aboutsummaryrefslogtreecommitdiff
path: root/security
diff options
context:
space:
mode:
Diffstat (limited to 'security')
-rw-r--r--security/capability.c19
-rw-r--r--security/keys/compat.c3
-rw-r--r--security/keys/gc.c1
-rw-r--r--security/keys/internal.h1
-rw-r--r--security/keys/keyctl.c102
-rw-r--r--security/keys/process_keys.c49
-rw-r--r--security/security.c17
-rw-r--r--security/selinux/hooks.c28
-rw-r--r--security/smack/smack_lsm.c30
-rw-r--r--security/tomoyo/tomoyo.c17
10 files changed, 267 insertions, 0 deletions
diff --git a/security/capability.c b/security/capability.c
index 06400cf0775..93a2ffe6590 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -373,6 +373,11 @@ static int cap_task_create(unsigned long clone_flags)
return 0;
}
+static int cap_cred_alloc_blank(struct cred *cred, gfp_t gfp)
+{
+ return 0;
+}
+
static void cap_cred_free(struct cred *cred)
{
}
@@ -386,6 +391,10 @@ static void cap_cred_commit(struct cred *new, const struct cred *old)
{
}
+static void cap_cred_transfer(struct cred *new, const struct cred *old)
+{
+}
+
static int cap_kernel_act_as(struct cred *new, u32 secid)
{
return 0;
@@ -836,6 +845,13 @@ static int cap_key_getsecurity(struct key *key, char **_buffer)
return 0;
}
+static int cap_key_session_to_parent(const struct cred *cred,
+ const struct cred *parent_cred,
+ struct key *key)
+{
+ return 0;
+}
+
#endif /* CONFIG_KEYS */
#ifdef CONFIG_AUDIT
@@ -961,9 +977,11 @@ 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_blank);
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, cred_transfer);
set_to_cap_if_null(ops, kernel_act_as);
set_to_cap_if_null(ops, kernel_create_files_as);
set_to_cap_if_null(ops, kernel_module_request);
@@ -1063,6 +1081,7 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, key_free);
set_to_cap_if_null(ops, key_permission);
set_to_cap_if_null(ops, key_getsecurity);
+ set_to_cap_if_null(ops, key_session_to_parent);
#endif /* CONFIG_KEYS */
#ifdef CONFIG_AUDIT
set_to_cap_if_null(ops, audit_rule_init);
diff --git a/security/keys/compat.c b/security/keys/compat.c
index c766c68a63b..792c0a611a6 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -82,6 +82,9 @@ asmlinkage long compat_sys_keyctl(u32 option,
case KEYCTL_GET_SECURITY:
return keyctl_get_security(arg2, compat_ptr(arg3), arg4);
+ case KEYCTL_SESSION_TO_PARENT:
+ return keyctl_session_to_parent();
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/gc.c b/security/keys/gc.c
index 44adc325e15..1e616aef55f 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -65,6 +65,7 @@ static void key_gc_timer_func(unsigned long data)
* - return true if we altered the keyring
*/
static bool key_gc_keyring(struct key *keyring, time_t limit)
+ __releases(key_serial_lock)
{
struct keyring_list *klist;
struct key *key;
diff --git a/security/keys/internal.h b/security/keys/internal.h
index fb830514c33..24ba0307b7a 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -201,6 +201,7 @@ extern long keyctl_set_timeout(key_serial_t, unsigned);
extern long keyctl_assume_authority(key_serial_t);
extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
size_t buflen);
+extern long keyctl_session_to_parent(void);
/*
* debugging key validation
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 736d7800f97..74c96852459 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1228,6 +1228,105 @@ long keyctl_get_security(key_serial_t keyid,
return ret;
}
+/*
+ * attempt to install the calling process's session keyring on the process's
+ * parent process
+ * - the keyring must exist and must grant us LINK permission
+ * - implements keyctl(KEYCTL_SESSION_TO_PARENT)
+ */
+long keyctl_session_to_parent(void)
+{
+ struct task_struct *me, *parent;
+ const struct cred *mycred, *pcred;
+ struct cred *cred, *oldcred;
+ key_ref_t keyring_r;
+ int ret;
+
+ keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
+ if (IS_ERR(keyring_r))
+ return PTR_ERR(keyring_r);
+
+ /* our parent is going to need a new cred struct, a new tgcred struct
+ * and new security data, so we allocate them here to prevent ENOMEM in
+ * our parent */
+ ret = -ENOMEM;
+ cred = cred_alloc_blank();
+ if (!cred)
+ goto error_keyring;
+
+ cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
+ keyring_r = NULL;
+
+ me = current;
+ write_lock_irq(&tasklist_lock);
+
+ parent = me->real_parent;
+ ret = -EPERM;
+
+ /* the parent mustn't be init and mustn't be a kernel thread */
+ if (parent->pid <= 1 || !parent->mm)
+ goto not_permitted;
+
+ /* the parent must be single threaded */
+ if (atomic_read(&parent->signal->count) != 1)
+ goto not_permitted;
+
+ /* the parent and the child must have different session keyrings or
+ * there's no point */
+ mycred = current_cred();
+ pcred = __task_cred(parent);
+ if (mycred == pcred ||
+ mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
+ goto already_same;
+
+ /* the parent must have the same effective ownership and mustn't be
+ * SUID/SGID */
+ if (pcred-> uid != mycred->euid ||
+ pcred->euid != mycred->euid ||
+ pcred->suid != mycred->euid ||
+ pcred-> gid != mycred->egid ||
+ pcred->egid != mycred->egid ||
+ pcred->sgid != mycred->egid)
+ goto not_permitted;
+
+ /* the keyrings must have the same UID */
+ if (pcred ->tgcred->session_keyring->uid != mycred->euid ||
+ mycred->tgcred->session_keyring->uid != mycred->euid)
+ goto not_permitted;
+
+ /* the LSM must permit the replacement of the parent's keyring with the
+ * keyring from this process */
+ ret = security_key_session_to_parent(mycred, pcred,
+ key_ref_to_ptr(keyring_r));
+ if (ret < 0)
+ goto not_permitted;
+
+ /* if there's an already pending keyring replacement, then we replace
+ * that */
+ oldcred = parent->replacement_session_keyring;
+
+ /* the replacement session keyring is applied just prior to userspace
+ * restarting */
+ parent->replacement_session_keyring = cred;
+ cred = NULL;
+ set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
+
+ write_unlock_irq(&tasklist_lock);
+ if (oldcred)
+ put_cred(oldcred);
+ return 0;
+
+already_same:
+ ret = 0;
+not_permitted:
+ put_cred(cred);
+ return ret;
+
+error_keyring:
+ key_ref_put(keyring_r);
+ return ret;
+}
+
/*****************************************************************************/
/*
* the key control system call
@@ -1313,6 +1412,9 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
(char __user *) arg3,
(size_t) arg4);
+ case KEYCTL_SESSION_TO_PARENT:
+ return keyctl_session_to_parent();
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 4739cfbb41b..5c23afb31ec 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -17,6 +17,7 @@
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/mutex.h>
+#include <linux/security.h>
#include <linux/user_namespace.h>
#include <asm/uaccess.h>
#include "internal.h"
@@ -768,3 +769,51 @@ error:
abort_creds(new);
return ret;
}
+
+/*
+ * Replace a process's session keyring when that process resumes userspace on
+ * behalf of one of its children
+ */
+void key_replace_session_keyring(void)
+{
+ const struct cred *old;
+ struct cred *new;
+
+ if (!current->replacement_session_keyring)
+ return;
+
+ write_lock_irq(&tasklist_lock);
+ new = current->replacement_session_keyring;
+ current->replacement_session_keyring = NULL;
+ write_unlock_irq(&tasklist_lock);
+
+ if (!new)
+ return;
+
+ old = current_cred();
+ new-> uid = old-> uid;
+ new-> euid = old-> euid;
+ new-> suid = old-> suid;
+ new->fsuid = old->fsuid;
+ new-> gid = old-> gid;
+ new-> egid = old-> egid;
+ new-> sgid = old-> sgid;
+ new->fsgid = old->fsgid;
+ new->user = get_uid(old->user);
+ new->group_info = get_group_info(old->group_info);
+
+ new->securebits = old->securebits;
+ new->cap_inheritable = old->cap_inheritable;
+ new->cap_permitted = old->cap_permitted;
+ new->cap_effective = old->cap_effective;
+ new->cap_bset = old->cap_bset;
+
+ new->jit_keyring = old->jit_keyring;
+ new->thread_keyring = key_get(old->thread_keyring);
+ new->tgcred->tgid = old->tgcred->tgid;
+ new->tgcred->process_keyring = key_get(old->tgcred->process_keyring);
+
+ security_transfer_creds(new, old);
+
+ commit_creds(new);
+}
diff --git a/security/security.c b/security/security.c
index f88eaf6b14c..d8b727637f0 100644
--- a/security/security.c
+++ b/security/security.c
@@ -684,6 +684,11 @@ int security_task_create(unsigned long clone_flags)
return security_ops->task_create(clone_flags);
}
+int security_cred_alloc_blank(struct cred *cred, gfp_t gfp)
+{
+ return security_ops->cred_alloc_blank(cred, gfp);
+}
+
void security_cred_free(struct cred *cred)
{
security_ops->cred_free(cred);
@@ -699,6 +704,11 @@ void security_commit_creds(struct cred *new, const struct cred *old)
security_ops->cred_commit(new, old);
}
+void security_transfer_creds(struct cred *new, const struct cred *old)
+{
+ security_ops->cred_transfer(new, old);
+}
+
int security_kernel_act_as(struct cred *new, u32 secid)
{
return security_ops->kernel_act_as(new, secid);
@@ -1241,6 +1251,13 @@ int security_key_getsecurity(struct key *key, char **_buffer)
return security_ops->key_getsecurity(key, _buffer);
}
+int security_key_session_to_parent(const struct cred *cred,
+ const struct cred *parent_cred,
+ struct key *key)
+{
+ return security_ops->key_session_to_parent(cred, parent_cred, key);
+}
+
#endif /* CONFIG_KEYS */
#ifdef CONFIG_AUDIT
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c3bb31ecc5a..134a9c0d200 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3233,6 +3233,21 @@ static int selinux_task_create(unsigned long clone_flags)
}
/*
+ * allocate the SELinux part of blank credentials
+ */
+static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
+{
+ struct task_security_struct *tsec;
+
+ tsec = kzalloc(sizeof(struct task_security_struct), gfp);
+ if (!tsec)
+ return -ENOMEM;
+
+ cred->security = tsec;
+ return 0;
+}
+
+/*
* detach and free the LSM part of a set of credentials
*/
static void selinux_cred_free(struct cred *cred)
@@ -3264,6 +3279,17 @@ static int selinux_cred_prepare(struct cred *new, const struct cred *old,
}
/*
+ * transfer the SELinux data to a blank set of creds
+ */
+static void selinux_cred_transfer(struct cred *new, const struct cred *old)
+{
+ const struct task_security_struct *old_tsec = old->security;
+ struct task_security_struct *tsec = new->security;
+
+ *tsec = *old_tsec;
+}
+
+/*
* set the security data for a kernel service
* - all the creation contexts are set to unlabelled
*/
@@ -5469,8 +5495,10 @@ static struct security_operations selinux_ops = {
.dentry_open = selinux_dentry_open,
.task_create = selinux_task_create,
+ .cred_alloc_blank = selinux_cred_alloc_blank,
.cred_free = selinux_cred_free,
.cred_prepare = selinux_cred_prepare,
+ .cred_transfer = selinux_cred_transfer,
.kernel_act_as = selinux_kernel_act_as,
.kernel_create_files_as = selinux_kernel_create_files_as,
.kernel_module_request = selinux_kernel_module_request,
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index c243a2b2583..969f5fee190 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1080,6 +1080,22 @@ static int smack_file_receive(struct file *file)
*/
/**
+ * smack_cred_alloc_blank - "allocate" blank task-level security credentials
+ * @new: the new credentials
+ * @gfp: the atomicity of any memory allocations
+ *
+ * Prepare a blank set of credentials for modification. This must allocate all
+ * the memory the LSM module might require such that cred_transfer() can
+ * complete without error.
+ */
+static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
+{
+ cred->security = NULL;
+ return 0;
+}
+
+
+/**
* smack_cred_free - "free" task-level security credentials
* @cred: the credentials in question
*
@@ -1117,6 +1133,18 @@ static void smack_cred_commit(struct cred *new, const struct cred *old)
}
/**
+ * smack_cred_transfer - Transfer the old credentials to the new credentials
+ * @new: the new credentials
+ * @old: the original credentials
+ *
+ * Fill in a set of blank credentials from another set of credentials.
+ */
+static void smack_cred_transfer(struct cred *new, const struct cred *old)
+{
+ new->security = old->security;
+}
+
+/**
* smack_kernel_act_as - Set the subjective context in a set of credentials
* @new: points to the set of credentials to be modified.
* @secid: specifies the security ID to be set
@@ -3073,9 +3101,11 @@ struct security_operations smack_ops = {
.file_send_sigiotask = smack_file_send_sigiotask,
.file_receive = smack_file_receive,
+ .cred_alloc_blank = smack_cred_alloc_blank,
.cred_free = smack_cred_free,
.cred_prepare = smack_cred_prepare,
.cred_commit = smack_cred_commit,
+ .cred_transfer = smack_cred_transfer,
.kernel_act_as = smack_kernel_act_as,
.kernel_create_files_as = smack_kernel_create_files_as,
.task_setpgid = smack_task_setpgid,
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index 35a13e7915e..9548a0984cc 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -14,6 +14,12 @@
#include "tomoyo.h"
#include "realpath.h"
+static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
+{
+ new->security = NULL;
+ return 0;
+}
+
static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
gfp_t gfp)
{
@@ -25,6 +31,15 @@ static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
return 0;
}
+static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
+{
+ /*
+ * Since "struct tomoyo_domain_info *" is a sharable pointer,
+ * we don't need to duplicate.
+ */
+ new->security = old->security;
+}
+
static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
{
int rc;
@@ -262,7 +277,9 @@ static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
*/
static struct security_operations tomoyo_security_ops = {
.name = "tomoyo",
+ .cred_alloc_blank = tomoyo_cred_alloc_blank,
.cred_prepare = tomoyo_cred_prepare,
+ .cred_transfer = tomoyo_cred_transfer,
.bprm_set_creds = tomoyo_bprm_set_creds,
.bprm_check_security = tomoyo_bprm_check_security,
#ifdef CONFIG_SYSCTL