diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/capability.c | 19 | ||||
| -rw-r--r-- | security/keys/compat.c | 3 | ||||
| -rw-r--r-- | security/keys/gc.c | 1 | ||||
| -rw-r--r-- | security/keys/internal.h | 1 | ||||
| -rw-r--r-- | security/keys/keyctl.c | 102 | ||||
| -rw-r--r-- | security/keys/process_keys.c | 49 | ||||
| -rw-r--r-- | security/security.c | 17 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 28 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 30 | ||||
| -rw-r--r-- | security/tomoyo/tomoyo.c | 17 |
10 files changed, 267 insertions, 0 deletions
diff --git a/security/capability.c b/security/capability.c index 06400cf..93a2ffe 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 c766c68..792c0a6 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 44adc32..1e616ae 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 fb83051..24ba030 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 736d780..74c9685 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 4739cfb..5c23afb 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 f88eaf6..d8b7276 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 c3bb31e..134a9c0 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 c243a2b..969f5fe 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 35a13e7..9548a09 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 |
