diff options
Diffstat (limited to 'security')
-rw-r--r-- | security/capability.c | 21 | ||||
-rw-r--r-- | security/commoncap.c | 265 | ||||
-rw-r--r-- | security/keys/internal.h | 17 | ||||
-rw-r--r-- | security/keys/key.c | 25 | ||||
-rw-r--r-- | security/keys/keyctl.c | 95 | ||||
-rw-r--r-- | security/keys/keyring.c | 14 | ||||
-rw-r--r-- | security/keys/permission.c | 24 | ||||
-rw-r--r-- | security/keys/proc.c | 8 | ||||
-rw-r--r-- | security/keys/process_keys.c | 333 | ||||
-rw-r--r-- | security/keys/request_key.c | 29 | ||||
-rw-r--r-- | security/keys/request_key_auth.c | 41 | ||||
-rw-r--r-- | security/security.c | 58 | ||||
-rw-r--r-- | security/selinux/hooks.c | 286 | ||||
-rw-r--r-- | security/smack/smack_lsm.c | 82 |
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_ |