diff options
Diffstat (limited to 'security/selinux/hooks.c')
-rw-r--r-- | security/selinux/hooks.c | 177 |
1 files changed, 130 insertions, 47 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 794c3ca49ea..419491d8e7d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -53,6 +53,7 @@ #include <net/ip.h> /* for local_port_range[] */ #include <net/sock.h> #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ +#include <net/inet_connection_sock.h> #include <net/net_namespace.h> #include <net/netlabel.h> #include <linux/uaccess.h> @@ -95,10 +96,6 @@ #include "audit.h" #include "avc_ss.h" -#define SB_TYPE_FMT "%s%s%s" -#define SB_SUBTYPE(sb) (sb->s_subtype && sb->s_subtype[0]) -#define SB_TYPE_ARGS(sb) sb->s_type->name, SB_SUBTYPE(sb) ? "." : "", SB_SUBTYPE(sb) ? sb->s_subtype : "" - extern struct security_operations *security_ops; /* SECMARK reference count */ @@ -413,8 +410,8 @@ static int sb_finish_set_opts(struct super_block *sb) the first boot of the SELinux kernel before we have assigned xattr values to the filesystem. */ if (!root_inode->i_op->getxattr) { - printk(KERN_WARNING "SELinux: (dev %s, type "SB_TYPE_FMT") has no " - "xattr support\n", sb->s_id, SB_TYPE_ARGS(sb)); + printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " + "xattr support\n", sb->s_id, sb->s_type->name); rc = -EOPNOTSUPP; goto out; } @@ -422,22 +419,22 @@ static int sb_finish_set_opts(struct super_block *sb) if (rc < 0 && rc != -ENODATA) { if (rc == -EOPNOTSUPP) printk(KERN_WARNING "SELinux: (dev %s, type " - SB_TYPE_FMT") has no security xattr handler\n", - sb->s_id, SB_TYPE_ARGS(sb)); + "%s) has no security xattr handler\n", + sb->s_id, sb->s_type->name); else printk(KERN_WARNING "SELinux: (dev %s, type " - SB_TYPE_FMT") getxattr errno %d\n", sb->s_id, - SB_TYPE_ARGS(sb), -rc); + "%s) getxattr errno %d\n", sb->s_id, + sb->s_type->name, -rc); goto out; } } if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) - printk(KERN_ERR "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), unknown behavior\n", - sb->s_id, SB_TYPE_ARGS(sb)); + printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", + sb->s_id, sb->s_type->name); else - printk(KERN_DEBUG "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), %s\n", - sb->s_id, SB_TYPE_ARGS(sb), + printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", + sb->s_id, sb->s_type->name, labeling_behaviors[sbsec->behavior-1]); sbsec->flags |= SE_SBINITIALIZED; @@ -600,6 +597,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, const struct cred *cred = current_cred(); int rc = 0, i; struct superblock_security_struct *sbsec = sb->s_security; + const char *name = sb->s_type->name; struct inode *inode = sbsec->sb->s_root->d_inode; struct inode_security_struct *root_isec = inode->i_security; u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; @@ -658,8 +656,8 @@ static int selinux_set_mnt_opts(struct super_block *sb, strlen(mount_options[i]), &sid); if (rc) { printk(KERN_WARNING "SELinux: security_context_to_sid" - "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n", - mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc); + "(%s) failed for (dev %s, type %s) errno=%d\n", + mount_options[i], sb->s_id, name, rc); goto out; } switch (flags[i]) { @@ -806,8 +804,7 @@ out: out_double_mount: rc = -EINVAL; printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " - "security settings for (dev %s, type "SB_TYPE_FMT")\n", sb->s_id, - SB_TYPE_ARGS(sb)); + "security settings for (dev %s, type %s)\n", sb->s_id, name); goto out; } @@ -2480,8 +2477,8 @@ static int selinux_sb_remount(struct super_block *sb, void *data) rc = security_context_to_sid(mount_options[i], len, &sid); if (rc) { printk(KERN_WARNING "SELinux: security_context_to_sid" - "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n", - mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc); + "(%s) failed for (dev %s, type %s) errno=%d\n", + mount_options[i], sb->s_id, sb->s_type->name, rc); goto out_free_opts; } rc = -EINVAL; @@ -2519,8 +2516,8 @@ out_free_secdata: return rc; out_bad_option: printk(KERN_WARNING "SELinux: unable to change security options " - "during remount (dev %s, type "SB_TYPE_FMT")\n", sb->s_id, - SB_TYPE_ARGS(sb)); + "during remount (dev %s, type=%s)\n", sb->s_id, + sb->s_type->name); goto out_free_opts; } @@ -3828,7 +3825,7 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) u32 nlbl_sid; u32 nlbl_type; - err = selinux_skb_xfrm_sid(skb, &xfrm_sid); + err = selinux_xfrm_skb_sid(skb, &xfrm_sid); if (unlikely(err)) return -EACCES; err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); @@ -3846,6 +3843,30 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) return 0; } +/** + * selinux_conn_sid - Determine the child socket label for a connection + * @sk_sid: the parent socket's SID + * @skb_sid: the packet's SID + * @conn_sid: the resulting connection SID + * + * If @skb_sid is valid then the user:role:type information from @sk_sid is + * combined with the MLS information from @skb_sid in order to create + * @conn_sid. If @skb_sid is not valid then then @conn_sid is simply a copy + * of @sk_sid. Returns zero on success, negative values on failure. + * + */ +static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid) +{ + int err = 0; + + if (skb_sid != SECSID_NULL) + err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid); + else + *conn_sid = sk_sid; + + return err; +} + /* socket security operations */ static int socket_sockcreate_sid(const struct task_security_struct *tsec, @@ -4452,7 +4473,7 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct sk_security_struct *sksec = sk->sk_security; int err; u16 family = sk->sk_family; - u32 newsid; + u32 connsid; u32 peersid; /* handle mapped IPv4 packets arriving via IPv6 sockets */ @@ -4462,16 +4483,11 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, err = selinux_skb_peerlbl_sid(skb, family, &peersid); if (err) return err; - if (peersid == SECSID_NULL) { - req->secid = sksec->sid; - req->peer_secid = SECSID_NULL; - } else { - err = security_sid_mls_copy(sksec->sid, peersid, &newsid); - if (err) - return err; - req->secid = newsid; - req->peer_secid = peersid; - } + err = selinux_conn_sid(sksec->sid, peersid, &connsid); + if (err) + return err; + req->secid = connsid; + req->peer_secid = peersid; return selinux_netlbl_inet_conn_request(req, family); } @@ -4731,6 +4747,7 @@ static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops, static unsigned int selinux_ip_output(struct sk_buff *skb, u16 family) { + struct sock *sk; u32 sid; if (!netlbl_enabled()) @@ -4739,8 +4756,27 @@ static unsigned int selinux_ip_output(struct sk_buff *skb, /* we do this in the LOCAL_OUT path and not the POST_ROUTING path * because we want to make sure we apply the necessary labeling * before IPsec is applied so we can leverage AH protection */ - if (skb->sk) { - struct sk_security_struct *sksec = skb->sk->sk_security; + sk = skb->sk; + if (sk) { + struct sk_security_struct *sksec; + + if (sk->sk_state == TCP_LISTEN) + /* if the socket is the listening state then this + * packet is a SYN-ACK packet which means it needs to + * be labeled based on the connection/request_sock and + * not the parent socket. unfortunately, we can't + * lookup the request_sock yet as it isn't queued on + * the parent socket until after the SYN-ACK is sent. + * the "solution" is to simply pass the packet as-is + * as any IP option based labeling should be copied + * from the initial connection request (in the IP + * layer). it is far from ideal, but until we get a + * security label in the packet itself this is the + * best we can do. */ + return NF_ACCEPT; + + /* standard practice, label using the parent socket */ + sksec = sk->sk_security; sid = sksec->sid; } else sid = SECINITSID_KERNEL; @@ -4810,27 +4846,36 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, * as fast and as clean as possible. */ if (!selinux_policycap_netpeer) return selinux_ip_postroute_compat(skb, ifindex, family); + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = selinux_peerlbl_enabled(); + if (!secmark_active && !peerlbl_active) + return NF_ACCEPT; + + sk = skb->sk; + #ifdef CONFIG_XFRM /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec * packet transformation so allow the packet to pass without any checks * since we'll have another chance to perform access control checks * when the packet is on it's final way out. * NOTE: there appear to be some IPv6 multicast cases where skb->dst - * is NULL, in this case go ahead and apply access control. */ - if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL) + * is NULL, in this case go ahead and apply access control. + * NOTE: if this is a local socket (skb->sk != NULL) that is in the + * TCP listening state we cannot wait until the XFRM processing + * is done as we will miss out on the SA label if we do; + * unfortunately, this means more work, but it is only once per + * connection. */ + if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL && + !(sk != NULL && sk->sk_state == TCP_LISTEN)) return NF_ACCEPT; #endif - secmark_active = selinux_secmark_enabled(); - peerlbl_active = selinux_peerlbl_enabled(); - if (!secmark_active && !peerlbl_active) - return NF_ACCEPT; - /* if the packet is being forwarded then get the peer label from the - * packet itself; otherwise check to see if it is from a local - * application or the kernel, if from an application get the peer label - * from the sending socket, otherwise use the kernel's sid */ - sk = skb->sk; if (sk == NULL) { + /* Without an associated socket the packet is either coming + * from the kernel or it is being forwarded; check the packet + * to determine which and if the packet is being forwarded + * query the packet directly to determine the security label. */ if (skb->skb_iif) { secmark_perm = PACKET__FORWARD_OUT; if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) @@ -4839,7 +4884,45 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, secmark_perm = PACKET__SEND; peer_sid = SECINITSID_KERNEL; } + } else if (sk->sk_state == TCP_LISTEN) { + /* Locally generated packet but the associated socket is in the + * listening state which means this is a SYN-ACK packet. In + * this particular case the correct security label is assigned + * to the connection/request_sock but unfortunately we can't + * query the request_sock as it isn't queued on the parent + * socket until after the SYN-ACK packet is sent; the only + * viable choice is to regenerate the label like we do in + * selinux_inet_conn_request(). See also selinux_ip_output() + * for similar problems. */ + u32 skb_sid; + struct sk_security_struct *sksec = sk->sk_security; + if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) + return NF_DROP; + /* At this point, if the returned skb peerlbl is SECSID_NULL + * and the packet has been through at least one XFRM + * transformation then we must be dealing with the "final" + * form of labeled IPsec packet; since we've already applied + * all of our access controls on this packet we can safely + * pass the packet. */ + if (skb_sid == SECSID_NULL) { + switch (family) { + case PF_INET: + if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + break; + case PF_INET6: + if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + default: + return NF_DROP_ERR(-ECONNREFUSED); + } + } + if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid)) + return NF_DROP; + secmark_perm = PACKET__SEND; } else { + /* Locally generated packet, fetch the security label from the + * associated socket. */ struct sk_security_struct *sksec = sk->sk_security; peer_sid = sksec->sid; secmark_perm = PACKET__SEND; |