diff options
Diffstat (limited to 'security/selinux/hooks.c')
| -rw-r--r-- | security/selinux/hooks.c | 119 |
1 files changed, 74 insertions, 45 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c106167423a1..3cdc5a22004a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2764,6 +2764,14 @@ static int selinux_mount(const char *dev_name, return path_has_perm(cred, path, FILE__MOUNTON); } +static int selinux_move_mount(const struct path *from_path, + const struct path *to_path) +{ + const struct cred *cred = current_cred(); + + return path_has_perm(cred, to_path, FILE__MOUNTON); +} + static int selinux_umount(struct vfsmount *mnt, int flags) { const struct cred *cred = current_cred(); @@ -3006,14 +3014,14 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, if (IS_ERR(isec)) return PTR_ERR(isec); - return avc_has_perm(&selinux_state, - sid, isec->sid, isec->sclass, FILE__READ, &ad); + return avc_has_perm_flags(&selinux_state, + sid, isec->sid, isec->sclass, FILE__READ, &ad, + rcu ? MAY_NOT_BLOCK : 0); } static noinline int audit_inode_permission(struct inode *inode, u32 perms, u32 audited, u32 denied, - int result, - unsigned flags) + int result) { struct common_audit_data ad; struct inode_security_struct *isec = selinux_inode(inode); @@ -3024,7 +3032,7 @@ static noinline int audit_inode_permission(struct inode *inode, rc = slow_avc_audit(&selinux_state, current_sid(), isec->sid, isec->sclass, perms, - audited, denied, result, &ad, flags); + audited, denied, result, &ad); if (rc) return rc; return 0; @@ -3071,7 +3079,11 @@ static int selinux_inode_permission(struct inode *inode, int mask) if (likely(!audited)) return rc; - rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags); + /* fall back to ref-walk if we have to generate audit */ + if (flags & MAY_NOT_BLOCK) + return -ECHILD; + + rc2 = audit_inode_permission(inode, perms, audited, denied, rc); if (rc2) return rc2; return rc; @@ -5461,44 +5473,6 @@ static int selinux_tun_dev_open(void *security) return 0; } -static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb) -{ - int err = 0; - u32 perm; - struct nlmsghdr *nlh; - struct sk_security_struct *sksec = sk->sk_security; - - if (skb->len < NLMSG_HDRLEN) { - err = -EINVAL; - goto out; - } - nlh = nlmsg_hdr(skb); - - err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm); - if (err) { - if (err == -EINVAL) { - pr_warn_ratelimited("SELinux: unrecognized netlink" - " message: protocol=%hu nlmsg_type=%hu sclass=%s" - " pig=%d comm=%s\n", - sk->sk_protocol, nlh->nlmsg_type, - secclass_map[sksec->sclass - 1].name, - task_pid_nr(current), current->comm); - if (!enforcing_enabled(&selinux_state) || - security_get_allow_unknown(&selinux_state)) - err = 0; - } - - /* Ignore */ - if (err == -ENOENT) - err = 0; - goto out; - } - - err = sock_has_perm(sk, perm); -out: - return err; -} - #ifdef CONFIG_NETFILTER static unsigned int selinux_ip_forward(struct sk_buff *skb, @@ -5827,7 +5801,60 @@ static unsigned int selinux_ipv6_postroute(void *priv, static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) { - return selinux_nlmsg_perm(sk, skb); + int rc = 0; + unsigned int msg_len; + unsigned int data_len = skb->len; + unsigned char *data = skb->data; + struct nlmsghdr *nlh; + struct sk_security_struct *sksec = sk->sk_security; + u16 sclass = sksec->sclass; + u32 perm; + + while (data_len >= nlmsg_total_size(0)) { + nlh = (struct nlmsghdr *)data; + + /* NOTE: the nlmsg_len field isn't reliably set by some netlink + * users which means we can't reject skb's with bogus + * length fields; our solution is to follow what + * netlink_rcv_skb() does and simply skip processing at + * messages with length fields that are clearly junk + */ + if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len) + return 0; + + rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm); + if (rc == 0) { + rc = sock_has_perm(sk, perm); + if (rc) + return rc; + } else if (rc == -EINVAL) { + /* -EINVAL is a missing msg/perm mapping */ + pr_warn_ratelimited("SELinux: unrecognized netlink" + " message: protocol=%hu nlmsg_type=%hu sclass=%s" + " pid=%d comm=%s\n", + sk->sk_protocol, nlh->nlmsg_type, + secclass_map[sclass - 1].name, + task_pid_nr(current), current->comm); + if (enforcing_enabled(&selinux_state) && + !security_get_allow_unknown(&selinux_state)) + return rc; + rc = 0; + } else if (rc == -ENOENT) { + /* -ENOENT is a missing socket/class mapping, ignore */ + rc = 0; + } else { + return rc; + } + + /* move to the next message after applying netlink padding */ + msg_len = NLMSG_ALIGN(nlh->nlmsg_len); + if (msg_len >= data_len) + return 0; + data_len -= msg_len; + data += msg_len; + } + + return rc; } static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass) @@ -6788,6 +6815,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts), LSM_HOOK_INIT(sb_add_mnt_opt, selinux_add_mnt_opt), + LSM_HOOK_INIT(move_mount, selinux_move_mount), + LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security), LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as), |