diff options
Diffstat (limited to 'security/smack/smack_lsm.c')
| -rw-r--r-- | security/smack/smack_lsm.c | 147 |
1 files changed, 89 insertions, 58 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 94dc9d406ce3..60b4217b9b68 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -52,6 +52,7 @@ #define SMK_SENDING 2 #ifdef SMACK_IPV6_PORT_LABELING +DEFINE_MUTEX(smack_ipv6_lock); static LIST_HEAD(smk_ipv6_port_list); #endif static struct kmem_cache *smack_inode_cache; @@ -347,8 +348,6 @@ static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, struct smack_rule *orp; int rc = 0; - INIT_LIST_HEAD(nhead); - list_for_each_entry_rcu(orp, ohead, list) { nrp = kzalloc(sizeof(struct smack_rule), gfp); if (nrp == NULL) { @@ -375,8 +374,6 @@ static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, struct smack_known_list_elem *nklep; struct smack_known_list_elem *oklep; - INIT_LIST_HEAD(nhead); - list_for_each_entry(oklep, ohead, list) { nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp); if (nklep == NULL) { @@ -1009,15 +1006,39 @@ static int smack_inode_alloc_security(struct inode *inode) } /** - * smack_inode_free_security - free an inode blob + * smack_inode_free_rcu - Free inode_smack blob from cache + * @head: the rcu_head for getting inode_smack pointer + * + * Call back function called from call_rcu() to free + * the i_security blob pointer in inode + */ +static void smack_inode_free_rcu(struct rcu_head *head) +{ + struct inode_smack *issp; + + issp = container_of(head, struct inode_smack, smk_rcu); + kmem_cache_free(smack_inode_cache, issp); +} + +/** + * smack_inode_free_security - free an inode blob using call_rcu() * @inode: the inode with a blob * - * Clears the blob pointer in inode + * Clears the blob pointer in inode using RCU */ static void smack_inode_free_security(struct inode *inode) { - kmem_cache_free(smack_inode_cache, inode->i_security); - inode->i_security = NULL; + struct inode_smack *issp = inode->i_security; + + /* + * The inode may still be referenced in a path walk and + * a call to smack_inode_permission() can be made + * after smack_inode_free_security() is called. + * To avoid race condition free the i_security via RCU + * and leave the current inode->i_security pointer intact. + * The inode will be freed after the RCU grace period too. + */ + call_rcu(&issp->smk_rcu, smack_inode_free_rcu); } /** @@ -1626,6 +1647,9 @@ static int smack_file_ioctl(struct file *file, unsigned int cmd, struct smk_audit_info ad; struct inode *inode = file_inode(file); + if (unlikely(IS_PRIVATE(inode))) + return 0; + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); smk_ad_setfield_u_fs_path(&ad, file->f_path); @@ -1655,6 +1679,9 @@ static int smack_file_lock(struct file *file, unsigned int cmd) int rc; struct inode *inode = file_inode(file); + if (unlikely(IS_PRIVATE(inode))) + return 0; + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); smk_ad_setfield_u_fs_path(&ad, file->f_path); rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); @@ -1681,6 +1708,9 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd, int rc = 0; struct inode *inode = file_inode(file); + if (unlikely(IS_PRIVATE(inode))) + return 0; + switch (cmd) { case F_GETLK: break; @@ -1734,6 +1764,9 @@ static int smack_mmap_file(struct file *file, if (file == NULL) return 0; + if (unlikely(IS_PRIVATE(file_inode(file)))) + return 0; + isp = file_inode(file)->i_security; if (isp->smk_mmap == NULL) return 0; @@ -1934,12 +1967,9 @@ static int smack_file_open(struct file *file, const struct cred *cred) struct smk_audit_info ad; int rc; - if (smack_privileged(CAP_MAC_OVERRIDE)) - return 0; - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); smk_ad_setfield_u_fs_path(&ad, file->f_path); - rc = smk_access(tsp->smk_task, smk_of_inode(inode), MAY_READ, &ad); + rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); rc = smk_bu_credfile(cred, file, MAY_READ, rc); return rc; @@ -2272,25 +2302,6 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info, } /** - * smack_task_wait - Smack access check for waiting - * @p: task to wait for - * - * Returns 0 - */ -static int smack_task_wait(struct task_struct *p) -{ - /* - * Allow the operation to succeed. - * Zombies are bad. - * In userless environments (e.g. phones) programs - * get marked with SMACK64EXEC and even if the parent - * and child shouldn't be talking the parent still - * may expect to know when the child exits. - */ - return 0; -} - -/** * smack_task_to_inode - copy task smack into the inode blob * @p: task to copy from * @inode: inode to copy to @@ -2353,6 +2364,20 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) */ static void smack_sk_free_security(struct sock *sk) { +#ifdef SMACK_IPV6_PORT_LABELING + struct smk_port_label *spp; + + if (sk->sk_family == PF_INET6) { + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_sock != sk) + continue; + spp->smk_can_reuse = 1; + break; + } + rcu_read_unlock(); + } +#endif kfree(sk->sk_security); } @@ -2603,17 +2628,20 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) * on the bound socket. Take the changes to the port * as well. */ - list_for_each_entry(spp, &smk_ipv6_port_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { if (sk != spp->smk_sock) continue; spp->smk_in = ssp->smk_in; spp->smk_out = ssp->smk_out; + rcu_read_unlock(); return; } /* * A NULL address is only used for updating existing * bound entries. If there isn't one, it's OK. */ + rcu_read_unlock(); return; } @@ -2629,16 +2657,23 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) * Look for an existing port list entry. * This is an indication that a port is getting reused. */ - list_for_each_entry(spp, &smk_ipv6_port_list, list) { - if (spp->smk_port != port) + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port || spp->smk_sock_type != sock->type) continue; + if (spp->smk_can_reuse != 1) { + rcu_read_unlock(); + return; + } spp->smk_port = port; spp->smk_sock = sk; spp->smk_in = ssp->smk_in; spp->smk_out = ssp->smk_out; + spp->smk_can_reuse = 0; + rcu_read_unlock(); return; } - + rcu_read_unlock(); /* * A new port entry is required. */ @@ -2650,8 +2685,12 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) spp->smk_sock = sk; spp->smk_in = ssp->smk_in; spp->smk_out = ssp->smk_out; + spp->smk_sock_type = sock->type; + spp->smk_can_reuse = 0; - list_add(&spp->list, &smk_ipv6_port_list); + mutex_lock(&smack_ipv6_lock); + list_add_rcu(&spp->list, &smk_ipv6_port_list); + mutex_unlock(&smack_ipv6_lock); return; } @@ -2702,14 +2741,16 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, return 0; port = ntohs(address->sin6_port); - list_for_each_entry(spp, &smk_ipv6_port_list, list) { - if (spp->smk_port != port) + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type) continue; object = spp->smk_in; if (act == SMK_CONNECTING) ssp->smk_packet = spp->smk_out; break; } + rcu_read_unlock(); return smk_ipv6_check(skp, object, address, act); } @@ -3438,6 +3479,13 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) case PIPEFS_MAGIC: isp->smk_inode = smk_of_current(); break; + case SOCKFS_MAGIC: + /* + * Socket access is controlled by the socket + * structures associated with the task involved. + */ + isp->smk_inode = &smack_known_star; + break; default: isp->smk_inode = sbsp->smk_root; break; @@ -3454,19 +3502,12 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) */ switch (sbp->s_magic) { case SMACK_MAGIC: - case PIPEFS_MAGIC: - case SOCKFS_MAGIC: case CGROUP_SUPER_MAGIC: /* * Casey says that it's a little embarrassing * that the smack file system doesn't do * extended attributes. * - * Casey says pipes are easy (?) - * - * Socket access is controlled by the socket - * structures associated with the task involved. - * * Cgroupfs is special */ final = &smack_known_star; @@ -3620,7 +3661,6 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value) /** * smack_setprocattr - Smack process attribute setting - * @p: the object task * @name: the name of the attribute in /proc/.../attr * @value: the value to set * @size: the size of the value @@ -3630,8 +3670,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value) * * Returns the length of the smack label or an error code */ -static int smack_setprocattr(struct task_struct *p, char *name, - void *value, size_t size) +static int smack_setprocattr(const char *name, void *value, size_t size) { struct task_smack *tsp = current_security(); struct cred *new; @@ -3639,13 +3678,6 @@ static int smack_setprocattr(struct task_struct *p, char *name, struct smack_known_list_elem *sklep; int rc; - /* - * Changing another process' Smack value is too dangerous - * and supports no sane use case. - */ - if (p != current) - return -EPERM; - if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel)) return -EPERM; @@ -3849,7 +3881,7 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, * ambient value. */ rcu_read_lock(); - list_for_each_entry(skp, &smack_known_list, list) { + list_for_each_entry_rcu(skp, &smack_known_list, list) { if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) continue; /* @@ -4667,7 +4699,6 @@ static struct security_hook_list smack_hooks[] = { LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler), LSM_HOOK_INIT(task_movememory, smack_task_movememory), LSM_HOOK_INIT(task_kill, smack_task_kill), - LSM_HOOK_INIT(task_wait, smack_task_wait), LSM_HOOK_INIT(task_to_inode, smack_task_to_inode), LSM_HOOK_INIT(ipc_permission, smack_ipc_permission), @@ -4819,7 +4850,7 @@ static __init int smack_init(void) /* * Register with LSM */ - security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks)); + security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack"); return 0; } |