit this if there's a single thread in the thread group -
+ * this avoids us having to adjust the creds on all threads and risking
+ * ENOMEM */
+ if (!is_single_threaded(current))
+ return -EMLINK;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+ old = current_cred();
/* if no name is provided, install an anonymous keyring */
if (!name) {
- ret = install_session_keyring(NULL);
+ ret = install_session_keyring_to_cred(new, NULL);
if (ret < 0)
goto error;
- rcu_read_lock();
- ret = rcu_dereference(cred->tgcred->session_keyring)->serial;
- rcu_read_unlock();
- goto error;
+ serial = new->tgcred->session_keyring->serial;
+ ret = commit_creds(new);
+ if (ret == 0)
+ ret = serial;
+ goto okay;
}
/* allow the user to join or create a named keyring */
@@ -779,29 +770,33 @@ long join_session_keyring(const char *name)
keyring = find_keyring_by_name(name, false);
if (PTR_ERR(keyring) == -ENOKEY) {
/* not found - try and create a new one */
- keyring = keyring_alloc(name, cred->uid, cred->gid, tsk,
+ keyring = keyring_alloc(name, old->uid, old->gid, old,
KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
}
- }
- else if (IS_ERR(keyring)) {
+ } else if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
}
/* we've got a keyring - now to install it */
- ret = install_session_keyring(keyring);
+ ret = install_session_keyring_to_cred(new, keyring);
if (ret < 0)
goto error2;
+ commit_creds(new);
+ mutex_unlock(&key_session_mutex);
+
ret = keyring->serial;
key_put(keyring);
+okay:
+ return ret;
error2:
mutex_unlock(&key_session_mutex);
error:
+ abort_creds(new);
return ret;
-
-} /* end join_session_keyring() */
+}
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 3d12558362d..0e04f72ef2d 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -83,8 +83,10 @@ static int call_sbin_request_key(struct key_construction *cons,
/* allocate a new session keyring */
sprintf(desc, "_req.%u", key->serial);
- keyring = keyring_alloc(desc, current_fsuid(), current_fsgid(), current,
+ cred = get_current_cred();
+ keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ put_cred(cred);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error_alloc;
@@ -104,8 +106,7 @@ static int call_sbin_request_key(struct key_construction *cons,
/* we specify the process's default keyrings */
sprintf(keyring_str[0], "%d",
- cred->thread_keyring ?
- cred->thread_keyring->serial : 0);
+ cred->thread_keyring ? cred->thread_keyring->serial : 0);
prkey = 0;
if (cred->tgcred->process_keyring)
@@ -155,8 +156,8 @@ error_link:
key_put(keyring);
error_alloc:
- kleave(" = %d", ret);
complete_request_key(cons, ret);
+ kleave(" = %d", ret);
return ret;
}
@@ -295,6 +296,7 @@ static int construct_alloc_key(struct key_type *type,
struct key_user *user,
struct key **_key)
{
+ const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
@@ -302,9 +304,8 @@ static int construct_alloc_key(struct key_type *type,
mutex_lock(&user->cons_lock);
- key = key_alloc(type, description,
- current_fsuid(), current_fsgid(), current, KEY_POS_ALL,
- flags);
+ key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred,
+ KEY_POS_ALL, flags);
if (IS_ERR(key))
goto alloc_failed;
@@ -317,8 +318,7 @@ static int construct_alloc_key(struct key_type *type,
* waited for locks */
mutex_lock(&key_construction_mutex);
- key_ref = search_process_keyrings(type, description, type->match,
- current);
+ key_ref = search_process_keyrings(type, description, type->match, cred);
if (!IS_ERR(key_ref))
goto key_already_present;
@@ -363,6 +363,8 @@ static struct key *construct_key_and_link(struct key_type *type,
struct key *key;
int ret;
+ kenter("");
+
user = key_user_lookup(current_fsuid());
if (!user)
return ERR_PTR(-ENOMEM);
@@ -376,17 +378,21 @@ static struct key *construct_key_and_link(struct key_type *type,
if (ret == 0) {
ret = construct_key(key, callout_info, callout_len, aux,
dest_keyring);
- if (ret < 0)
+ if (ret < 0) {
+ kdebug("cons failed");
goto construction_failed;
+ }
}
key_put(dest_keyring);
+ kleave(" = key %d", key_serial(key));
return key;
construction_failed:
key_negate_and_link(key, key_negative_timeout, NULL, NULL);
key_put(key);
key_put(dest_keyring);
+ kleave(" = %d", ret);
return ERR_PTR(ret);
}
@@ -405,6 +411,7 @@ struct key *request_key_and_link(struct key_type *type,
struct key *dest_keyring,
unsigned long flags)
{
+ const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
@@ -414,7 +421,7 @@ struct key *request_key_and_link(struct key_type *type,
/* search all the process keyrings for a key */
key_ref = search_process_keyrings(type, description, type->match,
- current);
+ cred);
if (!IS_ERR(key_ref)) {
key = key_ref_to_ptr(key_ref);
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 2125579d5d7..86747151ee5 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -105,9 +105,9 @@ static void request_key_auth_revoke(struct key *key)
kenter("{%d}", key->serial);
- if (rka->context) {
- put_task_struct(rka->context);
- rka->context = NULL;
+ if (rka->cred) {
+ put_cred(rka->cred);
+ rka->cred = NULL;
}
} /* end request_key_auth_revoke() */
@@ -122,9 +122,9 @@ static void request_key_auth_destroy(struct key *key)
kenter("{%d}", key->serial);
- if (rka->context) {
- put_task_struct(rka->context);
- rka->context = NULL;
+ if (rka->cred) {
+ put_cred(rka->cred);
+ rka->cred = NULL;
}
key_put(rka->target_key);
@@ -143,6 +143,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,
size_t callout_len, struct key *dest_keyring)
{
struct request_key_auth *rka, *irka;
+ const struct cred *cred = current->cred;
struct key *authkey = NULL;
char desc[20];
int ret;
@@ -164,28 +165,25 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,
/* see if the calling process is already servicing the key request of
* another process */
- if (current->cred->request_key_auth) {
+ if (cred->request_key_auth) {
/* it is - use that instantiation context here too */
- down_read(&current->cred->request_key_auth->sem);
+ down_read(&cred->request_key_auth->sem);
/* if the auth key has been revoked, then the key we're
* servicing is already instantiated */
- if (test_bit(KEY_FLAG_REVOKED,
- &current->cred->request_key_auth->flags))
+ if (test_bit(KEY_FLAG_REVOKED, &cred->request_key_auth->flags))
goto auth_key_revoked;
- irka = current->cred->request_key_auth->payload.data;
- rka->context = irka->context;
+ irka = cred->request_key_auth->payload.data;
+ rka->cred = get_cred(irka->cred);
rka->pid = irka->pid;
- get_task_struct(rka->context);
- up_read(&current->cred->request_key_auth->sem);
+ up_read(&cred->request_key_auth->sem);
}
else {
/* it isn't - use this process as the context */
- rka->context = current;
+ rka->cred = get_cred(cred);
rka->pid = current->pid;
- get_task_struct(rka->context);
}
rka->target_key = key_get(target);
@@ -197,7 +195,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,
sprintf(desc, "%x", target->serial);
authkey = key_alloc(&key_type_request_key_auth, desc,
- current_fsuid(), current_fsgid(), current,
+ cred->fsuid, cred->fsgid, cred,
KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA);
if (IS_ERR(authkey)) {
@@ -205,16 +203,16 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,
goto error_alloc;
}
- /* construct and attach to the keyring */
+ /* construct the auth key */
ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL);
if (ret < 0)
goto error_inst;
- kleave(" = {%d}", authkey->serial);
+ kleave(" = {%d,%d}", authkey->serial, atomic_read(&authkey->usage));
return authkey;
auth_key_revoked:
- up_read(&current->cred->request_key_auth->sem);
+ up_read(&cred->request_key_auth->sem);
kfree(rka->callout_info);
kfree(rka);
kleave("= -EKEYREVOKED");
@@ -257,6 +255,7 @@ static int key_get_instantiation_authkey_match(const struct key *key,
*/
struct key *key_get_instantiation_authkey(key_serial_t target_id)
{
+ const struct cred *cred = current_cred();
struct key *authkey;
key_ref_t authkey_ref;
@@ -264,7 +263,7 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id)
&key_type_request_key_auth,
(void *) (unsigned long) target_id,
key_get_instantiation_authkey_match,
- current);
+ cred);
if (IS_ERR(authkey_ref)) {
authkey = ERR_CAST(authkey_ref);
diff --git a/security/security.c b/security/security.c
index f40a0a04c3c..a55d739c686 100644
--- a/security/security.c
+++ b/security/security.c
@@ -145,18 +145,13 @@ int security_capget(struct task_struct *target,
return security_ops->capget(target, effective, inheritable, permitted);
}
-int security_capset_check(const kernel_cap_t *effective,
- const kernel_cap_t *inheritable,
- const kernel_cap_t *permitted)
+int security_capset(struct cred *new, const struct cred *old,
+ const kernel_cap_t *effective,
+ const kernel_cap_t *inheritable,
+ const kernel_cap_t *permitted)
{
- return security_ops->capset_check(effective, inheritable, permitted);
-}
-
-void security_capset_set(const kernel_cap_t *effective,
- const kernel_cap_t *inheritable,
- const kernel_cap_t *permitted)
-{
- security_ops->capset_set(effective, inheritable, permitted);
+ return security_ops->capset(new, old,
+ effective, inheritable, permitted);
}
int security_capable(struct task_struct *tsk, int cap)
@@ -228,9 +223,9 @@ void security_bprm_free(struct linux_binprm *bprm)
security_ops->bprm_free_security(bprm);
}
-void security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
+int security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
{
- security_ops->bprm_apply_creds(bprm, unsafe);
+ return security_ops->bprm_apply_creds(bprm, unsafe);
}
void security_bprm_post_apply_creds(struct linux_binprm *bprm)
@@ -616,14 +611,19 @@ int security_task_create(unsigned long clone_flags)
return security_ops->task_create(clone_flags);
}
-int security_cred_alloc(struct cred *cred)
+void security_cred_free(struct cred *cred)
{
- return security_ops->cred_alloc_security(cred);
+ security_ops->cred_free(cred);
}
-void security_cred_free(struct cred *cred)
+int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp)
{
- security_ops->cred_free(cred);
+ return security_ops->cred_prepare(new, old, gfp);
+}
+
+void security_commit_creds(struct cred *new, const struct cred *old)
+{
+ return security_ops->cred_commit(new, old);
}
int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
@@ -631,10 +631,10 @@ int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
return security_ops->task_setuid(id0, id1, id2, flags);
}
-int security_task_post_setuid(uid_t old_ruid, uid_t old_euid,
- uid_t old_suid, int flags)
+int security_task_fix_setuid(struct cred *new, const struct cred *old,
+ int flags)
{
- return security_ops->task_post_setuid(old_ruid, old_euid, old_suid, flags);
+ return security_ops->task_fix_setuid(new, old, flags);
}
int security_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags)
@@ -716,14 +716,9 @@ int security_task_wait(struct task_struct *p)
}
int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
- unsigned long arg4, unsigned long arg5, long *rc_p)
-{
- return security_ops->task_prctl(option, arg2, arg3, arg4, arg5, rc_p);
-}
-
-void security_task_reparent_to_init(struct task_struct *p)
+ unsigned long arg4, unsigned long arg5)
{
- security_ops->task_reparent_to_init(p);
+ return security_ops->task_prctl(option, arg2, arg3, arg4, arg5);
}
void security_task_to_inode(struct task_struct *p, struct inode *inode)
@@ -1123,9 +1118,10 @@ EXPORT_SYMBOL(security_skb_classify_flow);
#ifdef CONFIG_KEYS
-int security_key_alloc(struct key *key, struct task_struct *tsk, unsigned long flags)
+int security_key_alloc(struct key *key, const struct cred *cred,
+ unsigned long flags)
{
- return security_ops->key_alloc(key, tsk, flags);
+ return security_ops->key_alloc(key, cred, flags);
}
void security_key_free(struct key *key)
@@ -1134,9 +1130,9 @@ void security_key_free(struct key *key)
}
int security_key_permission(key_ref_t key_ref,
- struct task_struct *context, key_perm_t perm)
+ const struct cred *cred, key_perm_t perm)
{
- return security_ops->key_permission(key_ref, context, perm);
+ return security_ops->key_permission(key_ref, cred, perm);
}
int security_key_getsecurity(struct key *key, char **_buffer)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f20cbd681ba..c71bba78872 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -156,20 +156,20 @@ static int selinux_secmark_enabled(void)
return (atomic_read(&selinux_secmark_refcount) > 0);
}
-/* Allocate and free functions for each kind of security blob. */
-
-static int cred_alloc_security(struct cred *cred)
+/*
+ * initialise the security for the init task
+ */
+static void cred_init_security(void)
{
+ struct cred *cred = (struct cred *) current->cred;
struct task_security_struct *tsec;
tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
if (!tsec)
- return -ENOMEM;
+ panic("SELinux: Failed to initialize initial task.\n");
- tsec->osid = tsec->sid = SECINITSID_UNLABELED;
+ tsec->osid = tsec->sid = SECINITSID_KERNEL;
cred->security = tsec;
-
- return 0;
}
/*
@@ -1379,6 +1379,19 @@ static inline u32 signal_to_av(int sig)
}
/*
+ * Check permission between a pair of credentials
+ * fork check, ptrace check, etc.
+ */
+static int cred_has_perm(const struct cred *actor,
+ const struct cred *target,
+ u32 perms)
+{
+ u32 asid = cred_sid(actor), tsid = cred_sid(target);
+
+ return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
+}
+
+/*
* Check permission between a pair of tasks, e.g. signal checks,
* fork check, ptrace check, etc.
* tsk1 is the actor and tsk2 is the target
@@ -1820,24 +1833,19 @@ static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
return secondary_ops->capget(target, effective, inheritable, permitted);
}
-static int selinux_capset_check(const kernel_cap_t *effective,
- const kernel_cap_t *inheritable,
- const kernel_cap_t *permitted)
+static int selinux_capset(struct cred *new, const struct cred *old,
+ const kernel_cap_t *effective,
+ const kernel_cap_t *inheritable,
+ const kernel_cap_t *permitted)
{
int error;
- error = secondary_ops->capset_check(effective, inheritable, permitted);
+ error = secondary_ops->capset(new, old,
+ effective, inheritable, permitted);
if (error)
return error;
- return task_has_perm(current, current, PROCESS__SETCAP);
-}
-
-static void selinux_capset_set(const kernel_cap_t *effective,
- const kernel_cap_t *inheritable,
- const kernel_cap_t *permitted)
-{
- secondary_ops->capset_set(effective, inheritable, permitted);
+ return cred_has_perm(old, new, PROCESS__SETCAP);
}
static int selinux_capable(struct task_struct *tsk, int cap, int audit)
@@ -2244,16 +2252,23 @@ static inline void flush_unauthorized_files(const struct cred *cred,
spin_unlock(&files->file_lock);
}
-static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
+static int selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
{
struct task_security_struct *tsec;
struct bprm_security_struct *bsec;
+ struct cred *new;
u32 sid;
int rc;
- secondary_ops->bprm_apply_creds(bprm, unsafe);
+ rc = secondary_ops->bprm_apply_creds(bprm, unsafe);
+ if (rc < 0)
+ return rc;
- tsec = current_security();
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
+ tsec = new->security;
bsec = bprm->security;
sid = bsec->sid;
@@ -2268,7 +2283,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
PROCESS__SHARE, NULL);
if (rc) {
bsec->unsafe = 1;
- return;
+ goto out;
}
}
@@ -2292,12 +2307,16 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
PROCESS__PTRACE, NULL);
if (rc) {
bsec->unsafe = 1;
- return;
+ goto out;
}
}
}
tsec->sid = sid;
}
+
+out:
+ commit_creds(new);
+ return 0;
}
/*
@@ -3021,6 +3040,7 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd,
static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
const struct cred *cred = current_cred();
+ int rc = 0;
#ifndef CONFIG_PPC32
if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
@@ -3029,9 +3049,9 @@ static int file_map_prot_check(struct file *file, unsigned long prot, int shared
* private file mapping that will also be writable.
* This has an additional check.
*/
- int rc = task_has_perm(current, current, PROCESS__EXECMEM);
+ rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
if (rc)
- return rc;
+ goto error;
}
#endif
@@ -3048,7 +3068,9 @@ static int file_map_prot_check(struct file *file, unsigned long prot, int shared
return file_has_perm(cred, file, av);
}
- return 0;
+
+error:
+ return rc;
}
static int selinux_file_mmap(struct file *file, unsigned long reqprot,
@@ -3090,8 +3112,7 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
rc = 0;
if (vma->vm_start >= vma->vm_mm->start_brk &&
vma->vm_end <= vma->vm_mm->brk) {
- rc = task_has_perm(current, current,
- PROCESS__EXECHEAP);
+ rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
} else if (!vma->vm_file &&
vma->vm_start <= vma->vm_mm->start_stack &&
vma->vm_end >= vma->vm_mm->start_stack) {
@@ -3104,8 +3125,7 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
* modified content. This typically should only
* occur for text relocations.
*/
- rc = file_has_perm(cred, vma->vm_file,
- FILE__EXECMOD);
+ rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
}
if (rc)
return rc;
@@ -3211,6 +3231,7 @@ static int selinux_dentry_open(struct file *file, const struct cred *cred)
struct file_security_struct *fsec;
struct inode *inode;
struct inode_security_struct *isec;
+
inode = file->f_path.dentry->d_inode;
fsec = file->f_security;
isec = inode->i_security;
@@ -3247,38 +3268,41 @@ static int selinux_task_create(unsigned long clone_flags)
return task_has_perm(current, current, PROCESS__FORK);
}
-static int selinux_cred_alloc_security(struct cred *cred)
+/*
+ * detach and free the LSM part of a set of credentials
+ */
+static void selinux_cred_free(struct cred *cred)
{
- struct task_security_struct *tsec1, *tsec2;
- int rc;
-
- tsec1 = current_security();
+ struct task_security_struct *tsec = cred->security;
+ cred->security = NULL;
+ kfree(tsec);
+}
- rc = cred_alloc_security(cred);
- if (rc)
- return rc;
- tsec2 = cred->security;
+/*
+ * prepare a new set of credentials for modification
+ */
+static int selinux_cred_prepare(struct cred *new, const struct cred *old,
+ gfp_t gfp)
+{
+ const struct task_security_struct *old_tsec;
+ struct task_security_struct *tsec;
- tsec2->osid = tsec1->osid;
- tsec2->sid = tsec1->sid;
+ old_tsec = old->security;
- /* Retain the exec, fs, key, and sock SIDs across fork */
- tsec2->exec_sid = tsec1->exec_sid;
- tsec2->create_sid = tsec1->create_sid;
- tsec2->keycreate_sid = tsec1->keycreate_sid;
- tsec2->sockcreate_sid = tsec1->sockcreate_sid;
+ tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
+ if (!tsec)
+ return -ENOMEM;
+ new->security = tsec;
return 0;
}
/*
- * detach and free the LSM part of a set of credentials
+ * commit new credentials
*/
-static void selinux_cred_free(struct cred *cred)
+static void selinux_cred_commit(struct cred *new, const struct cred *old)
{
- struct task_security_struct *tsec = cred->security;
- cred->security = NULL;
- kfree(tsec);
+ secondary_ops->cred_commit(new, old);
}
static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
@@ -3292,9 +3316,10 @@ static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
return 0;
}
-static int selinux_task_post_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
+static int selinux_task_fix_setuid(struct cred *new, const struct cred *old,
+ int flags)
{
- return secondary_ops->task_post_setuid(id0, id1, id2, flags);
+ return secondary_ops->task_fix_setuid(new, old, flags);
}
static int selinux_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags)
@@ -3368,7 +3393,7 @@ static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim
/* Control the ability to change the hard limit (whether
lowering or raising it), so that the hard limit can
later be used as a safe reset point for the soft limit
- upon context transitions. See selinux_bprm_apply_creds. */
+ upon context transitions. See selinux_bprm_committing_creds. */
if (old_rlim->rlim_max != new_rlim->rlim_max)
return task_has_perm(current, current, PROCESS__SETRLIMIT);
@@ -3422,13 +3447,12 @@ static int selinux_task_prctl(int option,
unsigned long arg2,
unsigned long arg3,
unsigned long arg4,
- unsigned long arg5,
- long *rc_p)
+ unsigned long arg5)
{
/* The current prctl operations do not appear to require
any SELinux controls since they merely observe or modify
the state of the current process. */
- return secondary_ops->task_prctl(option, arg2, arg3, arg4, arg5, rc_p);
+ return secondary_ops->task_prctl(option, arg2, arg3, arg4, arg5);
}
static int selinux_task_wait(struct task_struct *p)
@@ -3436,18 +3460,6 @@ static int selinux_task_wait(struct task_struct *p)
return task_has_perm(p, current, PROCESS__SIGCHLD);
}
-static void selinux_task_reparent_to_init(struct task_struct *p)
-{
- struct task_security_struct *tsec;
-
- secondary_ops->task_reparent_to_init(p);
-
- tsec = p->cred->security;
- tsec->osid = tsec->sid;
- tsec->sid = SECINITSID_KERNEL;
- return;
-}
-
static void selinux_task_to_inode(struct task_struct *p,
struct inode *inode)
{
@@ -5325,7 +5337,8 @@ static int selinux_setprocattr(struct task_struct *p,
{
struct task_security_struct *tsec;
struct task_struct *tracer;
- u32 sid = 0;
+ struct cred *new;
+ u32 sid = 0, ptsid;
int error;
char *str = value;
@@ -5372,86 +5385,75 @@ static int selinux_setprocattr(struct task_struct *p,
return error;
}
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
/* Permission checking based on the specified context is
performed during the actual operation (execve,
open/mkdir/...), when we know the full context of the
- operation. See selinux_bprm_set_security for the execve
+ operation. See selinux_bprm_set_creds for the execve
checks and may_create for the file creation checks. The
operation will then fail if the context is not permitted. */
- tsec = p->cred->security;
- if (!strcmp(name, "exec"))
+ tsec = new->security;
+ if (!strcmp(name, "exec")) {
tsec->exec_sid = sid;
- else if (!strcmp(name, "fscreate"))
+ } else if (!strcmp(name, "fscreate")) {
tsec->create_sid = sid;
- else if (!strcmp(name, "keycreate")) {
+ } else if (!strcmp(name, "keycreate")) {
error = may_create_key(sid, p);
if (error)
- return error;
+ goto abort_change;
tsec->keycreate_sid = sid;
- } else if (!strcmp(name, "sockcreate"))
+ } else if (!strcmp(name, "sockcreate")) {
tsec->sockcreate_sid = sid;
- else if (!strcmp(name, "current")) {
- struct av_decision avd;
-
+ } else if (!strcmp(name, "current")) {
+ error = -EINVAL;
if (sid == 0)
- return -EINVAL;
- /*
- * SELinux allows to change context in the following case only.
- * - Single threaded processes.
- * - Multi threaded processes intend to change its context into
- * more restricted domain (defined by TYPEBOUNDS statement).
- */
- if (atomic_read(&p->mm->mm_users) != 1) {
- struct task_struct *g, *t;
- struct mm_struct *mm = p->mm;
- read_lock(&tasklist_lock);
- do_each_thread(g, t) {
- if (t->mm == mm && t != p) {
- read_unlock(&tasklist_lock);
- error = security_bounded_transition(tsec->sid, sid);
- if (!error)
- goto boundary_ok;
-
- return error;
- }
- } while_each_thread(g, t);
- read_unlock(&tasklist_lock);
+ goto abort_change;
+
+ /* Only allow single threaded processes to change context */
+ error = -EPERM;
+ if (!is_single_threaded(p)) {
+ error = security_bounded_transition(tsec->sid, sid);
+ if (error)
+ goto abort_change;
}
-boundary_ok:
/* Check permissions for the transition. */
error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
PROCESS__DYNTRANSITION, NULL);
if (error)
- return error;
+ goto abort_change;
/* Check for ptracing, and update the task SID if ok.
Otherwise, leave SID unchanged and fail. */
+ ptsid = 0;
task_lock(p);
- rcu_read_lock();
tracer = tracehook_tracer_task(p);
- if (tracer != NULL) {
- u32 ptsid = task_sid(tracer);
- rcu_read_unlock();
- error = avc_has_perm_noaudit(ptsid, sid,
- SECCLASS_PROCESS,
- PROCESS__PTRACE, 0, &avd);
- if (!error)
- tsec->sid = sid;
- task_unlock(p);
- avc_audit(ptsid, sid, SECCLASS_PROCESS,
- PROCESS__PTRACE, &avd, error, NULL);
+ if (tracer)
+ ptsid = task_sid(tracer);
+ task_unlock(p);
+
+ if (tracer) {
+ error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
+ PROCESS__PTRACE, NULL);
if (error)
- return error;
- } else {
- rcu_read_unlock();
- tsec->sid = sid;
- task_unlock(p);
+ goto abort_change;
}
- } else
- return -EINVAL;
+ tsec->sid = sid;
+ } else {
+ error = -EINVAL;
+ goto abort_change;
+ }
+
+ commit_creds(new);
return size;
+
+abort_change:
+ abort_creds(new);
+ return error;
}
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
@@ -5471,23 +5473,21 @@ static void selinux_release_secctx(char *secdata, u32 seclen)
#ifdef CONFIG_KEYS
-static int selinux_key_alloc(struct key *k, struct task_struct *tsk,
+static int selinux_key_alloc(struct key *k, const struct cred *cred,
unsigned long flags)
{
- const struct task_security_struct *__tsec;
+ const struct task_security_struct *tsec;
struct key_security_struct *ksec;
ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
if (!ksec)
return -ENOMEM;
- rcu_read_lock();
- __tsec = __task_cred(tsk)->security;
- if (__tsec->keycreate_sid)
- ksec->sid = __tsec->keycreate_sid;
+ tsec = cred->security;
+ if (tsec->keycreate_sid)
+ ksec->sid = tsec->keycreate_sid;
else
- ksec->sid = __tsec->sid;
- rcu_read_unlock();
+ ksec->sid = tsec->sid;
k->security = ksec;
return 0;
@@ -5502,8 +5502,8 @@ static void selinux_key_free(struct key *k)
}
static int selinux_key_permission(key_ref_t key_ref,
- struct task_struct *ctx,
- key_perm_t perm)
+ const struct cred *cred,
+ key_perm_t perm)
{
struct key *key;
struct key_security_struct *ksec;
@@ -5515,7 +5515,7 @@ static int selinux_key_permission(key_ref_t key_ref,
if (perm == 0)
return 0;
- sid = task_sid(ctx);
+ sid = cred_sid(cred);
key = key_ref_to_ptr(key_ref);
ksec = key->security;
@@ -5545,8 +5545,7 @@ static struct security_operations selinux_ops = {
.ptrace_may_access = selinux_ptrace_may_access,
.ptrace_traceme = selinux_ptrace_traceme,
.capget = selinux_capget,
- .capset_check = selinux_capset_check,
- .capset_set = selinux_capset_set,
+ .capset = selinux_capset,
.sysctl = selinux_sysctl,
.capable = selinux_capable,
.quotactl = selinux_quotactl,
@@ -5621,10 +5620,11 @@ static struct security_operations selinux_ops = {
.dentry_open = selinux_dentry_open,
.task_create = selinux_task_create,
- .cred_alloc_security = selinux_cred_alloc_security,
.cred_free = selinux_cred_free,
+ .cred_prepare = selinux_cred_prepare,
+ .cred_commit = selinux_cred_commit,
.task_setuid = selinux_task_setuid,
- .task_post_setuid = selinux_task_post_setuid,
+ .task_fix_setuid = selinux_task_fix_setuid,
.task_setgid = selinux_task_setgid,
.task_setpgid = selinux_task_setpgid,
.task_getpgid = selinux_task_getpgid,
@@ -5641,7 +5641,6 @@ static struct security_operations selinux_ops = {
.task_kill = selinux_task_kill,
.task_wait = selinux_task_wait,
.task_prctl = selinux_task_prctl,
- .task_reparent_to_init = selinux_task_reparent_to_init,
.task_to_inode = selinux_task_to_inode,
.ipc_permission = selinux_ipc_permission,
@@ -5737,8 +5736,6 @@ static struct security_operations selinux_ops = {
static __init int selinux_init(void)
{
- struct task_security_struct *tsec;
-
if (!security_module_enable(&selinux_ops)) {
selinux_enabled = 0;
return 0;
@@ -5752,10 +5749,7 @@ static __init int selinux_init(void)
printk(KERN_INFO "SELinux: Initializing.\n");
/* Set the security state for the initial task. */
- if (cred_alloc_security(current->cred))
- panic("SELinux: Failed to initialize initial task.\n");
- tsec = current->cred->security;
- tsec->osid = tsec->sid = SECINITSID_KERNEL;
+ cred_init_security();
sel_inode_cache = kmem_cache_create("selinux_inode_security",
sizeof(struct inode_security_struct),
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 11167fd567b..e952b397153 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -104,8 +104,7 @@ static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode)
if (rc != 0)
return rc;
- rc = smk_access(current->cred->security, ctp->cred->security,
- MAY_READWRITE);
+ rc = smk_access(current_security(), task_security(ctp), MAY_READWRITE);
if (rc != 0 && capable(CAP_MAC_OVERRIDE))
return 0;
return rc;
@@ -127,8 +126,7 @@ static int smack_ptrace_traceme(struct task_struct *ptp)
if (rc != 0)
return rc;
- rc = smk_access(ptp->cred->security, current->cred->security,
- MAY_READWRITE);
+ rc = smk_access(task_security(ptp), current_security(), MAY_READWRITE);
if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
return 0;
return rc;
@@ -977,22 +975,6 @@ static int smack_file_receive(struct file *file)
*/
/**
- * smack_cred_alloc_security - "allocate" a task cred blob
- * @cred: the task creds in need of a blob
- *
- * Smack isn't using copies of blobs. Everyone
- * points to an immutable list. No alloc required.
- * No data copy required.
- *
- * Always returns 0
- */
-static int smack_cred_alloc_security(struct cred *cred)
-{
- cred->security = current_security();
- return 0;
-}
-
-/**
* smack_cred_free - "free" task-level security credentials
* @cred: the credentials in question
*
@@ -1006,6 +988,30 @@ static void smack_cred_free(struct cred *cred)
}
/**
+ * smack_cred_prepare - prepare new set of credentials for modification
+ * @new: the new credentials
+ * @old: the original credentials
+ * @gfp: the atomicity of any memory allocations
+ *
+ * Prepare a new set of credentials for modification.
+ */
+static int smack_cred_prepare(struct cred *new, const struct cred *old,
+ gfp_t gfp)
+{
+ new->security = old->security;
+ return 0;
+}
+
+/*
+ * commit new credentials
+ * @new: the new credentials
+ * @old: the original credentials
+ */
+static void smack_cred_commit(struct cred *new, const struct cred *old)
+{
+}
+
+/**
* smack_task_setpgid - Smack check on setting pgid
* @p: the task object
* @pgid: unused
@@ -2036,6 +2042,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
static int smack_setprocattr(struct task_struct *p, char *name,
void *value, size_t size)
{
+ struct cred *new;
char *newsmack;
/*
@@ -2058,7 +2065,11 @@ static int smack_setprocattr(struct task_struct *p, char *name,
if (newsmack == NULL)
return -EINVAL;
- p->cred->security = newsmack;
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+ new->security = newsmack;
+ commit_creds(new);
return size;
}
@@ -2354,17 +2365,17 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
/**
* smack_key_alloc - Set the key security blob
* @key: object
- * @tsk: the task associated with the key
+ * @cred: the credentials to use
* @flags: unused
*
* No allocation required
*
* Returns 0
*/
-static int smack_key_alloc(struct key *key, struct task_struct *tsk,
+static int smack_key_alloc(struct key *key, const struct cred *cred,
unsigned long flags)
{
- key->security = tsk->cred->security;
+ key->security = cred->security;
return 0;
}
@@ -2382,14 +2393,14 @@ static void smack_key_free(struct key *key)
/*
* smack_key_permission - Smack access on a key
* @key_ref: gets to the object
- * @context: task involved
+ * @cred: the credentials to use
* @perm: unused
*
* Return 0 if the task has read and write to the object,
* an error code otherwise
*/
static int smack_key_permission(key_ref_t key_ref,
- struct task_struct *context, key_perm_t perm)
+ const struct cred *cred, key_perm_t perm)
{
struct key *keyp;
@@ -2405,11 +2416,10 @@ static int smack_key_permission(key_ref_t key_ref,
/*
* This should not occur
*/
- if (context->cred->security == NULL)
+ if (cred->security == NULL)
return -EACCES;
- return smk_access(context->cred->security, keyp->security,
- MAY_READWRITE);
+ return smk_access(cred->security, keyp->security, MAY_READWRITE);
}
#endif /* CONFIG_KEYS */
@@ -2580,8 +2590,7 @@ struct security_operations smack_ops = {
.ptrace_may_access = smack_ptrace_may_access,
.ptrace_traceme = smack_ptrace_traceme,
.capget = cap_capget,
- .capset_check = cap_capset_check,
- .capset_set = cap_capset_set,
+ .capset = cap_capset,
.capable = cap_capable,
.syslog = smack_syslog,
.settime = cap_settime,
@@ -2630,9 +2639,10 @@ struct security_operations smack_ops = {
.file_send_sigiotask = smack_file_send_sigiotask,
.file_receive = smack_file_receive,
- .cred_alloc_security = smack_cred_alloc_security,
.cred_free = smack_cred_free,
- .task_post_setuid = cap_task_post_setuid,
+ .cred_prepare = smack_cred_prepare,
+ .cred_commit = smack_cred_commit,
+ .task_fix_setuid = cap_task_fix_setuid,
.task_setpgid = smack_task_setpgid,
.task_getpgid = smack_task_getpgid,
.task_getsid = smack_task_getsid,
@@ -2645,7 +2655,6 @@ struct security_operations smack_ops = {
.task_movememory = smack_task_movememory,
.task_kill = smack_task_kill,
.task_wait = smack_task_wait,
- .task_reparent_to_init = cap_task_reparent_to_init,
.task_to_inode = smack_task_to_inode,
.task_prctl = cap_task_prctl,
@@ -2721,6 +2730,8 @@ struct security_operations smack_ops = {
*/
static __init int smack_init(void)
{
+ struct cred *cred;
+
if (!security_module_enable(&smack_ops))
return 0;
@@ -2729,7 +2740,8 @@ static __init int smack_init(void)
/*
* Set the security state for the initial task.
*/
- current->cred->security = &smack_known_floor.smk_known;
+ cred = (struct cred *) current->cred;
+ cred->security = &smack_known_floor.smk_known;
/*
* Initialize locks